摘要:

ANALYST, JULY 1992, VOL. 117 1175 Spectrophotometric Determination of Titanium(1v) Using Chromotropic Acid and a Flow Injection Manifold Rajesh Purohit" and Surekha Devit Department of Chemistry, Faculty of Science, M. S. University, Baroda-390 002, India Micro-amounts of titanium(1v) were determined spectrophotometrically using a flow injection manifold and chromotropic acid as a complexing reagent. The various experimental conditions were optimized for the determination of titanium(1v) at 443 nm. Linear calibration was achieved over a titanium concentration range of 5 x 10-54.7 x 10-4 mot dm-3. The limit of detection of the proposed method was 25 ng. The method was applied to the determination of titanium in bauxite. Keywords: Titanium( iv); spectrophotometry; chromotropic acid; flow injection; bauxite Continuous-flow methods have been developed extensively for the determination of many metals and non-metals.However, methods for the determination of titanium are limited14 and require inductively coupled plasma,* spectro- fluorimetric3 or chemiluminescence detectors.4 Recently, spectrophotometric flow injection methods for titanium have been reported.5.6 However, although they are sensitive the procedures involved are complex. Chromotropic acid and its 2,7-dichloro derivative7-9 have been used for the determination of titanium in alloys and minerals by conventional methods. It has been reported that chromotropic acid7 forms two types of complexes with titanium. The more sensitive yellow complex, due to its instability, is not useful for the determination of titanium by conventional methods.Flow injection methods have the inherent advantage of overcoming the drawback of instability of the complex formed during measurement, and in this work we developed a simple, inexpensive, rapid and sensitive continuous-flow method based on Ti'"-chromotropic acid complex formation for the determination of micro-amounts of titanium. Experimental The chemicals used were of analytical-reagent grade and de-ionized water was used throughout. Acetate buffers of different pH values were prepared from 0.2 mol dm-3 sodium acetate solution and acetic acid. Chromotropic acid stock solution (0.25% m/v) was prepared whenever required. Titanium(1v) stock solution of 1 mg cm-3 was prepared by dissolving 1.8329 g of potassium titanyl oxalate in water and diluting to 250 cm3.Working solutions of titanium were prepared by appropriate dilution. A flow injection manifold was constructed as shown in Fig. 1, using a microtube peristaltic pump, Rheodyne Model 5020 injection valve, 0.5 mm i.d. poly(tetrafluoroethy1ene) (PTFE) tubing and an ultraviolet/visible spectrophotometric detector with a 20 mm3 flow cell. The absorbance-time response was recorded on an x-t chart recorder at 443 nm. Analysis of Bauxite The analysis of bauxite ore was carried out by fusing 1 g of bauxite [British Chemical Standard (BCS) Certified Refer- ence Material (CRM) No. 3951 with a mixture of sodium carbonate and potassium carbonate (6 + 1 m/m) for 3 h at 800-1000 "C. The melted mass was cooled and treated with * Present address: Gujarat Jalseva Training Institute, Gandhinagar- t To whom correspondence should be addressed.382 015, India. HCI (1 + 99 v/v) and evaporated to dryness. The residue was dissolved in HCl (1 + 9 v/v) and filtered. The filtrate was diluted to 100 cm3 and the silica residue was discarded. A 10 cm3 volume of the filtrate was treated with 10 cm3 of 5% m/v potassium oxalate solution to mask iron and aluminium and the titanium was determined by following the proposed method. Results and Discussion Optimization of pH A 5.22 x 10-5 mol dm-3 titanium(1v) solution was injected into a stream of acetate buffer of pH 1-9. Chromotropic acid (0.25% d v ) of pH 1-9 was used in the other channel, as shown in Fig. 1. The complex was formed on passage of the reagent and metal solution through the reaction coil.The Buffer solution 1 / 3 4 - Reagent Fig. 1 FI manifold for on-line determination of titanium using chromotropic acid as a reagent. 1, Peristaltic pump; 2, injection valve; 3, three-way key; and 4, detector (ultraviolet/visible spectropho- tometer) r 0 0.2 0.4 Concentration of reagent (% m/v) Fig. 2 titanium, 20 mm3 of 5.22 x 10-5 mol dm-3 Effect of pH on absorbance. Chromotropic acid, 0.25% d v ;1176 ANALYST, JULY 1992, VOL. 117 maximum extent of complex formation was observed to be at pH 5 (Fig. 2). The molar absorptivity of the complex was 4.5 x 104 dm3 mol-1 cm-1. This indicates that the complex formed is different to the earlier reported complexes,7 which had optimum pH values of 1 4 and 3-7.It is well known that the pH profiles and other parameters differ for continuous-flow methods and conventional batch processes. We have reported similar observations for the preconcentration of zinc, cad- miurn10 and lead.11 Optimization of Reagent Concentration Chromotropic acid of pH 5 and of concentration 0.02-0.25% m/v was passed through the reagent channel of the manifold shown in Fig. 1. The flow rate was maintained at 3 cm3 min-1 and 20 mm3 of 5.22 x 10-5 mol dm-3 titanium were injected into the buffer stream. The optimum concentration of the reagent required for the development of the TiIv-chromo- tropic acid complex was 0.2% (Fig. 3). The effect of sample volume was studied by varying the sample volume injected into the flow manifold (5.2 x 10-5 mol dm-3 titanium) from 10 to 50 mm3.As expected, the absorbance showed a linear increase with increasing sample volume. Variations of the flow rates of buffer and reagent from 0.5 to 5.0 cm3 min-1 showed that at 0.5 cm3 min-1 broadening of the 8 B g 2.0 - ln n Q 1.0 - 0 4 8 PH Fig. 3 Optimization of reagent concentration. Titanium, 20 mm3 of 5.22 x 10-5 mol dm-3; acetate buffer, pH 5 ; reagent, 0.25% m/v (PH 5 ) ~~~~ ~ ~ - Scan Fig. 4 Calibration plot for titanium peak is considerable. At flow rates from 1 to 3 cm3 min-1 there was no significant change in the peak heights. The use of a reaction coil longer than 20 cm increases the dispersion. Hence a short reaction coil of 10 cm was used. This also indicates instantaneous complex formation. A calibration graph for 5.22 X 10-54.7 x 10-4 mol dm-3 titanium(1v) solutions was recorded in triplicate under opti- mized conditions, viz., pH 5, flow rate 3 cm3 min-1, reagent concentration 0.25% m/v and reaction coil length 10 cm.The results are presented in Fig. 4. The regression coefficient of the linear plot was 0.9986 and the least-squares equation of the peak height absorbance was A, = 0.0165 [TiIV (pg cm-3)] - 5.83 X 10-3 The limit of detection (twice the blank noise) was 25 ng and the relative standard deviation of the calibration results was Interferences due to various cations in the determination of 8 pg cm-3 of titanium by a conventional batch process were studied by using 50-500-fold excess concentrations of the cations (Table 1). It is observed that the method is reasonably free from interferences.Interferences due to A P , Fe", Pb" and Vv can be eliminated by using 1 cm3 of 5% m/v potassium oxalate, thiourea, sodium thiosulfate and 1 ,lo-phenanthroline as masking reagents, respectively. Copper(1r) and Crvl do not interfere if they are present at levels less than 20 and 80 times the titanium concentration, respectively. Aluminium inter- feres even when it is present in a 1 : 1 ratio with respect to titanium. In the determination of titanium, the interference from up to a 200-fold excess concentration of aluminium could be masked by using 5 cm3 of 5% m/v potassium oxalate. The determination of 8 pg of titanium was carried out in the presence of various concentrations of A P , FelI and Pb", using the masking reagents mentioned in Table 1.The results are given in Table 2. Acetate, thiocyanate, iodide, thiourea, thiosulfate, glycinate and ascorbate do not interfere even at very high concentrations, whereas tartrate, citrate, 5-sulfo- salicylic acid and ethylenediaminetetraacetic acid (EDTA) interfere. Table 1 Effect of foreign ions on the determination of titanium. Ti'", 8 pg cm-3; reagent, 2 cm3 of 0.25% d v chromotropic acid solution; pH, 5 4 % (n = 5). Ion Tolerance Masking reagent added limidpg cm-3 (5% d v ) Al"' Cu" Fell Nil1 Cd" Zn" Pb" CrVi CO" vv 0 Potassium oxalate 200 - 100 Thiourea or potassium oxalate 3000 - 3000 - 3000 - 300 Sodium thiosulfate 6 0 0 - 3000 - 200 1 ,lo-Phenanthroline Table 2 Results for the determination of 8.0 pg of titanium(rv) Ratio of Ti Interfering to interfering RSD ion ion (m/m) Ti'"found/pg (%)* A P 1 : 10 1 : 50 1 : 100 Fell1 1 : 10 1:50 1 : 100 Pb" 1 : 10 1:50 1 : 100 * n = 3 .7.92 8.01 8.06 8.02 8.05 8.02 7.92 8.01 8.07 0.2 0.1 0.1 0.1 0.2 0.1 0.1 0.2 0.2ANALYST, JULY 1992, VOL. 117 1177 Analysis of Bauxite The amount of titanium in bauxite ore (BCS CRM No. 395) was determined by the proposed method and was found to be 1.85% (mean of five determinations). The relative standard deviation was calculated to be 1.36%. The certified value for titanium in the ore is 1.93%. The determination of titanium was also carried out using a standard procedure involving hydrogen peroxide12 and was found to be 2.01%. The results obtained by the two methods are in reasonable agreement. 4 5 6 7 8 9 10 11 12 References 1 Mochizuki, T., and Kuroda, R., Analyst, 1982, 107, 1255. 2 Hirata, S. U., and Yoshini, V. M., Anal. Chem., 1986,58,2602. 3 Lazaro, F., Luque de Castro, M. D., and Valcircel, M., Anal. Lett., Part A , 1985, 18, 1209. Alwarthan, A. A., and Townshend, A., Anal. Chim. Acta, 1987,1%, 135. Almuoibed, A. M., and Townshend, A,, Fresenius' Z. Anal. Chem., 1989,335, 905. Muiioz, M., Alonso, J., Bartroli, J., and Valiente, M., Analyst, 1990, 115,315. Busev, A. I., Tiptsova, V. S., and Ivanov, V. M., Analytical Chemistry of Rare Elements, Mir, Moscow, 1981, p. 137. Brandt, W., and Preiser, A. M., Anal. Chem., 1953,25, 567. Kuznetsov, V. I., and Basargin, N. N., 2%. Anal. Khim., 1961, 16, 573. Purohit, R., and Devi, S., Analyst, 1991, 116, 825. Purohit, R., and Devi, S., Anal. Chim. Acta, 1992, 259, 53. Vogel, A. I., Quantitative Inorganic Analysis, Longman, London, 3rd edn., 1961, p. 788. Paper 1102284I Received May 15, 1991 Accepted March 2, 1992

ISSN:0003-2654    

DOI:10.1039/AN9921701175

出版商:RSC    

年代:1992

数据来源: RSC

摘要:

ANALYST, JULY 1992, VOL. 117 1179 Simplex-optimized and Flow Injection Spectrophotometric Assay of Tetracycline Antibiotics in Drug Formulations Salah M. Sultan, Fakhr-Eldin 0. Suliman, Salih 0. Duffuaa and ldeisan 1. Abu-Abdoun Chemistry Department, King Fahd University, Dhahran 31261, Saudi Arabia The modified simplex method was applied to the selection of the proper experimental conditions for the flow injection spectrophotometric determination of tetracycline, chlortetracycline, oxytetracycline and demeclocy- cline. In the method a 157 mm3 sample volume was injected, for all the compounds, into the carrier stream of iron(iii) of concentrations 554, 626, 701 and 447 ppm flowing at rates of 3.72, 4.37, 3.72 and 3.72 cm3 min-1, thus passing through a reaction coil of length 55,85,45 and 45 cm for the respective compounds, all in 0.001 mol dm-3 sulfuric acid as an over-all reaction medium.A high sampling frequency of the order of at least 170 h-1 was attained for all the compounds. A high precision with a relative standard deviation of less than 0.9% ( n = 5 ) was also obtained. The accuracy was found to be high as the Student t-values were calculated to be less than the theoretical values when the results were compared with those obtained by the conventional spectrophotometric method. There were no interferences from excipients in dosage forms when the method was applied to pharmaceutical preparations. Keywords: Simplex method; flow injection; spectrophotometry; tetracycline antibiotics; drug formulations Tetracyclines and derivatives are extensively used in current therapy owing to their broad-spectrum antibacterial activity.Tetracycline hydrochloride, oxytetracycline, chlortetracycline and demeclocycline hyclate have recently been assayed spectrophotometricallyl through complexation with iron(m) in sulfuric acid media and subsequent measurement of the soluble brown complex formed at the corresponding wavelength. The introduction of flow injection (FI) and the trend to utilize this technique for routine and batch analyses led us to apply it to drug formulations to maximize the sensitivity and response and to optimize the throughput and economy of the drugs and other reagents. However, the failure of the iterative univariate procedure to achieve the highest throughput with the lowest concentrations of reagents in a recent FI method for the determination of oxytetra- cycline,2 probably owing to relatively high interactions of FI and chemical variables, necessitated the use of a modified computerized simplex method3-5 with a program designed for the optimization of the FI system and chemical variables. Few FI methods for the assay of tetracyclines have been reported; one requires a special and complicated ampero- metric detector6 and another a chemiluminescence detector suitable for the determination of tetracycline only at relatively high concentrations with poor detection limits.7 Both methods require the use of a difficult buffering procedure and suffer low throughput.The official British Pharmacopoeia1 (BP) method is tedious and time consuming, requiring prolonged incubation .* Other methods for the assay of tetracycline and its derivatives using different techniques such as chromato- graphy, electrochemistry and spectrophotometry have been reviewed elsewhere, 1,239 and each has advantages and disad- vantages.Experimental Apparatus Apparatus obtained from the Alitea USA/FIA Laboratory (Sweden) was used for all experimental work. The apparatus, which has been described previously , l o consists of a four- channel peristaltic pump, a Rheodyne Model 5041 injector, a reactor module, a Spectronic Mini 20 spectrophotometer as a detector with a 20 mm3 ultra-micro flow-through cell having a pathlength of 1.0 mm and a Cole Parmer Model 0555 single-channel strip-chart recorder. A Perkin-Elmer Lambda 5 ul traviolethisible spectropho- tometer with 10.00 mm cells was used for measuring the absorbances of samples prepared for analysis by the original spectrophotometric method1 for comparison purposes.Reagents Tetracycline standard solution This was freshly prepared from the pure compounds supplied by Pfizer (Belgium) by directly dissolving the powder in 0.001 mol dm-3 sulfuric acid to give a lo00 ppm stock solution, from which other concentrations were prepared by appropriate dilution. Oxytetracycline required warming at 60 "C for 20 min, whereas the others dissolved at room temperature. Tetracycline proprietary drugs Capsules. The contents of ten capsules were carefully transferred into a beaker and accurately weighed. An amount of powder equivalent to 250 mg of the drug was dissolved in 150 cm3 of 0.001 mol dm-3 sulfuric acid, warmed at 60 "C for 20 min and transferred into a 250 cm3 calibrated flask through a filter-paper, cooled to room temperature and diluted to the mark with the same sulfuric acid.Syrups. A volume of syrup containing a certain mass of the tetracycline was pipetted into a suitable calibrated flask and diluted to the mark with the required sulfuric acid solution to give a final solution of the drug in 0.001 rnol dm-3 acid. Iron( 11 I) A 5.6 mg cm-3 iron(m) solution was prepared by dissolving exactly 24.2000 g of dried ammonium iron(I11) sulfate [NH4Fe- (S04)2.12H20] in 400 cm3 of 0.001 mol dm-3 sulfuric acid and diluting to 500 cm3 with the same acid in a calibrated flask. Manifold The single-configuration FI manifold is shown in Fig.1. Poly(viny1 chloride) (PVC) tubing of 1.3 mm i d . was used as pump tubing for the carrier stream. A Rheodyne Model 5041 four-way poly(tetrafluoroethy1ene) (PTFE) rotary valve with a 157 mm3 sample loop was used for injecting the sample into the carrier stream. Poly(tetrafluoroethy1ene) tubing of 0.5 mm i.d. and different lengths (55 cm for tetracycline, 45 cm for oxytetracycline and demeclocycline and 85 cm for chlor- tetracycline) was used as reactor coils.1180 ANALYST, JULY 1992, VOL. 117 I I tl XY U w Fig. 1 Schematic diagram of the FI manifold used: R, reagent carrier of iron(m) in sulfuric acid; P, peristaltic pump; S, sample injector of 157 mm3 loop size; C, reaction coil; D, Spectronic Mini 20 spectrophotometer; XY, recorder; and W, waste Optimization and Procedure The parameters of the program and the upper and lower boundaries for each variable were fed into the computer.Five experiments were designed according to the procedure suggested by Betteridge and co-workers11J2 as the initial simplex, as the simplex is a geometric figure whose vertices are n + 1, where n is the number of variables. Solutions were prepared accordingly, the carrier stream was allowed to flow for a few minutes at a certain flow rate and the baseline absorbance was adjusted to zero for both the spectropho- tometer and recorder. The drug sample was injected into the flowing stream and the absorbance of the coloured complex was recorded at the corresponding maximum wavelength. The absorbance values of each of the five initial experiments were entered into the computer and the program calculated the next single set of conditions to be prepared and tried.The process continued in this way until satisfactory results were obtained. Samples of unknown concentrations were then analysed and the results were calculated by comparing the absorbance given by the sample with the calibration equation for the generic drug under investigation. Results and Discussion Chemical System As reported earlier,' tetracycline, oxytetracycline, chlor- tetracycline and demeclocycline react with iron(II1) in sulfuric acid instantly forming soluble, stable, brown complexes with absorption maxima at 423,435,435 and 435 nm, respectively, and according to the reaction scheme shown below.c,H3 ,CH3 ' y' OH 0 OH 0 0 CH-, OH N C-NHZ 0 0 O H 0 \ / Fe3+, +2H+ ; I I E l I 0.65 100 140 180 220 Sample vo lu me/m m3 Fig. 2 Effect of variation of the sample loop size on absorbance for: 1, 680 p m demeclocycline; 2, 600 ppm oxytetracycline; 3, 460 ppm tetracyclne hydrochloride; and 4, 450 ppm chlortetracycline Table 1 Simplex optimization of chemical and FI variables for tetracycline hydrochloride Experiment Coil Flow rate/ [H2S04]/ [1ron(111)] Peak No.* lengthkm cm3 min-1 rnol dm-3 (ppm) absorbance 1 100 4.78 0.050 100 0.198 2 300 4.78 0.050 100 0.192 3 45 5.31 0.050 100 0.162 4 45 3.90 0.010 300 0.516 5 45 3.90 0.100 600 0.372 6R 200 3.72 0.055 450 0.408 7 c 84 4.12 0.030 290 0.381 8R 136 3.72 0.046 544 0.462 9 c 81 4.04 0.029 311 0.402 10R 45 3.72 0.035 649 0.528 11E 45 3.72 0.028 924 0.528 12R 82 3.99 0.001 311 0.738 13E 101 4.03 0.001 167 0.720 14R 56 3.84 0.006 528 0.708 15C 85 3.99 0.009 293 0.588 16R 55 3.72 0.001 554 0.840 17E 45 3.72 0.001 688 0.828 18R 93 3.83 0.009 736 0.648 19C 57 3.79 0.005 602 0.690 20 99 4.05 0.001 50 0.558 * R = reflection; C = contraction; E = expansion.The univariate method of optimization was used to study the effect of changing the sample loop size as it was expected to have little influence on absorbance, and this was confirmed as shown in Fig. 2. The effect of change of loop size between 110 and 210 mm3 was studied under various conditions, with Fig. 2 showing a typical cycle in which the flow rate, reaction coil length, iron(II1) concentration and sulfuric acid concentration, respectively, were as follows for the four compounds: 4.10 cm3 min-1, 85 cm, 600 pprn and 0.001 mol dm-3 for tetracycline; 3.80 cm3 min-1, 100 cm, 600 ppm and 0.001 mol dm-3 for oxytetracycline; 3.81 cm3 min-1, 140 cm, 600 pprn and 0.001 mol dm-3 for chlortetracycline; and 3.77 cm3 min-1,100 cm, 600 ppm and 0.001 mol dm-3 for demeclocycline.The optimum volume found and used in all other experiments was 157 mm3 for all the compounds. Having fixed the sample loop size, the flow rate, reaction coil length, iron(w) concentration and acid concentration variables were optimized by the modified simplex procedure for each compound independently as follows. Tetracycline Table 1 gives the result of the four-variable optimization. Points 1-5 represent the first cycle and cover an optimization area of 2040%.The best point attained was point 4 with a peak absorbance of 0.516 and the worst was point 3 with a peak absorbance of 0.162. Therefore, point 3 was reflectedANALYST, JULY 1992, VOL. 117 1181 through the centroid of other points to obtain point 6. An experiment was then performed utilizing the variable setting as the reflected point and an absorbance of 0.408 was obtained. As this value was better than that at point 3, the latter was rejected and replaced with point 6. A contraction was then performed, as this point was not better than the best point, point 4. Then, by using the experimental setting of variables generated by contraction, a peak absorbance of 0.384 was obtained, which was not better than the reflection point; hence this completes the cycle.The reflection point 10 gave an absorbance better than the best one leading to an expansion point, the absorbance of which was the same as that at the reflection point, and therefore the reflection point replaced the worst point of the previous simplex. Point 16 represents the highest response obtained. However, attempts were made to make further improvements towards maximiza- tion, but this was found to necessitate additional experiments and was deemed not to be worthwhile, so the procedure was halted. The optimum conditions for the assay of tetracycline were: sample volume 157 mm3, flow rate 3.72 cm3 min-1, reaction coil length 55 cm, iron(m) 554 pprn and sulfuric acid 0.001 mol dm-3. Chlortetracycline Table 2 summarizes the four-variable optimization, which clearly indicates that point 17 offers the highest absorbance, and at this point it became obvious that further improvement was not possible and further continuation to point 21 resulted in no significant improvement. Therefore, the optimum conditions for the assay of chlortetracycline were: sample volume 157 mm3, flow rate 4.37 cm3 min-1, reaction coil length 85 cm, iron(m) 626 pprn and sulfuric acid 0.001 mol dm-3.Oxytetracy cline In Table 3 , it is clear that a total of 19 experiments were performed and it was then found convenient to halt further experimentation. Point 15 gave the highest absorbance and the optimum conditions were: sample volume 157 mm3, flow rate 3.72 cm3 min-1, reaction coil length 45 cm, iron(rI1) 701 ppm and sulfuric acid 0.001 rnol dm-3.Table 2 Simplex optimization of chemical and FI variables for chlorte trac ycline Experiment Coil Flow rate/ [H2S04]/ [Iron(in)] Peak No.* lengthkm cm3 min-1 rnol dm-3 (ppm) absorbance 1 100 4.87 0.0500 100 0.204 2 400 4.87 0.0500 100 0.168 3 45 5.31 0.0500 100 0.186 4 45 3.90 0.1OOO 300 0.27 5 45 3.90 0.0100 600 0.576 6R 45 4.61 0.0750 200 0.258 7 c 96 4.32 0.0360 375 0.423 8R 98 3.89 0.0680 337 0.324 9 c 58 4.25 0.0350 409 0.426 10R 50 3.80 0.06oO 492 0.378 11c 60 4.11 0.0330 448 0.474 12R 85 4.40 0.0017 466 0.756 13E 104 4.65 0.0010 549 0.786 14R 65 4.08 0.0049 552 0.744 15C 83 4.40 0.0100 515 0.606 16R 76 4.29 0.0010 566 0.792 17E 85 4.37 0.0010 626 0.810 18R 91 4.46 0.0010 534 0.780 19C 86 4.40 0.0023 575 0.768 20R 91 4.47 0.0013 612 0.792 21c 86 4.40 0.0012 583 0.780 * R = reflection; C = contraction; E = expansion.Derneclocycline As indicated in Table 4, a total of 26 experiments were required to decide the optimum conditions and the system did not merit further experimentation to improve the response. Point 20 gave the best response and the highest absorbance value of 1.098. The optimum conditions were: sample volume 157 mm3, flow rate 3.72 cm3 min-1, reaction coil length 45 cm, iron(m) 447 pprn and sulfuric acid 0.001 mol dm-3. For all the compounds investigated, 0.001 mol dm-3 sulfuric acid was found to be the optimum concentration for the determination, which is in agreement with the conventional spectrophotometric method.' Poorer responses were always obtained at higher acid concentrations, indicating dissociation of the complex at higher acidities.The relatively high flow rate and short reaction coil length for all the compounds confirms that the reaction kinetics and Table 3 Simplex optimization of chemical and F I variables for ox ytetracycline Experiment Coil Flow rate/ [H2S04]/ [Iron(iir)] Peak No.* lengthkm cm3 min-1 rnol dm-3 (ppm) absorbance 1 100 4.78 0.050 100 0.198 2 300 4.78 0.050 100 0.186 3 45 5.31 0.050 100 0.168 4 45 3.90 0.010 300 0.462 5 45 3.90 0.100 600 0.36 6R 200 3.72 0.055 450 0.288 7 c 84 4.12 0.031 288 0.378 8R 45 3.72 0.046 544 0.402 9 c 56 4.04 0.029 311 0.384 10R 45 3.72 0.035 649 0.564 11E 45 3.72 0.028 924 0.564 12R 70 4.00 0.001 311 0.702 13E 82 4.03 0.001 167 0.642 14R 45 3.73 0.002 563 0.72 15E 45 3.72 0.001 701 0.786 16R 52 3.72 0.001 734 0.768 17C 49 3.78 0.005 612 0.696 18R 66 3.73 0.008 902 0.660 19C 50 3.77 0.005 651 0.702 * R = reflection; C = contraction; E = expansion.Table 4 Simplex optimization of chemical and FI variables for demeclocycline Experiment Coil Flow rate/ [H2S04]/ [Iron(i~i)] Peak No.* lengthkm cm3 min-1 rnol dm-3 (ppm) absorbance 1 100 4.78 0.0500 100 0.312 2 400 4.78 0.0500 100 0.324 3 45 5.31 0.0500 100 0.252 4 45 3.90 0.0100 300 0.780 5 45 3.90 0.1OOO 600 0.570 6R 250 3.72 0.0550 450 0.546 7 c 96 4.12 0.0310 288 0.570 8R 193 3.72 0.0460 544 0.714 9 c 96 4.04 0.0290 311 0.654 10R 45 3.72 0.0350 649 0.774 11c 58 3.94 0.0270 337 0.720 12R 45 3.77 0.0520 487 0.660 13C 53 3.92 0.0260 345 0.738 14R 80 4.00 0.0010 50 0.264 15Red 45 3.90 0.0550 450 0.546 16R 80 4.00 0.0010 196 0.63 17C 54 3.93 0.0160 312 0.72 18R 45 3.81 0.0100 335 0.87 20E 45 3.72 0.0010 447 1.098 21R 45 3.79 0.0010 314 1.080 22c 47 3.79 0.0070 336 0.954 23R 45 3.74 0.0060 352 0.984 24C 46 3.78 O.Oo60 340 0.972 25R 45 3.72 0.0010 318 1.080 26C 45 3.76 0.0040 339 0.954 * R = reflection; C = contraction; E = expansion; Red = reduction.1182 ANALYST, JULY 1992, VOL.117 rate of formation of the complex are fast. The lower response values obtained when using longer reaction coil lengths could be attributed to dispersion.13 Analytical Appraisals The FI method was run for each compound using series of drug standards. Typical FI results are shown in Fig. 3 for chlortetracycline in the range 40-300 ppm, indicating excel- lent reproducibility.Beer's law for the four compounds was found to be valid in the ranges 20-200, 40-300, 40-260 and 20-220 ppm for tetracycline, chlortetracycline, oxytetracy- cline and demeclocycline, with the calibration equations A = 0.999), A = 0.00245 + 0.0019~ ( r = 1.00) and A = 0.00870 + 0.0027~ ( r = 0.998), respectively, where A is absorbance, c is the concentration of the tetracycline (mol dm-3) and r is the correlation coefficient. The peak width at 60% of the peak height was calculated as a measure of the total sample dispersion and was found to be 3, 2.4, 2.4 and 2.8 s for the above four compounds, respectively, thus indicating poor dispersion. In all instances the relative standard deviation was less than 0.9% (n = 5) and a sample throughput of at least 170 h-1 was attained, which is ten times the throughput attained by the previous method for oxytetracycline .2 -0.0249 + 0.0026~ ( r = 0.999), A = -0.0160 + 0.0023~ ( r = 0.600 I r n I Application and Statistical Evaluation The method was applied to the determination of tetracycline and its derivatives in proprietary drugs in both capsules and injection formulations (Table 5).The capsules are for human treatment and the injection form is for camels. The recorder tracings in Fig. 4 show good reproducibility with relative standard deviations within the standard calibration range. The results, when compared with the spectrophotometric method,' indicated no interferences either from excipients added to capsules or from those added to syrups such as starch, glucose and sugar.Moreover, the presence of gluco- samine hydrochloride in the proprietary drug Latycin and sodium metaphosphate in Hostacycline P capsules also showed no interference in the proposed method, whereas the presence of phosphate in the latter drug caused large interferences in the spectrophotometric method, which could be attributed to the fact that phosphate equilibrates in acidic media and buffers the solution, raising its pH and leading to higher absorbances and high results. This effect was minimal in the FI method as only micro-amounts are used. Finally, the Student's t-test values indicated high precision. 0.450 r 6 $ 0.300 C (0 e s m 2 a 0.450 Q, c n 0.300 2 0.150 n 0.150 0 c Time - Time Fig. 3 Typical FI calibration graph for a series of standard chlortetracycline solutions of 1,40; 2,60; 3,80; 4,100; 5,120; 6,140; 7, 160; 8, 180; 9,200; 10, 220; 11,260; 12, 280; and 13, 300 ppm Fig.4 Typical FI recorder tracings for: 1, Oxytetracycline syrup, 200 mg cm-3; 2, Terramycin capsules, 250 mg; 3, Balkacycline capsules, 250 mg; 4, Latycin G capsules, 250 mg; 5, Hostacycline capsules, 500 mg; and 6, Dumocycline capsules, 250 mg Table 5 Results of the analysis of pharmaceutical products containing tetracycline hydrochloride and oxytetracycline by the proposed method and the conventional spectrophotometric method Mean recovery f SD (%)* Drug Dumocycline capsules Hostacycline P capsules Latycin capsules Balkacycline capsules Terram ycin capsules Oxytetracycline 20% L.A. injection * n = 5 . t Ref. 1. $ c theoretical = 2.31, n = 5.Supplier Stated contents Dumex, Denmark Tetracycline HCl Hoechst, Germany Tetracycline HCl 250 mg 500 mg, sodium hexametaphosphate 220 mg Biochemie, Austria Tetracycline HCl 250 mg, glucosamine HCI 250 mg Arab Pharmaceutical Tetracycline HCl Manufacturing, 250 mg Jordan Pfizer, Belgium Oxytetrac ycline Dopharma, Oxytetracycline The Netherlands 200 mg cm-3 250 mg FI method 99.72 k 0.42 102.31 f 0.65 104.23 k 0.46 101.79 f 0.58 99.62 f 0.87 99.21 k 0.63 Conventional spectrophotometric method? 101.88 k 0.46 122.88 * 0.55 98.78 f 0.73 103.19 k 0.46 103.72 k 0.62 102.19 k 0.56 f$ 1.15 - 1.71 1.63 1.99 1.23ANALYST, JULY 1992, VOL. 117 1183 Conclusion The proposed method is as accurate as other reported methods but is more suitable for the assay of tetracyclines in drug formulations as it does not suffer interferences from excipients and other common additives in such compounds.Being an FI method, it has the distinct advantage of providing high sample throughputs and shorter times are required for analysis. The chemical system permitted the successful application of the modified simplex method of optimization, the maximum response with optimum operating conditions being reached faster and with a smaller number of experiments than with the iterative univariate method. One of the authors (F.-E. 0. S.) is indebted to KFUPM for offering an M.Sc. scholarship. The authors thank Pfizer (Belgium) for donating the drugs. Thanks are also due to M. Fahmi for technical assistance. References 1 Sultan, S. M., Al-Zarnil, I. Z., and Al-Arfaj, N. A., Talanta, 1988, 35, 375. 2 3 4 5 6 7 8 9 10 11 12 13 Alwarthan, A. A., Al-Tamrah, S. A., and Sultan, S. M., Analyst, 1991, 116, 183. Nelder, J. A., and Mead, R., Comput. J., 1965, 7 , 308. Spendley, W., Hext, G. R., and Himsworth, F. R., Techno- metrics, 1962, 441. Morgan, S. L., and Deming, S. N., Anal. Chem., 1974,46,1170. Ji, H., and Wang, E., Analyst, 1988, 113, 1541. Alwarthan, A. A., and Al-Tarnrah, S. A., Anal. Chim. Acta, 1987, 196, 135. British Pharmacopoeia 1980, HM Stationery Office, London, 1980. Sultan, S. M., Analyst, 1986, 111, 97. Sultan, S. M., Analyst, 1991, 116, 177. Betteridge, D., Sly, T. J., Wade, A. P., and Tillrnan, J. E. W., Anal. Chem., 1983, 55, 1292. Betteridge, D., Wade, A. P., and Howard, A. G., Talanta, 1985,32,723. RGBiEka, J., and Hansen, E. H., Flow Injection Anaysis, Wiley, New York, 2nd edn., 1988. Paper 1f05701 D Received November 11, 1991 Accepted February 12, 1992

ISSN:0003-2654    

DOI:10.1039/AN9921701179

出版商:RSC    

年代:1992

数据来源: RSC

摘要:

ANALYST, JULY 1992, VOL. 117 1185 Light Scattering Method for the Determination of Trace Amounts of Phosphate Using a Cationic Water-soluble Porphyrin Masaaki Tabata and Keisuke Harada Department of Chemistry, Faculty of Science and Engineering, Saga University, 7, Honjo-machi, Saga 840, Japan A sensitive and simple method is described for the determination of phosphate at the ppb level based on light scattering of the ion pair formed by the reaction of molybdophosphate with tetrakis(1-methyl- pyridinium-4-yl)porphyrin (H2tmpyp4+). The light scattering intensity was measured in the range 300-800 nm under irradiation by a spectrofluorimeter and the maximum intensity was observed at 475 nm. The molar ratio of H2tmpyp4+ to molybdophosphate was 1 : 1 in sulfuric acid. Cations and anions usually encountered in natural water, including silicate and chloride (0.5 mol dm-3), did not interfere with the determination of phosphate. The proposed method was applied to the determination of phosphate in river, sea- and tap water samples.Keywords: Light scattering; phosphate determination; natural waters; porph yrin; ion-pair formation Porphyrins are attractive from an analytical point of view because of their very high molar absorptivity, reaching several hundred thousand dm3 mol-1 cm-1 in the range 400-500 nm (the so-called Soret band). 1 Further, porphyrins are selec- tively accumulated in tumours and readily form complexes with anionic polymers such as deoxyribonucleic acid (DNA), ribonucleic acid (RNA) and nucleotides.2~3 Therefore, porphyrins are used in the diagnosis and photodynamic treatment of cancer.We have found that cationic water-soluble porphyrins react with molybdophosphate, which is an anionic polymer, and give a marked enhancement of the intensity of light scattering even at ppb levels of phosphate. This paper describes a light scattering method for the determination of phosphate using 5,10,15,20-tetrakis( 1-methylpyridinium-4-y1)porphyrin (H2tmpyp4+; Fig. 1). The method is based on light scattering of the ion pair formed between the cationic water-soluble porphyrin and molybdophosphate, which is produced by the reaction of ammonium molybdate with orthophosphoric acid in acidic medium. The intensity of light scattering of the ion pair is proportional to the concentration of phosphate at ppb levels; silicate and chloride do not interfere with the determi- nation.The optimum conditions for the determination of phosphate are discussed and the method was applied to the analysis of tap, river and sea-water samples. Although several methods for the determination of trace amounts of phosphate in natural water samples have been reported, the proposed method does not require any preconcentration such as solvent extraction,475 collection on a membrane filter6 and gel-phase absorption .7 This is the first reported application of light scattering to the determination of trace amounts of phosphate. Experimental Reagents All reagents were of analytical-reagent grade, and all solutions were prepared in water that had been de-ionized and redistilled from alkaline permanganate. Acid-washed glass- ware was used to avoid contamination by phosphate.Tetrakis( 1-methylpyridinium-4-y1)porphyrin ( H2tmpyp4+). Purchased as the tosylate salt from Dojindo Laboratory, Kumamoto, Japan, and converted into the nitrate by passing it through an anion-exchange resin; this was necessary as tosylate reacts with H2tmpyp4+ at high concentrations. Standard phosphate solution. Dissolve 1.433 g of potassium dihydrogen phosphate, previously dried at 110 "C, in distilled water to give a 1.00 mg dm-3 phosphate solution (0.326 mg dm-3 P-Po43-) and dilute the solution accurately before use. Ammonium molybdate solution. Dissolve 7.724 g of ammo- nium heptamolybdate tetrahydrate in distilled water, add 94 cm3 of concentrated sulfuric acid and dilute to 1 dm3.This solution is 6.25 x 10-3 mol dm-3 molybdate in 1.68 mol dm-3 sulfuric acid. Measurements Light scattering intensity was measured in a direction perpen- dicular to the incident light using a Shimadzu RF-510 spectrofluorimeter with a 1 cm light path cell and the scattered spectra were recorded in the range 300400 nm at 5 nm intervals of incident light between 300 and 800 nm. The scattering intensity was standardized with Emulsion G27, which is a homogeneous colloidal solution containing butyl 2-propenoate, methyl 2-methylpropenoate and 2-methyl- propenoate. All experiments were carried out at 25 "C. Results and Discussion Phosphate reacts with ammonium molybdate in acidic medium to form molybdophosphate, which can form an ion pair with H4tmpyp6+ according to the following reaction: H4tmPYP6; PO4+ + 12Mo042- -+ PMoI2Oa3- [H4tmpyp6+ 1 [PMo12040~ - 1 (1) Fig. 1 Structure of 5,10,15,2O-tetrakis( 1-methylpyridinium-4- yl)porphyrin(H2tmpyp4+)ANALYST, JULY 1992, VOL.117 300 400 500 600 Irradiation wavelength (Wnm Fig. 2 Light scattering spectra of the ion pair of molybdophosphate with H2tmpyp4+ in the presence (A) and absence (B) of phosphate (50 p dm-3) at concentrations of 4.0 x rnol dm-3 H2tm yp4+, 7.5 x 16-4 rnol dm-3 ammonium molybdate and 0.2 rnol dm- F H2S04 440 460 480 500 Wn m Fig. 3 Change in intensity of li ht scattering at various concentra- tions of phosphorus as phosphate fpg dm-3): A, 0; B, 3.26; C, 6.52; D, 9.78; E, 13.0; and F, 16.3 The molybdophosphate rapidly reacts with the cationic porphyrin and causes Rayleigh scattering as shown in Fig.2. The intensity of light scattering is inversely proportional to the fourth power of the irradiated wavelength; however, H4tmpyp6+ has an absorption maximum at 447 nm (the so-called Soret band). Hence, the maximum intensity of light scattering was observed at 475 nm. If the intensities of the incident and scattered light (Rayleigh scattering) are denoted by I, and I, respectively, the Rayleigh scattering intensity is proportional to the concentration (c) and the relative mole- cular mass (M,) of the ion pair as shown by eqn. (2). where K is a constant that depends on the refractive index of the solution, the wavelength and the distance of the detector from the sample, and g(8) = 1 + cos28. Under the experimental conditions used here, the scattering intensity was detected at 8 = 90" on a spectrofluorimeter.Typical change in light scattering intensity is shown in Fig. 3 at concentrations of phosphorus as phosphate in the range 3.26-16.3 ppb. Composition of the Ion Pair The molar ratio method was applied at a constant concentra- tion of phosphorus as phosphate (16.3 pg dm-3). The results suggest the formation of a 1 : 1 complex between molybdo- phosphate and the cationic porphyrin. Effect of Concentration of Ammonium Molybdate The effect of the concentration of ammonium molybdate is shown in Fig. 4(a). The light scattering intensities of the ion pair and the reagent blank gradually increased with ammo- nium molybdate concentration in the range from 2.5 x 10-4 to 7.5 x 10-4 mol dm-3 and increased rapidly at concentrations >10 x 10-4 rnol dm-3.Effect of Concentration of Sulfuric Acid The effect of the concentration of sulfuric acid on the intensity of the ion pair and the reagent blank is shown in Fig. 4(b). The intensities of both the reagent blank and the ion pair decreased with the concentration of sulfuric acid. However, the intensity of the reagent blank reached a minimum and remained constant for a sulfuric acid concentration >0.2 mol dm-3. Hence the concentration of sulfuric acid was adjusted to 0.2 mol dm-3. Effect of Reaction Time The effect of the reaction time on the formation of molybdo- phosphate and its ion pair with H4tmpyp6+ was examined for reaction times from 2 to 10 min (Fig. 5 ) . Constant intensities of the light scattering were observed between 2 and 10 min after the addition of ammonium molybdate and H4tmpyp6+ to a sample solution containing phosphate.The ion pair forms rapidly and is stable. From the results presented above the optimum concentra- tions of the reagents are 7.75 x and 0.200 rnol dm-3 for ammonium molybdate and sulfuric acid, respectively. The concentration of sulfuric acid is very similar to that used for the determination of phosphate with molybdenum yellow.8 This suggests that the molybdophosphate compound formed is the same as that formed in the molybdenum yellow method. The molybdophosphate reacts with the cationic porphyrin and causes light scattering. It was expected that the ion pair would be stabilized by the addition of ethanol, which would lead to a decrease in the relative permittivity of the solution.However, ethanol increased the intensity of the light scattering of the ion pair and of the blank solution and no improvement was observed on the addition of ethanol. Calibration Graph and Sensitivity The calibration graph was linear in the range 3-100 pg dm-3 of phosphorus as phosphate with a correlation coefficient of 0.998. The relative standard deviation of the light scattering was 1.7% for 16.3 pg dm-3 of phosphorus.ANALYST, JULY 1992, VOL. 117 100 80 60 40 20 8 r O 1 * .- In a 4- c 80 60 40 20 0 0.1 0.2 0.3 0.4 [H2S041/mol dm-3 Fig. 4 Effects of the concentrations of ammonium molybdate (a) and sulfuric acid (b) on the intensity of light scattering in the absence (A) and presence (B) of 16.3 pg dm-3 of phosphorus as phosphate Effect of Foreign Ions The interference of some cations and anions usually encountered in natural water samples was studied for the determination of phosphate by the proposed method. No interference was observed even at 0.5 rnol dm-3 of chloride and 1 x 10-3 mol dm-3 of silicate.Magnesium and calcium ions at concentrations >0.1 mol dm-3 gave a negative error of 7% owing to complex formation with phosphate. Recommended Procedure for the Determination of Phosphorus as Phosphate Take 15 cm3 of a sample solution containing 3-100 pg dm-3 of phosphorus as phosphate in a 25 cm3 calibrated flask and add 3 cm3 of ammonium molybdate solution (6.25 x 10-3 rnol dm-3) containing 1.68 mol dm-3 sulfuric acid. Then add 1 cm3 of H2tmpyp4+ (1.00 X 10-4 mol dm-3) in order to form the ion pair of molybdophosphate with H4tmpyp6+ in acidic medium.The intensity of the light scattering is measured at 475 nm. (Both irradiation and measurement are carried out at this wavelength. ) Determination of Phosphate in Water Samples and Recovery Studies The proposed method was applied to the determination of phosphate in samples of tap and river water and also sea-water (from the Ariake Sea). The sample solutions were filtered through a 0.45 ym pore membrane filter and stored in a refrigerator. The results are presented in Table 1 together with the results of recovery studies. Phosphorus as phosphate at levels as low as 10 pg dm-3 was determined and the recovery was satisfactory. 1187 30 20 I 1 I 1 1 I 1 0 2 4 6 8 10 tlmin Fig.5 Effect of the reaction time on the formation of molybdo- phosphate (a) and its ion pair with H4tmpyp6+ (b) for the determina- tion of 16.3 pg dm-3 of phosphorus as phosphate by the proposed method Table 1 Determination of phosphorus as phosphate in sea-water and river water samples by the proposed method and results of recovery studies P-P043-/pg dm-3 Sample Added Sea-water 0 27 55 82 River water 0 27 55 82 Found 42 70 97 124 99 125 153 182 Correction for addition* 42 43 42 42 Mean: 42 99 98 98 100 Mean: 99 Tap water 0 11 11 27 36 9 55 63 8 82 91 9 Mean: 9 * i. e . , Phosphate concentration found minus phosphate concentra- tion added. Conclusion The application of light scattering to the determination of trace amounts of phosphate has been demonstrated. Light scattering originally lay in the domain of physicists and physical chemists, and the technique has been used to study solutions of macromolecules, including proteins, poly- saccharides, synthetic polymers, colloidal particles, micelles and micro-emulsions.9 However, analytical applications of light scattering spectroscopy will assume importance if a selective reaction, such as the formation of molybdophos- phate described here, is chosen.Several methods for the determination of trace amounts of phosphate in natural water samples have been reported; however, the proposed method is simple, sensitive and accurate and does not require any preconcentration such as solvent extraction,4.5 collection on a membrane filter6 and gel-phase absorption.' The sensitivity would be increased if an Ar laser were used.Further, the proposed method is applicable to flow injection owing to the fast reaction rate. A1188 ANALYST, JULY 1992, VOL. 117 flow analysis method using light scattering will be reported elsewhere. This work was supported in part by a Grant-in-Aid for Scientific Research (No. 0364098) and a Grant-in-Aid (No. 03231215) on the Priority Area of ‘Molecular Approaches to Non-equilibrium Processes in Solutions’ from the Ministry of Education, Science and Culture, Japan. We also thank the Ito Science Foundation for its support. References 1 Tabata, M., and Tanaka, M., TrAC, Trends Anal. Chem. (Pers. Ed.), 1991, 10, 128. 2 Fiel, R. F., J. Biomol. Struc. Dynam., 1989, 6 , 1259. 3 Tabata, M., Sakai, M., Yoshioka, K . , and Kodama, H., Anal. Sci., 1990, 6 , 651. 4 Motomizu, S., Wakimoto, T., and Toei, K., Talanta, 1984,31, 235. 5 Nasu, T., and Minami, H., Analyst, 1989, 114,955. 6 Kan, M., Nasu, T., and Taga, M., Anal. Sci., 1991,7, 87. 7 Yoshimura, K., Nawata, S., and Kura, G., Analyst, 1990, 115, 843. 8 Boltz, D. F., and Mellon, M. G., Anal. Chem., 1948, 20, 749. 9 Schmitz, K. S., An Introduction to Dynamic Light Scattering by Macromolecules, Academic Press, New York, 1990. Paper llO6505J Received December 30, 1991 Accepted January 10, 1992

ISSN:0003-2654    

DOI:10.1039/AN9921701185

出版商:RSC    

年代:1992

数据来源: RSC

摘要:

ANALYST, JULY 1992, VOL. 117 1189 Spectrofluorimetric Determination of Boron in Soils, Plants and Natural Waters With Alizarin Red S Ana M. Garcia Campana, Fermin Ales Barrero and Manuel Roman Ceba* Department of Analytical Chemistry, Faculty of Sciences, University of Granada, 18071 Granada, Spain A simple and sensitive spectrofluorimetric method for the determination of boron with Alizarin Red S is described. The fluorescence intensity of the complex formed in aqueous solution develops immediately and heating is not required. The excitation and emission wavelengths are 465 and 615 nm, respectively. The detection limit is 7.2 ng cm-3. A study was made of the influence of several ions as potential interferents. The method was applied satisfactorily to the determination of boron in soils, plants and natural waters.Keywords: Boron determination; Alizarin Red S; spectro fluorimetry; environmental samples There is increasing interest in the determination of boron in several fields; for example, boron is an essential trace element in the physiology of plants.' Among the methods used for the determination of boron, fluorescence methods show the greatest sensitivity, with detection limits at the nanogram level. However, these methods are not highly selective. Some, such as those based on benzoin2 and m0rin3 complexes, involve the previous distillation of boron as methyl borate, to isolate it from interfering species. Other methods eliminate numerous inter- ferents by use of ion-exchange resins or by extraction, such as those using butyl-Rhodamine B plus fluoride ions,4.5 diben- zoylmethane,6-8 Rhodamine 6G plus salicylic acid9210 and 2,6-dihydroxybenzoic acid plus rivanol.11 Many of the proposed spectrofluorimetric methods for the determination of boron are characterized by reactions carried out in concentrated sulfuric acid. In addition, some of these methods require prior heating of the samples or a prolonged period of time to complete the reaction. A further difficulty is the need to work with corrosive media such as concentrated sulfuric acid. Boron forms fluorescent compounds in such a medium with dibenzoylmethane,6--8 2-hydroxy-4-methoxy-4'-chlorobenzo- phenone,12 Thoron 1,13,14 resacetophenone,15-17 2,4-dihy- droxybenzophenone ,18-20 salicyclic acid ,21J2 acetylsalicylic acid23 and some anthraquinone derivatives, such as carminic acid,24,25 quinizarin26 and quinizarin-2-sulfonic acid.27 Alizarin Red S (the sodium salt of 1,2-dihydroxyanthraqui- none-3-sulfonic acid) was first proposed28 in 1936 as a fluorescence reagent for the identification of boric acid in concentrated sulfuric acid.In the present work, a method for the determination of boron with Alizarin Red S is described. The method is very simple because the reaction is carried out in aqueous solution and the fluorescence develops imme- diately. The detection limit is 7.2 ng cm-3. The method was applied satisfactorily to the determination of boron in soils, plants and natural waters. Experimental Apparatus All spectrofluorimetric measurements were performed on a Perkin-Elmer MPF-43 fluorescence spectrophotometer, equipped with an Osram BO 150 W xenon lamp, excitation and emission grating monochromators, 1.0 X 1.0 cm quartz cells, an R-508 photomultiplier and a Perkin-Elmer 023 recorder.A standard fluorescent stick (equivalent to a 3 x 10-4 rnol dm-3 solution of Rhodamine B) gave a scale reading * To whom correspondence should be addressed. of 43 units, with the following parameters: sensitivity, 1 coarse and 1 fine; slit-widths, 5 nm for excitation and 3 nm for emission; temperature, 20 "C; excitation wavelength, 480 nm; and emission wavelength, 580 nm. The fluorescence spectra are given without spectral correction. Spectrophotometric measurements were performed on a Perkin-Elmer Lambda 5 ultraviolet/visible spectrophotometer with 1.0 X 1.0 cm quartz cells.A Crison Digit-501 pH meter was used for all pH measurements. Reagents All experiments were performed with analytical-reagent grade chemicals using doubly distilled water. Stock boric acid solution, 0.100 g dm-3 of boron. Prepared by weighing exactly 0.5715 g of pure H3B03 (Merck) and diluting to 1 dm3 with doubly distilled water. The solution was stored in a polyethylene bottle. Alizarin Red S solution, 1.0 x 10-3 mol dm-3. Prepared by weighing exactly 0.171 g of the reagent (Carlo Erba) and diluting to 500 cm3 with doubly distilled water. Buffer solution (PH 7.4). Prepared by mixing 0.1 mol dm-3 disodium hydrogen phosphate with 0.1 mol dm-3 potassium dihydrogen phosphate. Procedure for the Determination of Boron Into a 10 cm3 calibrated flask, transfer a suitable aliquot containing 0.25-10 pg of B"'.Add 1 cm3 of buffer solution, 1.5 cm3 of 1 x 10-3 mol dm-3 Alizarin Red S and dilute to the mark with doubly distilled water. Measure the fluorescence intensity at 615 nm, with excitation at 465 nm, against a reagent blank prepared in a similar way but without boron. Owing to the influence of temperature, it is necessary to maintain the temperature at 25 "C by means of a thermostat. Recommended Procedure for the Determination of Boron in Environmental Samples Soil samples Weigh exactly 30 g of finely ground soil sample and transfer it into a 125 cm3 Florence flask. Add 60 cm3 of doubly distilled water and heat under reflux for 5 min. Allow the mixture to cool and then filter under suction. Use aliquots of no more than 2 cm3 and add 1 cm3 of 0.1 mol dm-3 ethylenediamine- tetraacetic acid (EDTA) solution.Establish the calibration graph in the presence of this concentration of EDTA for the determination of boron by the recommended procedure.1190 ANALYST, JULY 1992. VOL. 117 Plant samples Weigh exactly 1 g of plant sample, after pulverizing and drying it at 60 "C. Ash the sample in a muffle furnace at 500 "C for 2 h and then leave it to cool inside the furnace. Humidify the ashes with doubly distilled water, add 1 cm3 of concentrated hydrochloric acid and heat at 70 "C on a hot-plate. Filter and wash with hot water. Add 5 cm3 of 0.1 mol dm-3 EDTA solution. Neutralize with sodium hydroxide solution, transfer into a 25 cm3 calibrated flask and dilute to the mark with doubly distilled water.Use aliquots of not more than 5 cm3 for the determination of boron with Alizarin Red S by the procedure described above for soil samples. Natural water samples After filtering the sample, take aliquots of not more than 5 cm3, add 1 cm3 of 0.1 mol dm-3 EDTA solution and follow the procedure described above for soil samples. Results and Discussion Spectral Characteristics The fluorescence excitation and emission spectra of the boron-Alizarin Red S complex and of the reagent blank are shown in Fig. 1. The fluorescent species has excitation and emission maxima at 465 and 615 nm, respectively. Effect of pH The pH of the medium had a large effect on the fluorescence intensity. Experiments indicated that the optimum pH range for complex formation was 6.7-8.0.The fluorescence de- creased markedly at both lower and higher pH values. A disodium hydrogen phosphate-potassium dihydrogen phos- phate buffer of pH 7.4 was selected. Stability, Effect of Temperature and Order of Addition of Reagents The fluorescence intensity of the boron-Alizarin Red S complex developed instantaneously and remained almost constant for 5 h after sample preparation. The effect of temperature on the measurements was studied by heating thermostatically a series of samples to between 5 and 50°C. An increase in temperature from 5 to 50°C reduced the fluorescence intensity by 1.8% "C-1; it was found necessary to maintain the temperature at 25 "C. The order of addition of the reagents was investigated and was found to have no effect on the fluorescence intensity, 60 I 1 I I I I 1 350 430 510 590 670 750 ktnm Fig.1 Fluorescence excitation (Aern = 615 nm) and emission spectra (hex = 465 nm) of the boron-Alizarin Red S complex (A and B) and of the reagent blank (A' and B') Influence of Reagent Concentration The effect of reagent concentration on the fluorescence intensity for solutions containing 8 x 10-5 mol dm-3 of boron was studied. The fluorescence intensity increased with the reagent concentration up to 1.12 x 10-4 mol dm-3, then remained constant between 1.12 x 10-4 and 2.0 x 10-4 mol dm-3, the last being the highest concentration studied. A 1.5 X 10-4 mol dm-3 reagent concentration was selected to ensure a sufficient excess of the reagent. The stoichiometry of the complex was studied under the established conditions by the classical method of Yoe and Jones.29 From this study it was concluded that the composition of the complex was 1 : 1.This result is concordant with that obtained by a potentiometric method.30 Analytical Characteristics Under the optimum operating conditions selected, there was a linear relationship between fluorescence intensity and BIII concentration in the range 25.0-1000 ng cm-3. The precision of the method was studied by the analysis of solutions containing known amounts of BIII. The results from the determination of 100 ng cm-3 of BIII showed a standard deviation of 4.0 ng cm-3 and a relative error of 3.5%. The detection limit, defined as the analyte concentration leading to a fluorescence intensity that is three times the standard deviation of the blank,31732 was 7.2 ng cm-3.Influence of Foreign Ions In order to assess the possible analytical applications of this fluorescence reaction, the effect of a number of foreign ions was studied by carrying out determinations of 100 ng cm-3 of boron in the presence of each of these ions. An interferent to boron ratio of 1000 ( d m ) was tested, and, if interference occurred, the ratio was progressively reduced until interfer- ence ceased. The criterion for an interference was a fluores- cence intensity value varying by more than 5% from the expected value for boron alone. As most of the ions tested were found to interfere with the measurement of fluorescence intensity and as the tolerance level for many metal ions was increased by the addition of EDTA solution as a masking agent, the influence of interfer- ents was studied in the presence of an EDTA concentration of 0.01 mol dm-3.The largest interferences were found for MoV1, Wvl, Sn'", Sb"' and Be", which increased the fluores- cence intensity (see Table 1). Determination of Boron in Environmental Samples The results of the determination of boron in soils are shown in Table 2. Soil samples were provided by the Department of Edaphology (Faculty of Sciences, University of Granada) and Table 1 Interferences in the presence of EDTA as masking agent (concentration of BIII, 100 ng cm-3) Ratio of ion BIII (dm) Foreign ion lo00 Li', Nal, K1, Rb', Cs', Ca", Sr", Mn", Ni", Ag', Zn", Cd", Hgll, Tll, Pb", AsV, SeIV, Vv, Si032-, N03-, NO2-, P043-, S042-, F-, Cl-, Br-, I-, C2042- 300 100 Ball, Crlll Cult, T l r 1 I , Mg", Pd" , Int1' 50 Fel", Co", All1' 20 Y1ll, CeIV, Tilv 10 Bi"' 1 MeV' 0.3 Wvl, SnIv, Sb"l 0.05 Be"ANALYST, JULY 1992, VOL.117 1191 3 4 Tkacz, W., and Pszonicki, L., Anal. Chim. Acta, 1977,90,339. Babko, A. K., and Chalaya, Z. I., Ukr. Khim. Zh., 1964,30, 268. Babko, A. K., Chalaya, Z. I., and Voronova, E. D., Zavod. Lab., 1965,31, 157. Marcantonatos, M., Gamba, G., and Monnier, D., Helv. Chim. Acta, 1969, 52, 538. Skorko-Trybula, Z . , and Boguszewska, Z . , Mikrochim. Acta, Part I I , 1976, 235. Aznarez, J., Bonilla, A., and Vidal, J. C., Analyst, 1983, 108, 368. Babko, A. K., andvasilevskaya, A. E., Ukr. Khim. Zh., 1967, 33, 314. Vasilevskaya, A. E., Nauchn. Tr. Vses. Inst. Min. Resur., 1971, 5,22.Sanchez-Pedreiio, C., Hernandez Cordoba, M., and Lopez Garcia, I., An. Quim., 1984, 80, 253. Liebich, B., Monnier, D., and Marcantonatos, A., Anal. Chim. Acta, 1970, 52, 305. Marcantonatos, M., Monnier, D., and Marcantonatos, A., Helv. Chim. Acta, 1964,47, 705. Rigin, V., and Melnickenko, N., Zavod. Lab., 1967, 33, 3. Raju, N., and Rao, G., Nature (London), 1954, 174,400. Raju, N. A., and Neellakantum, K., Curr. Sci., 1958, 27, 432. Rao, G. G., and Raju, N. A., Fresenius' Z. Anal. Chem., 1969, 167, 325. Monnier, D., Marcantonatos, A., and Marcantonatos, M., Helv. Chim. Acta, 1964,47, 1980. Kristalev, P. V., and Shevchenko, Ya. F., Sb. Nauchn. Tr. Permsk. Politekh. Inst., 1979, 71, 38. Kristalev, P. V., and Chelnokova, M. N., Zh. Anal. Khim., 1974, 29, 1650.Shibazaki, T., Bunseki Kagaku, 1963, 12,385. Shibazaki, T., Yakugaku Zasshi, 1968, 88, 1393. Podchainova, V. N., Skornyakova, L. V., and Dvinyanivov, B. L., i z v . Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol, 1968, 11, 241. Bruce, T., and Ashley, R. W., Report of the Atomic Energy Commission of Canada, AECL-4446, 1973; Nucl. Sci. Abstr., 1973, 28, 50. Gabriels, R., and van Keirsbulck, W., Lab. Pract., 1977, 26, 620. Holme, A., Acta Chem. Scand., 1967, 21, 1679. Salinas, F., Muiioz de la Peiia, A., Murillo, J. A., and JimCnez Shnchez, J. C., Analyst, 1987, 112, 913. Szebellady, L., and Tomay, S., 2. Anal. Chem., 1936, 107,26. Yoe, J. H., and Jones, A. L., Ind. Eng. Chem., Anal. Ed., 1944, 16, 111. Havelkova, L., and Bartnesk, M., Collect. Czech. Chem. Commun., 1968, 33, 385.Nomenclature, Symbols, Units and Their Usage in Spectro- chemical Analysis 11, Spectrochim. Acta, Part B , 1978,33,242. Guidelines for Data Acquisition and Data Quality Evaluation in Environmental Chemistry, Anal. Chem., 1980, 52, 2242. Lachica, M., in 4th International Colloquium on the Control of Plant Nutrition, ed. Cottenie, A., Rijksuniversiteit Labora- torium voor Analytische en Agrochemie, Gent, 1976, vol. 11, pp. 53-61. Table 2 Results of the determination of boron in soils Amount of BII1 found/pg ~ m - ~ Relative Spect rophoto- standard metric Proposed deviation Sample method* method (70 1 A 3.05 3.33 4.11 B 2.45 2.67 5.38 C 2.82 2.72 4.73 * Using azomethine-H (ref. 33). 5 6 7 8 9 10 Table 3 Results of the determination of boron in plants 11 Amount of BtI1 found/p.g ~ m - ~ Relative Spectrophoto- standard metric Proposed deviation Sample method* method (Yo) Oak-tree leaves 35.3 33.9 3.6 Carnation leaves 73.0 71.2 2.6 * Using azomethine-H (ref.33). 12 13 14 15 16 17 Table 4 Results of the determination of boron in natural waters 18 B111 added BIIt found*/ Recovery Origin of sample ng (3131-3 ng cm-3 (Yo) 19 Juncarfl rivulet - 100 200 300 Genil river - 50 100 150 79.6 - 177.9 97.7 279.8 100.3 378.4 98.5 20.1 - 69.2 95.6 119.7 98.0 170.0 99.5 20 21 22 23 24 * Mean of four determinations. 25 were collected from the Andarax valley (Almeria, Spain). Sample A was taken from uncultivated ground and samples B and C were from orange groves. The results of the determination of boron in plant samples by the recommended procedure are shown in Table 3. The determination was also carried out by the azomethine-H method33 for comparison. The results obtained are concor- dant, but the proposed method is more sensitive and easier to perform. The proposed method was also applied to the determination of boron in natural waters from the province of Granada (Spain). The results are shown in Table 4. In order to detect any losses of boron, the standard additions method was used. 26 27 28 29 30 31 32 33 References 1 2 Bonner, J., and Varner, J. E., Plant Biochemistry, Academic Press, New York, 1975. Parker, C. A., and Barnes, W. J., Analyst, 1960, 85,828. Paper 110.58750 Received November 19, 1991 Accepted February 3, 1992

ISSN:0003-2654    

DOI:10.1039/AN9921701189

出版商:RSC    

年代:1992

数据来源: RSC

摘要:

ANALYST, JULY 1992, VOL. 117 1193 Mobility of Superficially Applied Caesium-134 and Strontium-85 in Apple Branches Under Precipitation-free Conditions* Gunnar B. Bengtsson MATFORSK, Norwegian Food Research Institute, Osloveien 1, N- 1430 /Is, Norway The recovery of superficially applied 134Cs+ and 85Sr2+ in apple branches protected from precipitation decreased with time. Translocation of 134Cs to uncontaminated branches declined rapidly with the distance from the contaminated branches. Extensive translocation of 134Cs from foliage to fruits occurred within the same branch: after 84 d, 50% of the recovered activity was found in fruits and most of it in the edible part (excluding peel). On the other hand, 85Sr was less mobile and in virtually all fruit 85Sr was in the peel. Rinsing leaves removed 30% of both radionuclides 1 d after contamination and decreasing fractions later on.Rinsing fruits removed up to 62% of the peel radionuclides. Further rinses and washes (plus detergent) of fruits showed that 134Cs had the same distribution in the outer skin as85Sr and that the ratio of the two nuclides was close to the ratio in the contamination solution. This indicates that apple skin is a barrier not only to 85Sr, but probably also to 134Cs. Unaccounted for disappearance of radioactivity from fruits and leaves could have been a result of field losses of small superficial particles. Keywords: Fruit; direct radioactive contamination; radionuclides; translocation; radioactive decontamination During a radioactive fallout, direct deposition is the dominant route of contamination of growing plants instead of by root uptake. The nature of the deposited material, together with many other factors, determines the extent of retention on the exposed parts.1'2 Removal by rain was found to be the main cause of losses of soluble substances.3.4 Nevertheless, the foliar uptake of superficial radionuclides can be a very rapid process.5-8 The further transport in the plant differs greatly between elements, e.g., caesium spreads readily, whereas strontium has a relatively low mobility.3~9~10 The time of the year when contamination occurs is also important for the extent of transfer to human foods.This aspect has been termed 'seasonality' by Aarkrogll and has been thoroughly examined in cereals, e.g., in refs.9 and 12. Only one experimental study on seasonality in fruit trees has been found.10 In addition, the Chernobyl fallout early in the season of 1986 initiated several studies on various fruit trees,13-16 but these dealt mainly with long-term behaviour of radiocaesium. Contamination by root uptake was found to be of minor importance in comparison with foliar uptake. During the following years, the radiocaesium in new tree products (fruits, leaves and shoots) was almost exclusively derived from the woody parts after retraction from the leaves of the first year. Although certain areas of Norway were contaminated by the Chernobyl fallout in 1986, the main fruit-growing districts received relatively low levels of radionuclides. 'Also, at the time of fallout around May 1, the leaves or blossoms had not emerged and, therefore, internal contamination of fruits was negligible. In the present study, the recovery and distribution of 134Cs and 85Sr was investigated at normal harvest time in apple branches sheltered from precipitation after direct application of the radionuclides on three different occasions in the same year (1989).The effects of rinsing and washing after harvest were also studied. Experimental Field Treatment Nineteen year old apple trees (Malus domestica, var. aroma) in an orchard 30 km south of Oslo were used. Pesticide * Presented at the XXVII Colloquium Spectroscopicum Inter- nationale (CSI) Pre-Symposium on Measurements of Radionuclides after the Chernobyl Accident, Bergen, Norway, June 6-8, 1991. treatment had been restrictive and was discontinued prior to the experiment.About 4 cm3 of an aqueous tracer solution of 34CsC1 + 85SrC12 (each 92.5 kBq cm-3 on July 1, Nos. CCS 1 and SOS 3, respectively; Amersham, UK), adjusted to pH 6.0 with dilute NaOH, were applied from above as very fine droplets with an all-glass spraying apparatus on approximately 1.4 m branches of the same tree. Correction was effected for activity sorbed onto the surfaces of the spraying apparatus. The spraying was carried out through holes in a polyethylene bag wrapped around each branch, collecting droplets not hitting the branch. About 70% of the activity was captured by the branches. Five minutes after spraying, the polyethylene bag was replaced by a bag made of thin polypropylene fibre (transparent to light and gases) to give protection against animals and being a collector of any radioactive material falling off.Half of the tree was covered 3 m above ground by 3 m x 4 m x 0.18 mm of garden house plastic (ethylene-vinyl acetate copolymer) supported by a metal cage. This, together with polypropylene fibre sheets on the upper 1.5 m of the cage walls, was an effective precipitation shelter, although other- wise providing close to natural conditions. Three branches were contaminated: (i) on July 4, when the foliage area was assumed to be maximum and the mass of the green fruits was about 8.4 g (R, n = 23), diameter 2.8 cm; (ii) on August 16, when the fruits were about 46.5 g (R, n = 15), diameter 5.1 cm; and (iii) on October 3. The two first branches were harvested on September 26, and the third on October 4.They were brought to the laboratory and partitioned into leaves, fruits and woody parts within 1 h. The biomass was 1985,1296 and 1959 g and that of fruits was 1674 g (3 = 57.9 g, n = 26), 949 g (R = 52.0 g, n = 15) and 1621 g (R = 73.7 g, n = 22) for the three branches, respectively. A control branch on the same tree (sheltered) and one on another tree (unshel- tered) were sprayed on July 4 with distilled water, but otherwise treated as for the branch contaminated on the same day [biomass 3143 and 2739 g, of which fruits were 2596 g (R = 70.2 g, n = 37) and 2276 g (X = 71.1 g, n = 32), respectively]. The biomass of the foliage and the woody parts was about the same. The leaves were stored overnight and the fruits for 14-24 d, in both instances in open plastic bags at 4 "C in the dark.Rinsing and Washing The leaves were rinsed in 500 g of tap-water, 17 "C, for 1 min in a polyethylene bag by turning the bag each second. The water1194 ANALYST, JULY 1992, VOL. 117 (about 400 g) was drained off over a period of 1 min. Intact fruits were rinsed three times in the same manner, with a water-to-fruit mass ratio of 0.7 : 1, followed by three similar treatments (washes) with water containing 0.1% m/m of ordinary household detergent solution (‘Sunlight’, Lilleborg fabrikker, Oslo, Norway) with a fluid-to-fruit ratio of 0.4 : 1, and a final rinse in water (ratio 0.7 : 1). Results were corrected as if the fluids were quantitatively drained off in each step. The water was decalcified before entering the tap-water system of the laboratory building.Analyses Treatment fluids, rinsed leaves, woody parts, the edible part (68% of fruit mass), peel (23%) and core plus stalk (9%) of fruits were freeze-dried and transferred directly or by means of 0.5 mol dm-3 HN03 into 20 cm3 plastic vials and counted by gamma spectrometry [Li(Tl) detector, Minaxi Auto-Gamma 5000 counter; Packard, Downers Groove, IL, USA]. The spill-over was 1% from the *5Sr to the 134Cs window and 19% vice versa. The data were corrected for spill-over and radioactive decay. Activity concentrations were derived from duplicate analyses of homogenized samples. The mean relative standard deviation (RSD) of the duplicates from solid samples was 3.6% for 134Cs and 8.0% for 85Sr.For the duplicates of fluid samples, the mean RSD was 22 and 31%, respectively. The latter variations included a large component resulting from uneven spray contamination of fruits and leaves on the same branch. (This error is, however, circumvented by the fractional mode of expressing the results in Tables 4 and 5 . ) Results Recovery The recovery of applied activity in branches decreased with time (Table 1). Table 1 Recovery of radionuclides in contaminated branches (YO) Time after sprayindd 1 41 84 134cs 92 84 69 85Sr 80 72 57 Distribution of Radionuclides in Contaminated Branches There was a marked decrease of 85Sr in the fruits, while about 90% of the recovered 85Sr was in the leaves, irrespective of the time between spraying and harvest (Table 2). For 134Cs, a redistribution was evident: the leaf fraction was more than halved and the fruit fraction increased from 5 to 50% at 1 and 84 d after spraying, respectively.An increase in the woody parts seems to have occurred for 134Cs. Distribution of Radionuclides in Fruits Almost all the 85Sr activity in fruits was in the peel, irrespective of time after spraying branches, whereas a high peeling fraction of 134Cs, 1 d after spraying, decreased considerably even after only 41 d (Table 3). The distribution after 41 and 84 d was very similar and agreed with the distribution in non-sprayed branches having received 134Cs by translocation (data not shown). Effect of Rinsing Leaves Rinsing the leaves in water released about 30% of both 85Sr and 134Cs, 1 d after contamination. Thereafter, smaller and decreasing fractions were released (Table 4).Effect of Rinsing and Washing Fruits One day after spraying, about 60% of both 85Sr and 134Cs in the peel could be rinsed off the fruits. Two further rinses released much smaller fractions (Table 5). Addition of detergent had a positive effect, but three consecutive washes did not release more than about 10% of the peel activities (treatment Nos. 4-6). On the other hand, when contamination had been carried out 41 or 84 d before harvest, the pattern differed greatly between the two nuclides: only the 134Cs release decreased with time. For 85Sr, high fractions were released throughout the experiment. Including a final rinse in water, all seven cycles released virtually all of the nuclide after 84 d.However, the detergent effect was similar for both radionuclides. This increased with time after contamination: after 84 d about the same amounts were released during the three washes as during the first three rinses. The total activities of released *5Sr and 134Cs were comparable (last column of Table 5). ~ ~~~~~ Table 2 Distribution of radionuclides in contaminated branches (% ) 134cs 85Sr Time after Woody Woody sprayindd Fruits Leaves parts Fruits Leaves parts 1 5.3 90.7 4.0 6.4 89.8 3.8 41 24.8 62.9 12.3 1.9 94.6 3.5 84 50.0 39.5 10.5 0.31 92.5 7.2 Table 3 Distribution of radionuclides in fruits (YO) 134cs 8% Time after Core Core branchedd part Peel* stalk? part Peel* stalk? spraying Edible plus Edible plus 1 13.4 83.1 3.5 0 97.2 2.8 41 53.8 33.1 13.1 0 100 =O 84 58.5 28.8 12.7 0 100 -0 * The activity released by rinsing and washing whole fruits is included.t Any activity released by rinsing and washing whole fruits is not included.ANALYST, JULY 1992, VOL. 117 1195 Translocation of 1MCs Between Branches An indication of active translocation was that the activity concentration of 134Cs was elevated in organs of untreated branches in the vicinity of the contaminated branches (Table 6 and Fig. 1). There was a declining trend with distance seen for branch Nos. 3-6, which were situated proximal to the contaminated branch No. 2. In branch No. 7, which was a collateral to branch No. 1, the activities were not elevated. Background levels are represented by branches No. 8 (about 4 m away from any spray-contaminated branch) and No. 9 (from another tree).In branches not sprayed with radio- nuclides, the activity fractions removed by rinsing or washing were small and insignificant in comparison with remaining activities (data not shown). Discussion The results show that a considerable redistribution of 134Cs can occur under precipitation-free conditions in apple branches after direct contamination. On the other hand, 85Sr remained largely in the foliage, hence corroborating the low mobility of strontium isotopes found in other species after direct application.3~9~10 The behaviour of 134Cs and *%r during rinsing of the leaves indicates, however, that the uptake was rapid and similar for Table 4 Released fractions of radionuclides in leaves on rinsing (YO) Time after spraying branchedd 1 41 84 134Cs 30.2 7.6 4.0 85Sr 28.6 11.4 2.2 the two radionuclides.It was probably enhanced by the humidity of the air, because the shelter prevented moisture by rain or dew. The nightly relative humidity is usually 100% during the Norwegian growing season. The stimulating effect of high humidity has been shown for young barley leaves under laboratory conditions.6 Hence, precipitation-free periods in the Norwegian climate do not signify that fallout contamination would stay superficial and, therefore, remain relatively harmless. Nevertheless, the contamination would be maximum, because of the absence of removal by rainfall. In comparison, open-field orange leaves lost half of their radiostrontium and most of their radiocaesium, after rainfall and sprinkle-type irrigation, between 5 and 55 d after contamination.10 The decreasing recovery with time of radionuclides in the spray-contaminated branches can only be explained, in part, by translocation. The unaccounted for losses could have been due to the disappearance of small superficial particles through the fibre plastic bag. Spontaneous shedding of plant particles can occur under dry conditions,17 but wind erosion should also be a contributing factor. The large accumulation of 134Cs in fruits is in accordance with a high rate of translocation from the foliage. The same type of translocation has been observed in several species of fruit trees after the Chernobyl fallout13914 and in an experimentally contaminated orange branch. 10 In the present study, as much as 29% of the recovered 134Cs was in the edible part (excluding peel) of the fruits after 84 d, i.e., 20% of the applied activity.At this time, the activity concentration of 134Cs in (washed) fruits was one-third of that in (rinsed) leaves on a dry mass basis. This is consistent with the distribution of 137Cs in Mediterranean apple trees 2 months or more after contamination of the green leaves by the Chernobyl fallout.13 Table 5 Released fractions (YO) of peel radionuclides by sequential rinsing and washing whole fruits* Treatment No. 1 2 3 4 5 6 Time branchesld after spraying Rinses Washes 134cs- 1 61.6 2.92 1.48 3.69 3.58 2.65 41 7.18 0.77 0.39 1.02 0.73 0.45 84 0.39 0.14 0.069 0.40 0.16 0.13 1 55.2 5.0 2.0 5.2 3.8 2.1 41 59.4 7.9 3.5 7.2 4.3 2.1 84 35.1 8.0 4.1 35.4 8.0 7.6 85Sr- * Each treatment was 1 min in water (rinse) or water + detergent (wash).t Numbers in parentheses indicate fractions of applied activity on branch (YO). 7 Rinse Totalt 0.68 76.6 (3.1) 0.20 10.7 (0.55) 0.052 1.34 (0.12) 0.62 73.9 (3.7) 1.2 85.5 (0.76) 2.0 100.0 (0.17) Table 6 Translocation of 134Cs between branches Distance inside tree from branchkm Branch Fruits (after Leaves Woody No. Treatment No. 1 No. 2 rinses + washes) (after rinse) parts Activity ConcentratiordBq g-l dry mass Contaminated 41 d before harvest Contaminated 84 d before harvest Untreated Untreated Untreated Untreated Sprayed with distilled water Untreated, outside shelter On other tree: sprayed with distilled water - 390 390 - 380 10 370 20 390 40 393 43 45 400 380 430 204 434 22.8* 7.4 1.7* 1.1* BDt BD BD 1283 1272 23.3 9.8 5.5 3.4 0.3 0.4 0.6 158 235 19.6 3.9 2.9 2.0 0.2 0.2 0.1 * Untreated.t BD = Below detection limit.1196 ANALYST, JULY 1992, VOL. 117 Fig. 1 Outline of translocation experiment. Branch Nos. 1-8 (large numerals) were harvested on September 26,1989. Branch Nos. 1 and 2 were s ray-contaminated 41 and 84 d before harvest, respectively. The translocation distances for l34Cs in centimetres are given in small numerals. k r o w s symbolize the bases of branches that are not depicted. The shaded area indicates the part of the tree exposed to precipitation. The remainder of the tree was encaged and sheltered by plastic sheets. Results are given in Table 6 The absence of detectable transfer of 85Sr to the interior of fruits is in agreement with a low mobility of strontium in plants after direct contamination.Unaccounted for losses seem to have occurred from the outer surfaces of the fruits, because the remaining activity of 85Sr would have been higher if the fruit area exposed to spraying had been taken into account. Surprisingly, an increased total fraction of 85Sr, with time after contamination, was released in the peeling, although the single releases among the rinses and washes pointed to a deeper distribution. The fruit skin was obviously a barrier to direct uptake of 85Sr, which was otherwise readily absorbed by leaves. The release of 134Cs from fruits into the rinsing and washing fluids paralleled the behaviour of 85Sr. This indicates that the two radionuclides had the same distribution in the outer layers of the apple skin.Some penetration of 134Cs through the fruit skin cannot be excluded. It is, however, unlikely that this had a rate similar to the unaccounted for (field) losses of 85Sr, and at the same time it did not disturb the similar ratio of the two nuclides in the consecutive treatment fluids. Therefore, most of the 134Cs in the pith-like layer of the peeling inside the skin must have been translocated from the leaves. This layer, being the extension of the edible part, occupied most of the peeling, which, in the present study, was up to 3 mm thick. The practical consequences in a fallout situation would be that countermeasures in the first year should mainly aim at reduction of radiocaesium transfer via the woody parts to the fruits of subsequent years.Therefore, rinsing should be of limited importance in comparison with removal of the foliage. If the foliage is collected, contamination of the surroundings is also reduced. Fruits of the first year could be utilized if they are treated for superficial contamination (washing/peeling), but, for fallout with soluble radiocaesium, immediate harvest is necessary. The technical assistance from Anne Birgit Baevre and Viggo Foss is gratefully appreciated. The author also thanks the following persons at the Agricultural University of Norway: Georg @stby and Helge Lien at the Isotope Laboratory for technical assistance, and Finn Miige, at the Section of Fruits and Berries, for providing experimental trees and for valuable discussions. References 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Russel, R.S., in Radioactivity and Human Diet, ed. Russel, R. S., Pergamon Press, Oxford, 1966, pp. 87-104. Miller, C. W., and Hoffman, F. O., Health Phys., 1983,45,731. Middleton, L. J., Int. J. Radiat. Biol., 1959, 4, 387. Kirchmann, R., Fagniart, E., and van Puymbroeck, S., in Radioecological Concentration Processes, eds. Aberg , B . , and Hungate, F. P., Pergamon Press, Oxford, 1967, pp. 475483. Bukovac, M. J., and Wittwer, S. H., Plant Physiol., 1957, 32, 428. Middleton, L. J., and Sanderson, J., J. Exp. Bot., 1965,16,197. Levi, E., Physiol. Plant., 1970, 23, 811. Oestling, O., Kopp, P., and Burkart, W., Radiat. Phys. Chem., 1989,33, 551. Aarkrog, A., Health Phys., 1975, 28,557. Delmas, J., Bovard, P., Grauby, A., Disdier, R., Blondel, L., and Guennelon, R., in International Symposium on Radioecol- ogy Applied to the Protection of Man and his Environment, Rome, September 7-10,1971, ed. Coppe, A., Commission of the European Communities, pp. 1081-1101. Aarkrog, A., Analyst, 1992, 117,497. Aarkrog, A., and Lippert, J., Radiat. Bot., 1971, 11,463. Baldini, E., Bettoli, M. G., and Tubertini, O., Adv. Hortic. Sci., 1987, 1, 77. Monte, L., Quaggia, S., Pompei, F., and Fratarcangeli, S., J. Environ. Radioact., 1990, 11, 207. Antonopoulos-Domis, M., Clouvas, A., and Gagianas, A., Health Phys., 1990, 58, 737. Antonopoulos-Domis, M., Clouvas, A., and Gagianas, A., Health Phys., 1991, 61,837. Moorby, J., and Squire, H. M., Radiat. Bot., 1963, 3, 163. Paper 1/0451 OE Received August 29, 1991 Accepted February 27, 1992

ISSN:0003-2654    

DOI:10.1039/AN9921701193

出版商:RSC    

年代:1992

数据来源: RSC

摘要:

ANALYST, JULY 1992, VOL. 117 1197 Quantitative Trace Analysis of Biological Materials Principles and Methods for Determination of Trace Elements and Trace Amounts of some Macro Elements Edited by Hugh A. McKenzie and Lloyd E. Smythe. Pp. xiv + 791. Elsevier. 1988. Price $289.00; Df1550.00. ISBN 0-444-80958-9. The editors and publishers of this book state, in the preface, that their aim has been to provide a comprehensive, conve- nient text dealing with the broad range of quantitative analysis of biological materials. To achieve this end, 43 chapters and 2 appendices have been written and presented as 12 sub- divisions. The first 3 chapters are by the editors and, as Part 1, form an introduction to general aspects of trace analysis. Emphasis has been placed on the importance of well thought out sampling and quality assurance procedures.Good, practical advice is given on designing new clean laboratories and up-grading existing facilities. Chromatographic, spectroscopic, electrochemical and radiochemical methods for the trace determination of ele- ments are covered in Parts 2-5. Contributions have been made to these sections and to the rest of the book by authors from Australia, Europe and North America. In addition to describ- ing the theory behind each technique and detailing the instrumentation, examples of applications and required sample preparation are given. The relatively recent develop- ment of inductively coupled plasma mass spectrometry is mentioned but not detailed and the same applies to the use of microwave dissolution of samples.In Part 6, automated methods and data handling are reviewed. In their introductory chapters, the editors stress the importance of careful sample handling and the prevention of contamination. Part 7 continues this theme with a discussion of practical and analytical aspects of individual sample types, together with recommendations on preparation methods. One chapter deals exclusively with biological reference materials for quality control and others cover food, agricultural, clinical and sea-water samples. Individual elements are dealt with under the headings of selected essential trace elements (Fe, Co, Ni, Cu, Zn, Cr, Mo, Mn, Se, F, I and Si), some common toxic trace elements (Cd, Hg, T1, As and Pb), selected other trace elements (Sn, Li, Al, Sb, Au and Pt) and ‘macro elements’ (Ca, Mg, N, P and S).The 20 chapters describing the determination of these elements contain a wealth of information from correct storage procedures through to specific techniques and interlaboratory comparisons. Part 12 consists of the appendices. Appendix I1 is a very brief description (a couple of pages) of the role of speciation in the analysis of biological materials. The other Appendix contains useful tables, which detail biological and related reference materials in terms of sources, material and element. Throughout this book, good use is made of tables for clearly presenting information. Overall, the producers of this weighty (literally) volume have succeeded in their aim of producing a comprehensive text, suitable for the experienced analyst and novice alike.The emphasis throughout the book, on the need for data quality control via good analytical quality control and assurance methods, and the important role of reference materials, is well placed. The degree of overlap between chapters has been minimized by a conscientious use of cross referencing. Each chapter has its own up-to-date reference list. Although it is quite expensive, this book contains so much useful informa- tion, that it would be a worthwhile investment for both reference libraries and trace analytical laboratories. H. M . Crews Mass Spectrometry By E. Constantin and A. Schnell. Ellis Horwood Series in Analytical Chemistry. Pp. 184. Ellis Horwood. 1990. Price f39.95. ISBN 0-13-555525-6. This book was first published in French and has been translated and revised in English to form part of the series.The preface states the authors’ aims to fill a ‘gap in the series of books in French on mass spectrometry’ by assembling in condensed form the basic essentials and fields of applica- tion. The book is aimed at engineers, scientists, analytical chemists, pharmacologists and chemists as a teaching aid. The style used is almost note-like, with short chapters (often only 3 pages) subdivided into many sections. At this point the work breaks down becoming a non-coherent jumble of almost random thoughts and accounts. For instance, electron ioniza- tion is introduced on p. 14, re-introduced on p. 16 and receives a chapter all to itself on pages 22-24. Other techniques are dealt with in the same manner, with much repetition of material throughout the book.The authors have attempted to cover a very wide range of mass spectral applications but in a volume as slim as this, the somewhat eccentric choice of examples confuses more than it elucidates. One assumes the choice of examples reflects the authors’ own interests, but attempts to cover the analysis of carbon isotopes, reactions of triplet oxygen, study of ammonia superclusters, FAB spectra of peptides and determination of the heat of reaction between strontium ions and water confuse rather than illustrate the power of mass spectrometry, when dealt with as briefly as here. There are numerous introductory texts on mass spec- trometry. Although the book under review is more recent, other texts give a more structured and clear introduction. The most apt summation of Constantin and Schnell’s book is given by the misprint in the table of contents.Under the chapter on nominal and exact mass there is a section on ‘Revolving Power’. Trying to follow a pattern in this work certainly makes your head spin. N . J . Haskins Analysis and Synthesis of Chemical Process Systems Edited by K. Hartmann and K. Klapick. Computer-Aided Chemical Engineering, Volume 4. Pp. 234. Elsevier. 1990. Price US$141 .OO; Df1275.00. ISBN 0-444-9874-2. The understanding of a process system for the conversion of raw materials into products can be gained by one of two routes. Knowing the raw material conditions and properties and the desired product, a system (or process) can be built up of constituent parts, that is, the process knowledge can be derived as a result of a synthesis of the technology.The alternative route is to decompose the process through modelling and simulation, that is, to analyse the technology. This volume by Hartmann and Klapick provides the rules for generalizing the techniques used in these two routes. Aimed at post-graduate students of chemistry or chemical engineering the book provides an overview of the problem, then in two detailed chapters provides theory, calculation methods and finally examples of the techniques for indus- trially important processes. Chapter 3 describes the techniques of modelling and structural analysis of the process. The most important1198 ANALYST, JULY 1992. VOL. 117 fundamental for the calculation and optimization of a chem- ical process is the mathematical description of the essential properties of the elements of the system, consequently it is necessary to develop a knowledge of the elements of the system, to analyse the structure and thereby build the overall model of the process from the constituent element models.Mathematical modelling is recognized by the authors as being a complicated and laborious process, therefore the need to bring the information together in heuristic flow schemes to allow efficient solution is necessary. The chapter is completed with two examples; a steam-heated boiler and of more industrial interest, a reforming plant for production of high octane gasoline. These examples are described in good detail, are easy to follow and provide an excellent introduction to the application of the analysis techniques.Chapter 4 describes the synthesis techniques that allow an optimum process structure to be designed and developed. This synthesis has, up to now, been done intuitively by means of experience and analogies, but is now recognized as the selection of elements and the determination of the coupling of these elements to meet the functional demands of the process. However, the astronomical number of theoretically possible combinations of elements are tempered by the application of the so-called heuristic rules. These rules are plausible but not infallible rules of thumb on the most suitable decision of approach. The approach of this book is to introduce methods and rules, based on a minimum of information, which can be used in the design or revamp of a process to achieve a more favourable system.Reaction paths, reactor systems, separa- tion systems and heat-exchanger networks are examined by the authors in the optimization of new process structures. Early work in process synthesis was characterized by small problems involving few streams, limiting credibility for industrial application. The examples presented in this chapter are of sufficient complexity to create confidence, if not proof, of the benefits of applying the proposed methods. This book is recommended for those seeking an introductory text as a prelude to working in the development of the techniques of process modelling, synthesis or integration. It is not an easy book to read as the concepts are quite complex.The translation from the original German is excellent. T. Magill NMR Applications in Biopolymers Edited by J. W. Finley, S. J. Schmidt and A. S. Serianni. Basic Life Sciences. Volume 56. Pp. x + 515. Plenum Press. 1990. Price $1 15.00. ISBN 0-306-4371 9-8. spectra comes a real gem, an excellent account of what information NMR can give about starch; by Blanshard, Jaroszkiewicz and Gidley. Anyone interested in starch, or what NMR can do in real biopolymer systems, should read this. The next five chapters are devoted to proteins. Of particular value are the articles on soy proteins by Fisher, Marshall and Marshall and on a-lactalbumin by Berliner, Kaptein, Koga and Musci. The latter paper explains how a variety of techniques such as CIDNIP, NOE, paramagnetic binding and ESR can be used to detemine structure in a calcium binding protein.Unfortunately the article on soy is marred by rather poor figures and a rather uncertain relationship between the captions and the spectra above them. The lactalbumin article also has one part of a figure missing, better proofreading would have been welcome here. Two highly readable and informative reviews on forage digestability and carbohydrates at cell surfaces begin a set of five chapters that one imagines come under the heading ‘miscellaneous’ since the remainder are concerned with in vivo NMR in plants and animals. These are interesting articles but one does wonder quite what they have to do, except in a very general way, with food or biopolymers. As one would expect in any book concerned with food, water looms large.As with most of the food literature, the work is long on data but short on quantitative interpretation, authors do not really seem to appreciate that exchange rates, other than in fast exchange limit, exist. The final two chapters are concerned with on-line applications. Whilst these are not strictly biopolymers, they are informative and a useful guide to what is possible. The chapter by Pearson and Adams also produces a most original definition of bound water as ‘the amounts of hydrogen bonded to carbon atoms’. One wonders how this novel definition will affect the views of the contributors on water in food. In conclusion, the book would have been more appro- priately named ‘NMR Applications in Biopolymers and Food’ but does provide a useful source book on the literature and some very informative articles.P. S. Belton Fourier Transform Infrared Spectroscopy in Colloid and Interface Science Edited by David R. Scheuing. ACS Symposium Series 447. Pp. viii + 294. American Chemical Society. 1990. Price $69.95. ISBN 0-841 2-1 895-1. The book was the result of two separate symposia, one was on recent developments in the NMR spectroscopy of carbohy- drates and the other was on NMR applications in food chemistry. The editors have taken the view that the subject matter of both was complementary and that the two sets of contributions should be brought together under one cover. On the face of it this is a sensible move, but the nature of the contributions is such that they fall into rather distinct and not very compatible groups.The first section of the book is very much for NMR initiates. It starts with a very terse account by Perlin of the stereochemical factors affecting chemical shift and coupling in (mainly) small carbohydrate molecules. There then follows an account of 2D solution state methods by Lerner, which has a useful reference list, but an unfortunate dependence on unexplained acronyms. Highly specialized accounts of 2D spectral editing, NMR of peracetylated derivatives and water suppression follow. This rather dry fare is lightened by an elegant and interesting paper on oxygen exchange using I 8 0 isotope effects by Mega and Van Etten. After two lengthy and rather overlapping papers on 2D The fifteen chapters in this book are based on lectures given at a symposium sponsored by the Division of Colloid and Surface Chemistry of the American Chemical Society in April 1990.The Editor, D. R. Scheuing, is to be commended for having produced, so quickly, an eminently readable and informative volume. That it should prove a wide interest is evident from the preface, where the Editor notes that a better understand- ing of colloidal aggregates and interfacial phenomena is of importance commercially in areas as diverse as lubrication, corrosion and the development of medical implant devices. The opening chapter is an overview by the Editor that provides valuable background information and sets the scene for the subsequent more detailed accounts. There follow six chapters relating to colloidal aggregates, Mendelsohn and Davies utilize the CD2 rocking modes of specifically deuter- ated phospholipids to make quantitative studies of conforma- tional disorder as a function of bilayer depth.Wong and Mantsch show that the infrared and Raman spectra of micellar solutions of anionic surfactants as a function of pressure up to 60 kbar provide additional characterizational specificity. Muga and Casal report studies on the effect of addedANALYST, JULY 1992, VOL. 117 1199 cholesterol, as a function of concentration and temperature, on the location of organic molecules such as 9-hepta-decanone in lipid bilayers. Marcott et al. have used near infrared microspectroscopy to analyse the phases present in aqueous surfactant systems such as decyldimethyl phosphine oxide-water.Weers and Scheuing have studied micellar growth, resulting in sphere to rod transitions, induced by changes in electrolyte concentration micelle composition and temperature, by measuring changes in frequency and shape of CH2 stretching and deformation bands. Rathman and Scheuing report an infrared study of the effect of pH on solutions of alkyldimethylamine oxide surfactants, where there are monomer-to-micelle transitions. The remaining eight chapters cover interfacial phenomena. Ulman provides a very useful overview of the different FTIR techniques used for the study of Langmuir-Blodgett and self-assembled films. Chen and Frank discuss adsorption kinetic studies on n-alkanoic self-assembled monolayers and show that stearic acid follows a transient Langmuir adsorption model.Stroeve and co-workers report transmission and grazing angle FTIR measurements on the structure and gas transport properties of asymmetric membranes from the Langmuir-Blodgett deposition of ultra-thin polymeric lipid films on porous supports. Dluhy and Cornell have used internal reflection IR spectro- scopy to investigate the surface-induced first-order thermo- dynamic phase transition of phospholipid monolayer films at the air-water interface. Internal reflection spectroscopy has also been used by Ishida and Griffiths, to study the adsorption of albumin from aqueous solution on to Cu and Ni films, and P-lactoglobulin, gum arabic and alginic acid on germanium. Story et al. have used both internal reflection-absorption and ATR techniques to characterize the adsorption of the enzyme subtillis BPN’ and lysozyme on model hydrophilic and hydrophobic surfaces. Guzonas, Hair and Tripp report on the development of experimental techniques to obtain spectra of adequate inten- sity from monolayers absorbed on mica, which has a low surface area.Finally, Scheuing demonstrates the use of time-resolved spectra for following the interaction between aqueous ethoxylated alcohols and solid hydrocarbons, as a model for the detergency process. This detailed study forms a fitting final chapter to a book that should be read by all spectroscopists who use the infrared technique for structural characterizational purposes. It will surely stimulate new lines of thought in areas removed from colloid and interfacial science.W. F. Maddams Reviews in Computational Chemistry Edited by Kenny B. Lipkowitz and Donald B. Boyd. Pp. xix + 419. VCH. 1990. Price f65.00; DM176.00. ISBN 0-89573- 754-X (VCH); 3-527-27845-1 (VCH Verlagsgesellschaft). I found that the book was partly successful in these aims. It certainly does provide a good overview of the historical development and current status of the areas it covers. The book imparts a useful sense of the significant accomplishments of computational methods as well as describing the important problems remaining in those fields. One comes away with an appreciation that these are indeed very complex topics, fraught with dangers for the unwary. Understandably, however, this book is not a complete textbook on computa- tional methods; it assumes that the reader is already comfort- able with such terms as Hamiltonian, spherical harmonic, electron correlation, secular equations, Foch matrix and self consistent field.Some of the chapters are presented primarily in terms of formal mathematics, with very few graphic illustrations or numeric examples. This approach may help the author cover much material in a short space, but it is not likely to encourage the novice. On the other hand, the chapter on Aspects of Molecular Modeling is more tutorial in nature, giving several specific numerical examples of simple systems. I found this the most instructive part of the book. There is also one .chapter on chemometrics, by Peter C. Jurs’ which is perhaps a little closer to home territory for most analytical chemists.It provides a brief but clear overview of response surfaces, sampling, optimization, signal processing, factor analysis, calibration and mixture analysis and classifica- tion. A more detailed treatment of molecular structure- property relationships is illustrated by examples from Profes- sor Jurs’ work on the prediction of gas chromatographic retention indices and of 13C NMR spectra. The Appendix of this book contains a list of available software packages for molecular modelling, including names, addresses and phone numbers. Software for large-scale machines as well as microcomputers is covered. In looking over this list, I was led to reflect on the great advances in computer hardware that have occurred in the last 30 years. One can now buy, for the cost of a common laboratory single-pan balance, a microcomputer with several megabytes of memory, capable of performing about a million floating point operations per second.Such machines are probably as powerful as some of the computers that were used for the classic work in computational chemistry in the ’50s and ’60s. This provides a wonderfully low-cost opportunity for learning and/or teaching computational methods. This book is well indexed, with both author and subject indices, and the printing and binding are first rate. T. C. O’Haver Atomic Spectroscopy By James W. Robinson. Pp. vi + 299. Marcel Dekker. 1990. Price $99.75 (USA and Canada); $1 19.50 (Export); $55.00 (on orders of 5 or more copies, for classroom use only). ISBN 0-8247-831 1-5. This is a collection of separately-authored chapters that deal mostly with molecular orbital calculations (both ab initio and semi-empirical) and computer-assisted molecular design and simulation.The authors are all experts who have made substantial contributions to their fields. The back cover promises that the volume ‘assumes little or no previous knowledge of the topics and contains a limited amount of mathematics’. The preface claims that the book should be attractive to ‘novices who need to be brought up to date quickly about modern computational chemistry’. I was very interested in these topics in graduate school in the mid 1960s, and, although I have not been involved in this area since then, I felt this book would be a good place to catch up. This book should, according to the preface, be most useful to the practising analytical chemist in a routine industrial or research environment, and also be useful for a university special topics course.The introduction, which is 53 pages long, deals with a wide variety of topics including atomic theory; origins of atomic spectra and a comparison of absorption and emission, optics in spectrometry, reliability of results, and signal and noise (sensitivity). Each of these topics is treated rather sketchily and it is not clear what purpose they serve. There are, unfortunately, many errors and the following is a sample only. For example, in the section on atomic theory the azimuthal quantum number f derives from fundamental, not fine and there are 32 electrons in the N shell, not 18.In fact,1200 ANALYST, JULY 1992, VOL. 117 the whole presentation shows the need for more editing and statements like ‘the energy differences are the difference between these energies’ do not appeal to the reader. In the section devoted to optics a diagram of a single-beam instru- ment is given and the text refers to the Beckman DU spectophotometer. However, the diagram is not that of the DU, which contained a Littrow prism and not an equilateral prism. On page 40 the text on standard additions refers the reader to a figure showing the relationship between the relative error in concentration and the transmittance with a constant error in T. In the section on signal-to-noise the limit of detection is confused with the sensitivity and the use of the term sensitivity when detection limit is intended continues throughout the book.The chapter on atomic absorption spectroscopy is over 100 pages in length and covers all aspects of the subject. However, for emission spectroscopy, there are separate chapters on flame photometry, emission spectroscopy and plasma spectro- scopy. The plasma spectroscopy chapter also includes ICP spectrometry. The book also includes a chapter on atomic fluorescence. These chapters are on the whole useful and interesting and contain far fewer errors than the introduction, but there are still several minor annoyances like the confusion between zinc and potassium (p. 60) and accuracy and precision (p. 61) and the lack of mention of ion formation in Table 2.5. In the discussion of methods used for background correction the author fails to point out that what practising analysts mean when they refer to a blank value is not the same as background signal.The units quoted for Table 5.1 completely defeated me, and so did one of the column headings in Table 6.3. Throughout the book, SI units are seldom used. The reviewer can see no useful purpose in reproducing tables of information on preferred wavelengths, sensitivities etc. that are always available in operating manuals, or in repeating theory on the origin of atomic spectra (pp. 191-194) that has appeared earlier in the book. A statement on p. 282 gives the impression that ICP-MS resulted from some American work reported in 1987! Also, there is absolutely no mention of Gray and Date in the references at the end of the chapter dealing with the technique. The book is really written for students because the level of the presentation would not appeal to practitioners.It cannot be recommended to students, however, because there are far too many inaccuracies. E. J . Newman DECHEMA Corrosion Handbook. Corrosive Agents and Their Interaction with Materials. Volume 7. Aliphatic Ketones, Ammonium Salts, Atmosphere, Potassium Chloride Edited by Dieter Behrens. Pp. ix + 338. VCH Verlags- gesellschaft. 1990. Price DM775.00; f286.00. ISBN 3-527- 26658-5 (VCH Verlagsgesellschaft); 0-89573-628-4 (VCH). This is an English translation of an updated version of sections of the well-known Dechema Werkstoffe Tabellen. The editor remarks in his preface that the Handbooks provide ‘a thorough exploration’ of a vast mass of literature and ‘a painstaking review and evaluation’ of this literature.This claim is well borne out by the articles on the more narrowly- defined topics. The amounts of information presented are huge: 284 references on aliphatic ketones, 623 on ammonium salts, 695 on atmospheric corrosion and 221 on potassium chloride. These are also remarkably up-to-date: almost half the references on atmospheric corrosion date from 1980 or later. The articles present an amazing amount of detailed infor- mation on the durability of a wide variety of metals, inorganic materials, polymers and building materials, including wood and stone. Information is included on such diverse topics as metallographic etching, the effects of solid contaminants and stress-corrosion cracking, and there is extensive discussion of corrosion problems in the fertilizer industry and in reinforce- ments in concrete.Where directly relevant information is not available, considerable trouble has been taken to draw attention to analogous situations that may be useful. Every effort has been made to summarize and cross-index the information in a convenient form for quick reference, and these sections are a monument to the devotion of the compilers and editors. The section on atmospheric corrosion, although it also presents a vast amount of useful information, is less successful. Here a very wide range of environmental conditions can be involved, and there is an extensive body of theory as well as experimental observations and established protective methods.The technique of briefly presenting one or two salient points from each publication, which works well in other sections, here does not quite provide a well-organized overview of the topic, and the information on individual materials is not so comprehensive as the reviews in, say, Ailor’s ‘Atmospheric Corrosion’. This section perhaps suffers from being so up-to-date in that it excludes many of the classical observations that still constitute the groundwork of the subject. This does seem to leave the reader without the means of assessing the published rates of corrosion unless he falls back on the more extensive coverage available in some previous publications. The difficulty here is compounded by the lack of discussion on the considerable fall in sulfur dioxide concentration in many town atmospheres since the period when most of the site measurements were made.Other topics where a comprehensive overview seems to be lacking are volatile corrosion inhibitors and the important matter of predicting rates of corrosion from environmental data. This section undoubtedly contains a great deal of useful information, but it does not seem to me to represent a source of practical advice that can stand alone without reference to more detailed compilations. The English translation is generally good, with a sprinkling of awkward patches and a few incomprehensible ones. G. 0. Lloyd Computerized Quality Control. Programs for the Ana- lytical Laboratory. Second Edition By T. F. Hartley. Ellis Horwood Series in Analytical Chemistry.Pp. 245. Ellis Horwood. 1990. Price f29.95. ISBN 0-13-151614-0. Over the past two decades, attitudes to quality control (QC) have changed. This is partly due to the implementation of mandatory QC schemes by government and prime contrac- tors, and partly by the ever increasing use of the laboratory- based personal computer to extract meaningful statistical data from the raw analytical results. There is now general acceptance that these data make a significant contribution to chemical and pharmaceutical production efficiency. This new edition of statistical analytical data programs reflects the current position. The six chapters are logically arranged. Linear regression, cubic spline and partial sigmoid curves cater for linear and non-linear calibration construction, followed by programs for generating the operating characteristic (OC) curve, the Trigg tracking signal, and a cusum V-mask for the detection of between-batch QC data.This edition includes a new Chapter4 with programs for analytical performance evaluation inANALYST, JULY 1992, VOL. 117 1201 external quality assurance programmes. The influence of non-random errors and the use of personal computers in the laboratory complete the presentation. A similar format is maintained throughout. The programs are listed and accompanied by a detailed analysis of each program segment followed by appropriate worked examples. Bearing in mind the quite different statistics applicable to engineering component and bulk chemical batch sampling, it was initially slightly disconcerting to note the frequent use of engineering analogies to explain and amplify the QC pro- grams.However, further consideration indicates that these analogies are appropriate in the context. That the author works in the field of clinical chemistry is apparent from the frequent reference to pharmaceutical and clinical pathology examples in the text. This in no way detracts from the usefulness of the programs as applied in the industrial chemical QC laboratory. However, the listed programs are applied mainly to single component materials and would require some adapting for multicomponent applications. Curiously, a significant number of the 70 references, which appeared in the text of the first edition, have not been deleted during the second edition editing process and remain listed in the reference list although not appearing in the main text. A useful supplementary reading list is appended.Apart from the statistical programs, listings of routine data capture, filing, and reporting procedures are included as appendices providing a comprehensive computerized system for the QC laboratory. The book is generally well presented with much useful discussion and clear explanation of the statistical techniques involved. It represents a valuable contribution to the literature of QC analytical chemistry. The programs are written in BASIC (Digital Research) developed on a CPM-86v.3.1 computer (Labtam 3000) with a 132 column dot matrix printer. No uncommon features of the BASIC language are used. The programs as presented require a total of 61.7 kBytes and each data file requires 1.5 kBytes storage and IBM compatable 5% or 3% inch floppy disks of the programs are available from the publishers. J .K . Corbett Thermal Analysis. Part E: Pulse Method of Measuring Basic Thermophysical Parameters. By L'udovit Ku bicar. Wilson and Wilson's Comprehensive Analytical Chemistry, Volume XI/. Pp. xx + 341. Elsevier. 1990. Price $148.75; Df1265.00. ISBN 0-444-98851 -3. This book has 15 chapters and, as the main title indicates, deals comprehensively but very mathematically with heat- pulse methods of measuring thermal conductivity, diffusivity and heat capacity of materials. The layout of the chapters is such that the reader is taken logically through the subject. After a general discussion on the problems of the measure- ment of these parameters, each successive chapter deals with a specific part of the many problems associated with the technique.For example, there are chapters on the influence of heat loss from the sample surface, of contact between two bodies, the influence of heat-pulse width and real heat sources, and the effect of all these individual problems combined. The next four chapters deal with the effects produced by real thermometers, sample holders and the temperature stability of the sample and the measurement of thermophysical parameters under industrial conditions. The subject of each chapter is dealt with in a fair amount of detail and each particular subject is well illustrated with many diagrams. Chapter 13 deals with the experimental arrange- ment of the pulse method fairly fully, discussing the apparatus and its automation, processing data and dealing with measur- ing errors.This chapter is followed by a chapter of 34 pages dealing with practical applications, mainly ruby and poly- (methyl methacrylate). The final chapter presents a computer program (in FORTRAN IV) for the computation of some correction factors dealt with in earlier chapters. There are 59 references. Generally this is a well-presented discussion of a very difficult subject and gives a fair insight into the problems associated with the measurement of these thermophysical parameters. The book should prove useful to both those contemplating setting-up apparatus for such measurements and also to those already using these techniques who wish to know more of the possible errors involved and how to minimize them.F. W. Wilburn Processing and Utilization of High-Sulfur Coals 111 Edited by R. Markuszewski and T. D. Wheelock. Coal Science and Technology. Volume 16. Pp; xvi + 814. Elsevier. 1990. Price US $218.00; Dfl 425.00. ISBN 0-444- 887 I 9-9. This volume, based on the International Conference of the same name held in Ames, Iowa in November 1989, comprises the published versions of papers to the conference. The International title is a little misleading, with 55 papers from the USA, 5 from Poland and only 11 from the rest of the world, including 2 from UK. Consequently most of the papers deal with very few coals, Illinois no. 6 and Pittsburg no. 8 have been heavily studied for example.Three of the papers do not even mention sulfur; one on floatability changes in coal, one on the adhesion of air bubbles to the surface of low rank coals and one on the modelling of coal conversion in a mild temperature gasifier (using Illinois no. 6). The quality of the articles indicates a high level of post conference and pre-publication reviewing. The standard of production is very high with few typographical errors. One obvious error is that one page appears twice, p. 466 in the review copy is reprinted with only a minor change as p. 467. There is no index, only a list of titles, which is a drawback if making a search for specific information. The text is divided roughly into seven topic groups: ( i ) a plenary lecture; ( i i ) characterization of high-sulfur coals; (iii) coal desulfurization by physical cleaning; (iv) chemical cleaning and processing; (v) biological processing; (vi) com- bustion and post-combustion control of SO,; and (vii) utilization of high-sulfur coal.An eighth section lists titles of posters but contains no text. The topic groups are not rigid and overlap or include fringe topics. The plenary lecture details the USA National Energy Strategy, environmental pressures are putting new restraints on their ability to use their most abundant domestic fuel, coal. Electricity generation reserves are shrinking across the USA while State officials rush to pull rods from operating nuclear power plants. Meanwhile in the UK, the coal industry is in Government-led decline and the same challenges to coal usage are not seen as being of National importance.The section on characterization of high sulfur coals deals with the shortcomings of the standard analytical methods for forms of sulfur; sulfate and pyritic sulfur and the role of organic sulfur. The transformation of pyritic sulfur to sulfate and elemental sulfur is described, the latter being incor- porated as organic. Coal desulfurization by physical cleaning deals with the removal of pyritic sulfur in mineral matter and gives details of many methods that have been used or are under development. Oxidation of pyritic sulfur causes prob- lems here too. Chemical cleaning and processing can lead to removal of organic and inorganic sulfur, with some loss of1202 ANALYST, JULY 1992, VOL. 117 calorific value of the fuel.Methods include molten alkali hydroxide mixtures, which can lead to removal of 90% of total sulphur, and mild pyrolysis. Biological processing includes the activity of Thiobacillus ferrooxidans, T. thiooxidans, Pseudo- monas putida, Sulfolobus brierleyi on coals and Desulfovibrio desulfuricans on the flue gas. The biological treatments described were long (several days) and not always effective. None of the papers mentioned the quality of coal after treatment, only dealing with the reduction of sulfur content. Combustion and post-combustion control of SO2 covered the familiar ground of flue gas desulfurization and fixation as sulfate in bed materials as well as the magneto hydrodynamic cycle and coal-water mixture firing. This section describes results of engineering plant demonstrations of sulfur reduc- tions and it is surprising to me that very little use is made of thermodynamic calculations to investigate the combustor conditions.There is, however, a good deal of chemistry of processes here. The final section, utilization of high-sulfur coals, covers coal liquefaction, the older processes based on solvent extraction and the newer processes based on low temperature pyrolysis to yield liquids (low-temperature tars) of high hydrogen:carbon ratio and a carbon char. In addition, a variety of other topics is included here, e.g., coal weathering, hydrodesulfurization with a new catalyst, co-firing with gas to offset the efficiency penalties implied by sulfur emission controls, the use of sludge from flue gas desulfurization in the recovery of alumina from fly ash, coal log pipelines and future sulfur markets.This last paper informs the farming commun- ity that when sulfur emission controls are in place, they will have to buy in what they have been getting free in rainfall. This fascinating and excellent book is up-to-date (refer- ences included up to 1989) and is a mine of information for those interested in the chemistry and engineering of the control of sulfur emission from coal. At the price charged, however, you may prefer to fight over the institutional copy rather than buy your own. A. A . Herod Computer-Assisted Method Development for High- Performance Liquid Chromatography Edited by J. L. Glajch and Lloyd R. Snyder. Pp. xxiv + 682. Elsevier. 1990.Price $79.75; Df1175.00. ISBN 0-444-88748-2. It is interesting that the publishers should have considered the release of a book containing a series of papers originally appearing as a special edition of the Journal of Chromato- graphy (vol. 485). However, this is a continually expanding field and the book represents excellent background material for the interested chromatographer in many fields of analysis. The title suggests computer-assistance in method optimiza- tion, however, a number of the methods can equally be applied in the manual mode. As a series of papers there is some logical progression through the subject material although by the nature of these papers there is not any direct linking of one subject to another with a nominal degree of repetition, especially in the introductions. The papers cover a wide spectrum of the methods developed by the research analyst and from the available commercial software pack- ages, from initial screening techniques, which include factorial and mixture design and window diagrams, through to approaches most suited for final searching for the global optimum such a modified sequential simplex.However, one of the most interesting section of papers is in computer simulation and it is in this area that the majority of the recent commercial developments have occurred. It is unfortunate that due to the time lag in publication that a number of the most interesting recent commercial software developments are not included and this has led to a slight bias towards the DryLab system in the applications section.Nevertheless this book ‘of papers’ allows the presence within the laboratory of a reference text that may encourage the analyst to consider, structured schemes of method development more frequently in order to assist in the resolution of complex multicomponent mixtures. Brian J. Clark lmmunochemical Methods for Environmental Analysis Edited by Jeanette M. van Emon and Ralph 0. Mumma. American Chemical Society Symposium Series 442. Pp. x + 229. American Chemical Society. 1990. Price $49.95. ISBN 0-841 2-1875-7. The ACS symposium series was founded in 1974 to ensure rapid publication of symposia proceedings. Hence, the papers and reviews in this volume are not typeset. This results in a set of papers with a variety of production typefaces and some lack of continuity with respect to the inclusion of references and the use of headings.However, despite this, it provides a good over-all summary of the use of immunoassay procedures to monitor a variety of food additives, pesticides, residues and other chemicals. The general overview on antibodies as analytical tools given by Helen Van Vunakis gives a very good introduction to the subject and sufficient references to aid further study. Six papers follow under the general heading of Immunoassay Evaluation Guidelines. These examine meat inspection, toxic waste detection, drug residue analysis, food analysis, analysis of agricultural products and the evaluation of the use of immunoassay in environmental monitoring. In general, the papers overview the subject and critically look at the potential of immunoassays in the areas cited.The depth of the examination varies considerably between the papers, but many useful insights are given. The next section is presented under the heading Academic Advances in Immunoassay Technology and includes papers on the detection of compounds such as picloram, nitroaro- matic compounds, avermectins and residue detection of methoprene. In addition, two of the papers take a critical look at the development, use and evaluation of immunoassays in environmental and pesticide analysis. Both these papers provide useful overviews and examples of the problems involved in immunoassay systems. The third section is called Immunoassay Activities in Industry. It describes immunoassays for clomazone (a herbi- cide), alachlor detection in water, atrazines (herbicides) and maduramicin (an anti-coccidial ionophore) administered in poultry feed.The papers in this section and several of those in the previous section provide considerable background in relation to the chemical nature of the materials studied, the production of drug conjugates for immunization, immunization protocols, antibody production, isolation and characterization and assay development. A number of very useful items of information are given in relation to hapten production and assay evalua- tion. These would be of particular interest to those about to embark on the production of either polyclonal or monoclonal antibodies to drugs or other molecules of low molecular mass. The inclusion of a summary chapter overviewing the general findings of the symposium would have been useful.However, for anyone contemplating immunoassay development for environmental monitoring, this book provides the necessary background and highlights the need for thorough assay evaluation. Richard O’Kennedy and Denise EganANALYST, JULY 1992, VOL. 117 1203 Bioluminescence & Chemiluminescence. Current Status. Edited by P. E. Stanley and L. J. Kricka. Pp. xv + 570. Wiley. 1991. Price f80.00. ISBN 0-471-92993-X. The emission of light by chemical or biological reactions is familiar to anyone who has seen the green glow of fairground bangles or the yellow flash of a firefly’s tail. These two reactions of chemi- and bioluminescence are amongst the most efficient, with quantum yields of about 0.8 photons produced per molecule reacting.Less usually, these spectacular ex- amples have moved on from laboratory curiosities to powerful analytical tools. This volume, the Proceedings of the 6th International Symposium, illustrate the range and versatility of bio- and chemiluminescence methods. In some 550 pages, over 100 papers are presented, dealing with a wide range of subjects from genetic engineering through immunoassays, DNA probes and cellular luminescence to analytical applications and industrial seminars. The tech- niques described encompass protein engineering, chemical synthesis, charge coupled device imaging and automated microbiology. In covering the amount of material presented in this volume the Editors have necessarily restricted the space available for each paper however, although terse, most of the contents are commendably readable.The widespread availa- bility of laser printers is evident from the quality of the (camera ready) print, although perhaps the time has come for editors of such proceedings to specify font style and size to ensure uniformity of appearance. Although the brevity of individual papers often requires some prior knowledge from the reader, for those working in this area the volume provides an excellent ‘snapshot’ of the subject as it stands in late 1990 and is to be recommended. A. E. G. Cass The Sprouse Collection of Infrared Spectra. Book 111. Surface Active Agents Edited by Diana L. Hansen. Pp. xi + 808. Elsevier. 1988. Price Dfl 545.00. ISBN 0-942595-03-3. Peak Table Search Library Software for Book 111.1989. Price Dfl285.00. ISBN 0-942595-05-X. subdivided and arranged by functional classification. Thus, comparison of the absorption characteristics of compounds with similar functionality is facilitated. A reference spectrum for a particular compound is located from the numerical, alphabetical or Chemical Abstracts Registry Number indices in terms of a spectral number that systematically follows through the various classification categories and subdivisions. All spectra were run on Fourier transform spectrometers, equipped with laser-guided interferometers claimed to pro- vide a wavenumber accuracy better than kO.01 cm-1. All spectra are presented in percentage transmission format , over the mid-IR spectral range (4400400 cm-1). Samples were prepared as thin films (liquid or solvent cast) on potassium bromide plates, as recrystallized melts or as pressed bromide discs.In addition, details are given of the quality control rationale adopted, taking care of wavenumber calibration, daily performance and stability checks, and the suppression of atmospheric contamination from water vapour, carbon diox- ide and hydrocarbons. For example, within the field of cationic emulsifiers, wetting and dispersing agents, the simple alkylpyridinium salts yield characteristic, well-defined bands belonging to ring stretching vibrations of pyridine. The five adjacent H atoms of the nucleus, analogous to monosubstituted benzene derivatives, cause strong absorption bands attributed to synonymous and opposing deformation vibrations of the H atoms out-of-plane.The N-alkyl residue shows five bands between 2940 and 720 cm-1. Deformation vibrations of the pyridine ring, or H-deformation vibrations in the plane of the ring are identifiable. All of these features may be found on inspection of Spectrum 217 (cetyl pyridinium chloride). In all, a wide range of surfactants should be identifiable, as the Collection is both representative and comprehensive. The publishers are to be congratulated on their skilful production of this excellent volume. W. A. Straw Determination of the Precious Metals. Selected Instrumental Methods By J. C. Van Loon and R. R. Barefoot. Pp. x + 273. John Wiley. 1991. Price f45.00. ISBN 0-471-92745-7. Micro-Peak Search is a DOS based search algorithm and peak table database for use on IBM-PC and compatible computers.Rapid searching of the infrared spectra of unknown surfac- tants can be made against the Sprouse Collection of Infrared Spectra published in the relevant bound volume. Operation of the software is relatively simple: peak locations from an unknown spectrum are entered and searched against the Collection by matching peak intensities, classified as strong, medium or weak. Typically, between 15 and 20 peak locations would be coded to the nearest whole wavenumber, between 4400 cm-1 and 400 cm-1, but if only a few bands are to be used for searching, it is recommended that these should be selected from the ‘fingerprint region’, characteristic of functionality recognizable as unique to the spectrum under consideration.Matching is quantified in terms of a ‘hit quality index’ (HQI) that approaches zero the better the match between the unknown and the reference spectrum in the Collection. A HQI of less than 0.1 is regarded as an excellent match, and should permit identification of the unknown. The Operator’s Manual offers operational guidance, notes on hardware requirements and on appropriate software, a search example and interpretation against the reference Collection. The latter consists of the spectra of 700 surface-active agents, presented in the customary four categories, viz., anionic, cationic, nonionic and amphoteric, which are then The goal of this book is to gather together methods in current use for the determination of the precious metals in various types of samples and to discuss their inherent advantages and limitations, particularly for the benefit of the non-expert in this field.Consequently, the first half of the book briefs the reader on more general topics pertinent to these analyses, namely; preferred laboratory procedures; principles of the common instrumental techniques; physical and chemical properties of the precious metals; reference materials; sam- pling and sample preparation procedure. Not unexpectedly, one chapter is devoted to fire assay. The remaining four chapters cover selected methods from the literature, classified under the following matrices; ores, minerals and concentrates; rocks, waters and biogeochemical materials; biological materials; and industrial samples. Surprisingly, soils and sediments, the most widely used media in geochemical exploration, are omitted from discussion.The chapter dealing with the principles of instrumental methods could have been more focused on the precious metals, leaving out, for example, details on recommended furnace conditions for all elements save three (Au, Pt and Pd) in the discussion on atomic absorption spectrometry (AAS). The techniques described comprise AAS, inductively coupled plasma atomic emission spectrometry (ICP-AES) , inductively coupled plasma mass spectrometry (ICP-MS) and neutron activation analysis (NAA). AAS dominates throughout the1204 ANALYST, JULY 1992, VOL. 117 book, presumably as the authors believe it is the most widely used of the four cited to determine trace elements (p.9). This may be the case in developing countries but in North America, for example, the proliferation of rugged, efficient, competi- tively priced and highly automated ICP emission spectro- meters in the 1980s has certainly ousted AAS from its foremost position in the 1970s. The section summarizing important chemical and physical properties of the seven elements provides the reader with a useful overview for analytical purposes. The organization and contents of the following chapter entitled Reference Materials are puzzling. Just over three of the 32 pages here focus on reference materials, the term commonly used to describe those standards (e.g., SARM-7) well characterized in their concentrations of the precious metals. The majority of the chapter concerns the general purity of reagents and contain- ers, preparation and verification procedures for instrument calibrating solutions and safety in the laboratory.The importance of obtaining respresentative sample sizes, together with decomposition and preconcentration pro- cedures, particularly fire assay, are well covered in Chapters 5 and 6, a testament to the authors’ considerable experience in these areas. Half the book comprises selected and abridged methods grouped by sample type. The justification for including such information as instrumental operating conditions is to save the reader time in searching out the paper. However, more emphasis on a critical appraisal of current methods and less on reprinting of chosen papers’ contents would be of greater benefit to the neophyte.None of the six published methods selected to represent the analysis of rocks incorporates ICP-AES as the measurement technique and yet this is the predominant instrumentation employed by the commercial sector responsible for the overwhelming majority of Au, Pt and Pd determinations. Also not mentioned is the highly cost efficient and accurate measurement of Au by direct NAA that became so popular in the 1980s, or the low recovery for Au encountered when certain rock types are leached with aqua regia. This reliance on information from the literature tends to present a biased impression of currently employed methods because commercial laboratories publish so little. Typing errors appear to be few (e.g. abundance of Au as 3.5 ppm rather than ppb, p.49). The section on interferences in ICP-MS (p. 41) implies incorrectly that ionization suppression in the plasma is the major source of analyte interference rather effects downstream from the sampler and skimmer. The style of writing flows well and the book serves as a useful compilation of published work on the determination of the precious metals and as a source of information in the important area of sample preparation. I hope that it is only my copy that is short by about 30 pages! Gwendy E. M. Hall Contemporary Electroanalytical Chemistry Edited by Ari Ivaska, Andrzej Lewenstam and Rolf Sara. Pp. x + 458. Plenum. 1991. Price $120.00. ISBN 0-306- 438 1 8-6. This volume is based on the papers given four years ago in Finland at ElectroFinn Analysis, one of a series of European Electroanalysis Conferences (Ireland 1986, Spain 1990, Hol- land 1992).Despite the three-year preparation the book has not dated excessively and contains much of interest to practising electroanalytical chemists; the non-specialist may get some useful ideas particularly from the industrial and pharmaceutical sections. The fifty-three papers are contained in seven sections: electrochemical instrumentation and methods, industrial applications, electrochemical sensors, electrochemical flow analysis, clinical applications, pharmaceutical applications and general. Under instrumentation Faulkner et al. discuss current-to-photon conversion to facilitate electrochemical studies at sub-microsecond timescales: studies with well- behaved mercury ultramicroelectrodes are described.Dia- mond’s account of arrays is topical. Other topics here include photoelectrochemistry, FT Faradaic admittance measure- ments, processor-controlled fast potentiostats, FFT smooth- ing of AC polarograms, and ESR-electrochemical investiga- tions. Industrial process control is covered interestingly by Pungor et al. Explosives analysis receives extensive treatment by Asplung, as does routine environmental analysis by the Bersiers. Biotechnology and plating baths receive attention, as does the use of a controlled-growth mercury-drop electrode (CGMDE) to overcome limitations of the static mercury-drop electrode in control situations. Janata reviews the present state of development of solid phase potentiometric sensors. Biosensing with gas sensors, solid polymer electrodes for gas sensing, sensors for use in fermentation, carbon fibre microelectrodes, and several aspects of ISEs are covered in other papers. Mediators for oxidation of NADH are discussed by Gorton et al.Hansen introduces some new ideas for exploiting electro- chemical techniques in flow injection. Potentiometric detec- tion in IC is covered by Trojanowicz. Cox and Gray point out the paucity of papers on the practical use of modified electrodes in flow systems: they describe a stable ruthenium- modified electrode. Other examples are given, however, by Wallace et al., who also discuss electrochemical modification of electrode surfaces. Other articles cover new aspects of the use of ISEs in flow systems. Blanco et al. discuss the determination of mixtures of pteridines in flow systems using adsorptive stripping voltammetry.A wide range of modern pharmaceutical applications is covered. Smyth et al. discuss the new field of direct immuno- assays utilizing adsorptive stripping voltammetry of large molecules. Publication of conference proceedings as a book is a mixed blessing; often the papers would be more appropriately published as a special volume in a journal. Readers are often disappointed to find that what they hoped was a good modern text is in fact the proceedings of a conference; the same will happen here. Arnold Fogg Statistics in Spectroscopy Howard Mark and Jerry Workman. Pp. xiii + 313. Academic Press. 1991. Price $54.40. ISBN 0-1 2-472530-9. This is a most unusual statistics textbook.Written in a chatty anecdotal style, it is based on a series of columns entitled ‘Statistics in Spectroscopy’ that were published in the journal Spectroscopy. The stated aim of the authors is to provide scientists or graduate students with a tutorial on the proper use of mathematicaYstatistical tools, with reference to spectro- scopy. The intent is to avoid ‘heavy’ mathematics, and emphasize understanding. The book begins with a discussion of probability theory, followed by an introduction to the idea of the hypothesis test and the formulating of a null hypothesis. The concepts of populations, parameters, samples (in the statistical sense), statistics (parameter estimates) and degrees of freedom are explained clearly. Other major topics included are the normal distribution, the central limit theorem, propagation of errors, the t-distribution, the standard deviation and distribution ofANALYST, JULY 1992, VOL.117 1205 the mean, one- and two-tailed tests, limit of detection, biased and unbiased parameter estimates, the variance of variance and the chi-square distribution, binomial and Poisson distribu- tions, the F-distribution, ANOVA, statistical design, pitfalls of statistics, and calibration by means of regression. Thus, there is good coverage of the major topics of ‘traditional’ statistics. I enjoyed the earlier parts of the book: the chatty style, which later started to annoy me, seemed right for explaining abstract topics in an easily understandable fashion. However, I came to think that the book was not quite right for a complete beginner, but would be best appreciated by the reader who has already had a few (possibly abortive) brushes with other statistical texts.Later in the book, it became apparent that this is not a text for the generality of spectroscopists, but rather, much of its message is really only applicable in the sort of work now being done with near infrared (NIR) spectrometers by workers such as the authors. Here, because of the nature of the samples studied (e.g. , various biological solid samples), information can only be gleaned by the use of complicated chemometric procedures. These require computers for implementation and may be rather poorly understood by users. The main thrust of the book is to provide a background in statistics for workers in this area, in preparation for a book the same authors hope to write, in which the concept of variability of data will (they hope) be introduced into multivariate methods.I hope that they will succeed in this extremely valuable but difficult endeavour. However, the title of the present book suggests that the subject matter applies to spectroscopy in general, this is not true for the latter parts. In fact, the discussion of regression and calibration is WRONG when applied in areas other than NIR. In the authors’ view, when regression is used to find a calibration equation, the reference sample concentrations are the dependent variable and the measured absorbances are the independent variable. It appears that this is acceptable in NIR work, because the reference analyses are subject to errors that are much larger than the instrumental measurement error.However, in normal analytical spectroscopy (AA, ICP, UVNIS) standards are almost invariably prepared in such a way that any error is negligible, and the observed random errors occur in the signal measurement. Thus, concentration is the independent variable and absorbance is the dependent one; regression must be carried out in this way, and then the equation transformed to allow calculation of the concentra- tion in unknowns from the corresponding signal measure- ments. The distinction between the two situations is never mentioned in the text. I therefore think that this is not a book that should be recommended for students of general analytical chemistry, even at graduate level, because it could result in considerable confusion.There are some errors that should be noted: on page 12, three minus signs have been replaced by multiplication signs; brackets are missing from ( X - k)/S near the foot of page 106; in the middle of page 153 the first term in each bracket in the expression for LCL and UCL should be 299, not 49; and on page 205, the part and page numbers have been omitted from reference 2 5 4 . Mary Masson Biosensors with Fiberoptics Edited by Donald L. Wise and Lemuel B. Wingard, Jr., Pp. xiii + 370. Humana. 1991. Price $79.50 (US); $89.50 (Export). ISBN 0-89603-202-7. This book presents a well-organized treatment of a timely topic, although the coverage is narrower than the title suggests. The first three chapters present background material.The first chapter presents the generally accepted definition of a biosensor as a device that couples a biologically derived molecular recognition element with a physical trans- duction method, and briefly reviews the more common types of molecular recognition elements and transduction methods. The second chapter reviews fibreoptic chemical sensors with primary emphasis on the various chemical indicator systems that have been coupled to fibreoptics. While the coverage in the first two chapters is broad rather than deep, both include many useful references to the primary literature. The third chapter deals with fluorescent labels. The description of the principles of analytical fluorescence measurements is too short to be useful to anyone without a prior knowledge of the subject.However, there is a good discussion of the factors to be considered in choosing a label and an introduction to current developments in labelling technology. The fourth chapter introduces the major focus of the book. It considers the principles of fibreoptics and the various strategies for coupling them to biological recognition elements to make biosensors. The fifth, sixth and seventh chapters all deal with biosensors based on evanescent wave excited fluroescence. The attractive feature of this approach is that the evanescent wave excites only fluorophors close to the surface of the optical fibre making it possible to optically distinguish fluorophor bound to a reagent on the surface from fluorophor free in solution. The fifth chapter presents the theory of evanescent wave fluorescence in some depth along with confirming experiments.The sixth describes the preparation of a biosensor based on evanescent wave fluorescence. The seventh is a description of instrumentation developed for evanescent wave fluorescence measurements. The authors of chapters five and six are from Ciba-Corning Diagnostics, while the authors of the chapter seven are from ORD in Salem, NH. All three chapters are primary literature. They describe in detail the authors’ own experiments rather than reviewing the literature. Because this information has not been published elsewhere (to this reviewer’s knowledge) and because the authors are the world experts on these topics, these chapters are essential reading for any scientist with an interest in biosensors based on evanescent wave excited fluorescence. Chapter 8 presents a theoretical description of how the rate of response of surface immunosensors is influenced by mass transfer and the kinetics of the binding reaction.This chapter includes a review of optical approaches to surface immunoas- says. The most common approach is based on evanescent wave excited fluorescence. This chapter nicely complements the preceding three chapters. The remaining two chapters treat different topics. Chapter nine presents background information on chemiluminescence and bioluminescence along with a short discussion on ways of configuring light producing reactions as sensors. Chapter ten reviews in vivo measurements of pH, carbon dioxide and oxygen using fibreoptic sensors.While it can be argued that these are not biosensors, this application could have a significant impact on the way the status of a patient in critical care is monitored and has attracted a great deal of commercial attention. This particular chapter focuses on the specifics of the application, discussing issues such as biocompatibility and sterilization. Several topics that should have been included in a book entitled Biosensors with Fiberoptics are missing. There is very little on fibreoptic sensors in which an enzyme serves as the molecular recognition element. The work of Jerry Schultz and others on affinity sensors is only referenced in passing rather than receiving the careful consideration it deserves. The same is true for the work by Sepaniak, Vo-Dinh and colleages to develop immunosensors with the antibody immobilized on the distal end of the fibre.The only discussion of fibreoptics is in chapter four and is rather brief. However, on the plus side, the1206 ANALYST, JULY 1992, VOL. 117 book was brought to press quickly. The primary literature is referenced up to the late 1980s and even 1990. Thus, some of the omissions cited above can be covered by following up on references in the review chapters. W. Rudolf Seitz ~ ~~~~ The Analytical Chemistry of Silicones Edited by A. Lee Smith. Volume 7 72in ChemicalAnalysis: A Series of Monographs on Analytical Chemistry and its Applications (Series Editor, J. D. Winefordner). Pp. xxii + 551. Elsevier. 1991. Price f97.35. ISBN 0-471-51624-4.analysis of silicones range from ppb to 100% both in bulk materials and on surfaces. For the silicone specialist the acquisition of this new volume, Volume 112, is a library necessity to maintain an up-to-the-minute contact with silicone chemistry. R. G. Blezard The Preservation of Food by Irradiation. A Factual Guide to the Process and its Effect on Food By Don Robins. Pp. 119. IBC Technical Services Ltd. 1991. Price f55.00. ISBN 1-85271 -1 49-3. This comprehensive volume is a current, in-depth survey of the analytical chemistry of silicones. It is the work of nineteen specialists, all associated with the same corporate organiza- tion, which is the world’s largest manufacturer of silicone products. Volume 112 is basically a radical update of Volume 41 (1974), which was entitled ‘Analysis of Silicones’, with the same editor (Dr A.Lee Smith) but was the work of fifteen authors, all from this same organization. Analytical advances in these last two decades have been so great that it was deemed necessary to produce a new volume rather than present a second edition of Volume 41. The basic plan of Volume 41 has been roughly maintained and as regard the contributors only the Editor, Helen Klimisch and N. Angelotti from the earlier team have written in the much enlarged Volume 112. The first chapter is very similar to the earlier volume but from then on the divergence becomes more apparent with the introduction of newer ideas and techniques from a new team of specialists with specific treatment of their topics. Dr A. L. Smith introduces a ‘decision tree’ to assist in defining an analytical problem and selecting the most appropriate tech- nique. In 1974 the editor stated that, in many cases satisfactory answers could be obtained with little specialized equipment.The use of the ‘decision tree’ is an appreciation of the large strides taken in instrumental development with silicone technology. Angelotti reviews the analysis of silicone polymers, mix- tures and compositions covering fluids, gums, greases, resins, sealants and elastomers. Of all the techniques covered in this new volume, the field of nuclear magnetic resonance (NMR) spectroscopy has experienced the most growth and change since Volume 41 was published. The new volume has an innovative chapter on personal care applications.The range of silicone containing personal care formulations is extremely wide and this chapter provides guidance for the detection of a silicone, the identification of the specific siloxane polymer and its quantitative assessment. The surface analysis of silicone coatings involves a range of instrumental techniques relating interfacial phenomena. The survey of available techniques is well presented but there is an excessive use of acronyms, which is a feature of current technical literature. Microscop- ical characterization techniques, from optical to analytical electron microscopy, are well described as applied to organo- silicon materials. Instrumental techniques are particularly well described and include chromatographic, NMR, IR, mass spectrometric, atomic spectroscopic and X-ray methods.These techniques are described specifically for the character- ization of silicones. It is reassuring to observe that classical wet analysis procedures are still ‘viable’, particularly when sophis- ticated instrumentation is not readily available. This series of monographs comprising ‘Chemical Analysis’ aims to be definitive references on specific topics. This volume has maintained the high technical level of this series. It is a comprehensive guide to the understanding of the chemistry of organosilicon materials. The techniques described for the International Business Communications (IBC) supplies top- ical information through publishing and electronic data services; this paperback is their first in the food area, following their organization of a two-day conference in March 1990.It has been well produced in A4 format, and well written by an experienced author for a consulting agency. It is not the proceedings of the conference, nor a scientific reference book, nor a referenced technical appraisal, nor a blind defence of (or attack on) a controversial food process; its objective is to provide a balanced, comprehensive and readable overview which will help the widest audience understand the specialized issues involved. In this it should be successful and can be recommended to all those concerned about irradiated food, not least those who have been alarmed by the overstated polemics of the anti-irradiation lobby or by the dismissive approach of their opponents. This review takes the middle path: genuine reasons for concern are discussed judiciously, while the advantages and limitations of the process are both expressed.It will be particularly useful as an informative guide for those non-specialists and newcomers needing a clear unbiased appreciation of the area as at September 1990. The main text comprises seven chapters in which detailed chemistry is deliberately unemphasized. Irradiation is intro- duced in the context of food preservation (8 pp.), and then its effects on molecules, microorganisms, plants and insects are explained (14 pp.). The process of food irradiation and its effects are described (14 pp.). The combination of irradiation with other food preservation processes is outlined and recommended (10 pp.). Legislation and control of the process in 36 countries (14 pp.) is followed by an equally world-wide review of the current status of food irradiation facilities and trade in irradiated foods (12 pp.).However, it is concluded that the successful application of the process depends on consumer acceptance rather than its usefulness to interna- tional trade, so consumer reaction is covered in the final chapter (8 pp.). A glossary of scientific and technical terms (8 pp.), an index (7 pp.) and a select bibliography (4 pp.) complete the book. These will be useful to the non-specialist, but potential readers must note that while cross-references are included , direct individual references to technical primary and review literature are not given in the text. The author also refers to several papers given at the IBC conference which are not easily available.Other minor criticisms include the inadequate discussion of rancidity, the confused text illustrat- ing the radiolysis products of packaging polymers (p. 32) and an unclear figure (3.2). For the analytical chemist, the most relevant overall conclusion is that trade in irradiated food is premature in the absence of a simple and robust detection method; analytical approaches to these crucial diagnostic techniques are briefly reviewed in an appendix (4 pp.), which demonstrates that the scope of the book is much wider than mere analytical science. The chemistry of radiolysis is also treated in an appendix The UK food industry has not been enthusiastic about using irradiation, which is here recognized as a technology looking (8 P P 4ANALYST, JULY 1992, VOL.117 1207 for a use, trying (and failing) to drive the market. The author concludes that lack of effort at consumer education is impeding progress; this factual overview will help overcome this problem by providing a basis for knowledgeable discus- sion and rational judgement. C. Hitchcock Chemometrics: Experimental Design. Analytical Chemistry by Open Learning Edited by E. Morgan. Pp. xviii + 275 Wiley. 1991. Price €25.00. ISBN 0-471 -92903-4. This book starts with a very brief description of several commercial software packages that can be used for general statistics, and a short reference list to several texts on experimental design. Chapter 1 is a review of basic statistics, mainly the F- and t-test and ANOVA.Personally I am surprised that the author starts the book in this manner: I think students need to be motivated by case studies and the need for design and optimization before they invest time learning what a t-test is. There are many excellent books on general statistics for analytical chemists such as the text by Miller and Miller1 and I believe the author should merely refer the interested reader to such a book if required. Chapter 2 discusses the general principles behind blocking and Latin squares and contains several simple numerical examples. Chapters 3 and 4 introduce factorial and fractional factorial designs, expanding on the author’s previous and well written tutorial paper.* I find it strange that the author expects students to use normal probability paper in these chapters; like slide rules and logarithm tables, I think that this approach, although naturally used in historical texts on classical experimental design, is rather dated in these days of user- friendly microcomputers.Chapter 5 discusses in some detail various response surface designs, especially the central composite design, which merits 23 pages. A good feature of the ACOL texts is that they contain self assessment questions and the regular inclusion of small numerical examples is a strong feature of this book. I think that the main difficulty about this book is the word ‘chemometrics’ in the title. The book is not about chemo- metrics, but about classical experimental designs illustrated by simple numerical examples. It excludes most topics in modern chemometrics such as signal processing and multivariate methods, so the title will mislead the reader, and the author neglects to cite some of the main texts on experimental design of interest to chemometricians, in particular the book by Deming and Morgan,3 which pre-dates the present book by nearly four years.The most used design in chemistry (simplex) is not discussed in this book, yet a recent review4 used a computer search to compare the number of papers in the chemical literature on various topics: in 1976-1979 general experimental design merits 266 papers, compared with 27 for simplex; during the period 1988-1989 general experimental design has dropped to 56 papers, whereas simplex has increased to 984. It is hard to see this book being used in chemistry courses.The book is too long for a general undergraduate course in chemometrics, which, to be balanced must cover many topics; it is too low level to be adopted as a graduate level text , and to industrialists the book lacks emphasis on the motivation behind experimental design and does not really take into account modern microcomputer based methods. The book is definitely designed as a teaching text and is not a reference book. Despite these reservations, the book is well written, well organized and well presented. In order to evaluate the potential of this book for use on courses, I looked at the syllabus of a course our University runs on crop protection, mainly for agriculture and biology students: it contains a module on statistics, and the material in this statistics module covers very similar ground to this book.I think that biologists, environmental scientists and students of agriculture would find the approach adopted in the book valuable, and the text would cover most of the statistics they are required to know, thus representing a well balanced and comprehensive course. Some changes in the applications (the level of chemical knowledge assumed in the text is fairly minimal though) would be sufficient to make the book more attractive to non- chemists. R. G. Brereton References Miller, J. C., and Miller, J . N., Statistics for Analytical Chemistry, Second Edition, Ellis Horwood, Chichester, 1988. Morgan, E., Burton, K. W., and Church, P., Chemometrics Int. Lab. Systems, 1989, 5 , 283. Deming, S.N . , and Morgan, S. L., Experimental design: A Chemometric Approach, Elsevier, Amsterdam, 1987. Brown, S. D . , Anal. Chem., 1990, 62, 84R. Basic One- and Two-Dimensional NMR Spectroscopy By Horst Friebolin. Pp. xxi + 344. VCH. 1991. Price DM58.00; €22.00. ISBN 3-527-281 08-8. This book is a translation of a German text that first appeared in 1988 and, during translation, the opportunity both to revise and extend the text has been taken. The book is intended to serve as an introduction to the theory and application of NMR spectroscopy and, as such, it joins a field in which there is much competition. The presentation of the text is excellent and the conceptual development suggests that the layout is based on a well-proven series of student lectures. The first six chapters are aimed at the true beginner with Chapters 1 4 leading carefully through the fundamental principles of the NMR experiment, chemical shifts and couplings to an appreciation of various spin systems whilst Chapters 5 and 6 explain the details of decoupling experiments and empirical correlations for predicting 1H and 13C assign- ments.Chapter 7 is devoted to relaxation mechanisms whilst Chapters 8 and 9 describe many of the pulse sequences in use today in one- and two-dimensional NMR, respectively. Chapter 10 is dedicated to the nuclear Overhauser effect and this is followed by chapters on dynamic NMR, shift reagents, macromolecules and NMR spectroscopy in biochemistry and medicine, including in vivo NMR and magnetic resonance tomography. Each chapter finishes with a bibliography that includes a well researched list of texts for further reading but here the author does the reader a miss-service as these contain ‘only the most important references, limited in general to those that are accessible to students’.In a book that is intended to form the bed rock on which further knowledge will be built, one might hope for a more comprehensive list of references, whilst the student should be encouraged to seek out less available texts as part of the scientific training! By opting to use trivial names the author has, inevitably, introduced some anomalies, for instance neither acetone nor propan-2-one appears in the compound index although dimethyl ketone does. The preceding two paragraphs mention irritations that might be considered minor but, in a book that claims to be a1208 ANALYST, JULY 1992, VOL.117 basic general text, there are some more serious comments concerning the choice of contents. One might accept the author’s argument that phase sensitive modulation and inverse detection can be left out for reasons of space in an introductory text, but the devotion of only seven pages to macromolecules (half of that being on PMMA), with nothing more than a passing reference to the recent development of solid-state NMR, is surprising. Similarly, the exclusion of nuclei other than 1H, 13C and, to a lesser extent 31P, will substantially reduce the impact of the book. Interesting as the last 30 pages are, a more balanced survey of the applications of NMR beyond basic ‘small molecule’ organic chemistry would, I believe, have illustrated to the reader just how far NMR has reached into all areas of molecular research over the last few years. Overall, therefore, the book provides a clear and readable elementary guide to the concepts of modern 1H and 13C NMR spectroscopy of small organic molecules and here offers a useful alternative to other elementary texts.However, failure to make the reader more fully aware of the scope and areas of application of the NMR technique must be considered a deficiency in any book so obviously aimed at the student and ‘beginner’ market. M . J . R. Loadman Liquid Chromatography in Biomedical Analysis Edited by T. Hanai Journal of Chromatography Library. Volume 50. Pp. xi + 296. Elsevier. 1991. Price $154.50; Dfl 1270.00.ISBN 0-444-87451 -8. This book is volume 50 in the Journal of Chromatography Library Series. Each volume describes either the practical application of a specific chromatographic technique or the value of chromatographic methods in a particular area of scientific interest. A book devoted to LC in biomedical analysis is particularly welcome as many previous publications describing LC of small and medium molecular mass organic compounds have been dominated by pharmaceutical and therapeutic drug monitoring applications. Neither feature in this volume, which concentrates on the analysis of physiologi- cal fluids and tissues, for groups of analytes which are involved in both normal and pathological biochemical metabolic activities. It also illustrates the role of LC for both the diagnosis and of monitoring the treatment of a larger number of disease processes. A further refreshing aspect is the Japanese perspective provided by the contributors, which is probably best illustrated by the unusually large number of applications involving post-column derivatization.The book is divided into 12 chapters. The first chapter (C. K. Lim) is a brief overview of sample preparation and the basic LC technique. It is of limited value to the serious investigator as precise, detailed sample preparation is specific to the sample type and analytes under investigation, and, similarly, the choice of chromatographic technique is also discussed in detail in the appropriate chapters. In contrast, the second chapter (T. Hanai) which discusses optimization of LC for biomedically important compounds, exquisitely illustrates the challenge facing the analyst.The author starts by describing the complexity of the sample matrix and the diversity of structures and side chains found in related compounds which may be present in large numbers in a single sample. He then proceeds to preface an excellent chapter on the relationships between the structure of naturally occurring aromatic compounds, especially acids, and their physical and chromatographic properties with the following two sentences: ‘Therefore the optimization of the LC of biomedically important compounds is very difficult. There are no simple solutions or mathematical equations for separating such complicated mixtures in LC, even though many related reports have been published.’ Two other topics of general application illustrated in this chapter and taken up by the other contributors are the diagnostic value of pattern recogni- tion of complex chromatograms and the usefulness of alterna- tive modes of sample preparation, separation and detection for analyte identification.Chapter 3 (Y. Ishida) discusses LC of aminoacids and whilst containing much of the author’s significant work on optimiza- tion of post-column detection of cation-exchange separations, using ninhydrin or 0-phthalaldehyde, is generally disappoint- ing. It does not refer to work later than 1985, since when there have been many significant advances in the analysis of aminoacids in physiological fluids using pre-column derivati- zation and separation using reversed-phase partition systems.Similarly, the section on its application to the study of inborn errors of aminoacid metabolism is so brief, incomplete and inappropriate as to be misleading. Chapter 4 (J. Groto and T. Nambara) is a comprehensive guide to the structure of naturally occurring bile acids and their conjugates and their characteristic distribution in various body fluids. Methods of sample fractionation and chromato- graphy suitable for the free acids, their glycine, glucuronide and sulphate conjugates in various combinations in different body fluids are described. Detection methods include far UV for the native compounds, pre-column derivatization to form a variety of UV absorbing and fluorescent products and a post-column immobilized enzyme reactor with UV, fluores- cence or electrochemical detection.The enzyme used, 3 a-hydroxysteroid dehydrogenase, transforms the 3 a-hydroxyl group into a 3 0x0 group at alkaline pH in the presence of NAD+ . The NADH produced is either detected or is used to reduce phenazine methosulfate to an electroactive product. It is claimed that direct LC analysis of the polar sulfate and glucuronide conjugates is more secure (though less sensitive) than GC-MS of their volatile derivatives which may result in undesirable structural transformation during sample prepara- tion. Chapter 5 (S. Honda) is an equally comprehensive review of methods for simple carbohydrates, uronic acids and oligosac- charides. Partion chromatography and ligand techniques are described.The limitations of sensitivity and selectivity imposed by direct detection using refractometry are con- sidered and, whilst pre-column derivatization methods are listed, most emphasis is placed on the various post-column reactions which have been developed. The one obvious ommission is the relatively recent introduction of pulsed amperometric detectors for the sensitive detection of carbo- hydrates without prior derivatization. Chapter 6 (K. Mori) describes the analysis of the catechol- amines nor-epinephrine, epinephrine and dopamine in plasma, urine and blood cells. It gives only brief mention to brain tissues and fluids in which their metabolites 3’4-dihy- droxyphenyl acetic acid, homovanilic acid, 3-methoxy-4- hydroxyphenyl ethylene glycol and 3,4 dihydroxyphenylethyl- ene glycol, are of equal importance.The urinary acidic metabolites, 3-methoxy-4-hydroxy mandelic acid and homo- vanillic acid whose excretion is elevated in certain types of tumour, such as neuroblastoma, are relegated to a metabolic chart and a brief description in Chapter 12. Whilst analysis for these compounds was revolutionized in the Western hemi- sphere by the introduction of electrochemical (amperometric and coulometric) detection to LC, Japanese investigators have favoured post-column conversion of the aromatic amines to their tri-hydroxyindole derivatives followed by fluorimetric detection. Several automatic instruments, similar to ion- exchange amino acid analysers in design, are available on the Japanese market for this application. They probably have the edge over ECD for specificity but are less sensitive, particu- larly for plasma dopamine.A third alternative is pre-columnANALYST, JULY 1992, VOL. 117 1209 derivatization with 1,2-diphenylethylenediamine and chro- matography of the highly fluorescent condensation products. Chapter 7 (fatty acids), 10 (prostoglandins) and 11 (steroid hormones), all written by T. Hirai, have much in common. In all instances, HPLC methods are in competition with tech- niques such as GC-MS, radioimmunoassay and other immu- nochemical techniques which are superior for specific biomedical applications. Common problems which HPLC techniques have to address are specificity and sensitivity. Both sample fractionation strategies and the formation of a variety of derivatives which enhance sensitivity by using fluorescence or ECD have been developed to overcome these limitations, but the mass spectrometer is still required for the relevant structural information.Nevertheless, these three chapters summarize the advances made to date and suggest further developments. HPLC has become popular, for example, for the isolation and purification of prostanoids. Chapter 8 (C. K. Lim) is devoted to nucleotide analysis. HPLC is particularly suitable for this group of compounds as they can be efficiently separated by ion-exchange and re- versed-phase, ion-pair chromatography. These compounds are also sensitively detected using UV light. Additionally, adenine nucleotides react with haloacetaldehydes to form fluorescent derivatives and some guanine and xanthine compounds are electroactive.Similarly, the application of HPLC to porphrin analysis (Chapter 9) has yielded much clinically and biochemically valuable information. This excellent chapter, written by one of the most active workers in this field (C. K. Lim) summarizes all the relevant details concerning the normal-phase separa- tion of the free porphrins and the reversed-phase chromato- graphy of their methyl esters. The separation of various isomers is illustrated and advantage is taken of their natural fluorescence for detection. The short (4 pages) Chapter 12 on catecholamine and indole metabolites would probably have been better as an addendum to Chapter 6. I presume the lack of the most contemporary information in some chapters may be due to delays in translation.This volume is, however, essential reading for biomedical analysts. R. S . Ersser Quantitative Chemical Analysis. Third Edition By Daniel C. Harris. Pp. xv + 758. Freeman. 1991. Price f42.95 (Hardback); f21.00 (Paperback). ISBN 0-7167- 2171-6. The review copy received was in soft covers (‘paperback’- described as the ‘International Student Edition’), but even this weighed more than 1.6 kg and might be considered more of a tome than a book. It is, however, admirable, clearly written, well presented and likely to be useful from the earliest beginning in chemical analysis until a student is well into his or her university years. Little of relevance has been omitted, the sections include considerations of: units, apparatus, statistics and experimental error, gravimetric analysis, precipitation titrations, acids and bases, chelation, electrochemistry, polarography and related techniques, spectrophotometry and chromatography of many types.Colour plates of good quality show various types of volumetric colours obtained, formation of a diffusion layer during electrolysis, thin-layer chromatography plates and even a range of standards ready for preparing a spectropho- tometric calibration curve. It was pleasing to see that sampling was not forgotten, nor the preparation of samples prior to analysis. However, although optical fibres are mentioned, microscopy in all its forms is conspicuous by its absence. Of particular interest was the chapter on analytical separa- tions, in which are considered practical problems such as the release from plastic food wrapping of volatile compounds giving rise to musty odour. Mention is made of more recent techniques such as supercritical fluid chromatography and affinity chromatography.The section about spectroscopy covers a range of techniques, up to Fourier transform infrared; however, one might have anticipated more extended consider- ation of mass spectrometry. The text is illustrated and illuminated throughout by means of a series of ‘boxes’ containing specific information (as a few examples of these: DNA sequencing with fluorescent labels, a stationary phase that mimics a cell membrane and poten- tiometry with an oscillating reaction). Exercises and problems at the end of each chapter should be useful in testing the understanding of the reader.The concluding chapter contains experiments, examples of which are the spectrophotometric determination of iron in vitamin tablets and EDTA titration of calcium and magnesium in natural waters. An index and glossary are provided, also appendices with logarithms and exponents, solubility products, acid dissociation constants and so forth (and the answers to the problems). While the occasional American phrase (like ‘ . . . gotten off the ground . . .’) still comes as a mild surprise I would recommend this book for libraries at educational establish- ments-perhaps more than one copy, as (regardless of the weight) it is likely to be borrowed frequently. D. Simpson On-line Coupled LC-GC. By Konrad Grob. Chromato- graphic Methods Series. Pp. xxvii + 462.Huthig. 1991. Price DM178.00. ISBN 3-7785-1 872-0. The author of this book Dr. Konrad Grob needs no introduction in the field of gas chromatography in which he is a recognized expert. In this volume he presents a comprehen- sive treatise on the theory, practice, and applications of the coupling of liquid chromatography to gas chromatography. This relatively new technique offers the advantages of LC for initial sample clean-up coupled to the excellent resolution obtained from capilliary GC for separation and detection. The introduction gives an overview of the advantages and disadvantages of the technique and progresses into a chapter on the use of conventional split/splitless injectors for the partial transfer of LC eluents. This is followed by chapters on the theory and design of specialized interfaces for the complete transfer of LC eluents to GC.Of these, two techniques emerge as being advantageous, i . e . , the retention gap technique and the concurrent eluent evaporation tech- nique. While these are suitable for normal phase LC, difficulties can be encountered with reversed phase LC; the problems associated with mobile phases containing a large proportion of water are also discussed. A chapter is also dedicated to the design of LC equipment suitable for these techniques. This includes the use of low flow and syringe type pumps, narrow bore LC columns and, on-line LC detectors with high-pressure cells. The suitability of certain types of LC column packing materials and mobile phases is also discussed. This is followed by specific chapters on the concepts of interfaces using the retention gap and concurrent eluent evaporation techniques. Practical aspects such as transfer temperatures, fraction volumes, column lengths, peak shape, etc., are discussed in detail.A wide range of applications with chromatograms are given for each of the two techniques. These date from 1984 to 1989 and some of the earlier applications are discussed with reference to present day1210 ANALYST, JULY 1992, VOL. 117 knowledge. A final chapter reviews the use of supercritical fluids for sample preparation , with methods for transferring these to GC. The book is well organized, with clearly defined chapters on each aspect of the subject, and with short sub-sections on each specific topic.It is addressed to both the theorist and handyman who wishes to construct his own interface and to those who own a dedicated instrument and wish to know more about its design in order to make optimum use of it. Many of the author’s own experiences are also discussed. For readers who wish to get into the technique quickly without having to read the complete book, the more relevant sections are highlighted. The book is easy to follow and to understand by those with only a basic knowledge of LC and GC, and gives an excellent account of this relatively new technique. W . J. Blanchflower Analytical Applications of Spectroscopy II. Edited by A. M. C. Davies and C. S. Creaser. Pp. ix + 323. Royal Society of Chemistry. 1991. Price f49.50. ISBN 0-851 86-403-1. This book is divided into six sections including the introduc- tion by J.G. Graselli. The sections are Vibrational Spectro- scopy, Microscopy, Mass Spectrometry, Combined Tech- niques and Chemometries and Data Handling. This selection of topics reflects the areas of growth in Spectroscopic techniques that the organizers of the Second Spectroscopy Across the Spectrum meeting have pinpointed since the previous meeting in 1987, and I can find no fault with this selection. The contributors are also to be congratulated in providing a clear insight into their use of these various techniques in solving problems and advancing the field of chemical know- ledge using them. I found the Microscopy and Combined Techniques particularly interesting, although all the authors are to be congratulated for providing such a stimulating collection of papers.This book deserves to be used by all in this field and those who may just be starting out. C. D. Taylor Surfactants Applications Directory. Edited by D. R. Karsa, J. M. Goode and P. J. Donnelly. Pp. 399. Blackie. 1991. Price f55.00. ISBN 0-216-92690-4. The objective of the directory is to provide a listing of surfactant products based on their application, rather than by their type, to allow ready selection of surfactants for a particular use. This is achieved by sub-dividing the two main parts of the index according to industry type. The 16 categories used by the editors being: agrochemicals, construc- tion, general detergents, food, industrial and institutional cleaning, leather and fur, metal working, mineral extraction and processing, miscellaneous, paint, lacquer and ink, paper, petroleum, pharmaceuticals, plastics, textiles and fibres, toiletries. The names and addresses of the suppliers of the surfactant products listed are given in an Appendix at the end of the directory.In part 2, which forms the bulk of the book, the various surfactant products are listed alphabetically by tradename under these categories, with information on the supplier, property, chemical type, form, activity and general com- ments. The latter provides more information either on the use of the products or on their chemical type, although this is still very limited. For more detailed information on the chemical structure of surfactant products ‘Surfactants Europa’ (Tergo- Data, Darlington), provides a useful complement to this directory.Generally, the directory achieves its objective and is a useful source of summary information on applications of surfactants which is not readily obtained from any other single source. The format used by the Editors tends to lead to multiple entries for commonly used surfactants which are listed under many of the categories. This is illustrated by the alcohol ethoxylate Synperonic A7 and the nonylphenol ethoxylate Synperonic NP10-both listed under half of the 16 categories. The directory should prove useful as a reference text for those searching for a choice of surfactants or surfactant properties for a particular application, but would probably be more attractive to potential purchasers if available in paper- back at a lower price! C.D. Watts Microelectrodes: Theory and Applications Edited by M. Irene Montenegro, M. Arlete Queiros and John L. Daschback. Series E: Applied Sciences, Volume 797. Pp. xiii + 497. Kluwer Academic Publishers. 1991. Price Df1245.00; $1 64.00; f85.00 ISBN 0-7923-1 229-5. This book contains 29 papers covering a wide range of subjects presented at the meeting held in Alvor (Portugal) on microelectrodes in May 1990 organized by the NATO Advanced Study Institute. The papers are grouped in sections according to the subject area for example, theory, preparation of electrodes, application. However, some overlap is inevi- table and obviously, theoretical aspects are discussed in each chapter. The papers presented clearly show the advantages of microelectrodes with respect to the capacitive current, IR drop and electrode kinetics.The effects due to the reduction in electrode dimensions are treated together with problems associated with the steady-state and dynamic approach. It is pointed out that the time necessary to reach steady-state conditions decreases linearly with the reduction of the electrode area. The application of the Neumann Integral Theorem to the treatment of irreversible reactions is pre- sented. A special merit of the book is that the problems associated with electrode preparation are treated in detail. For microelectrodes attention is focused on the data treatment to be applied in order to provide reliable results and to techniques applying high scan rates. A short but very useful chapter in this book is devoted to the application of microelectrodes in analytical practice, in the monitoring of electrosyntheses and in corrosion studies.I also wish to point out the importance of the paper dealing with the use of microelectrodes in biological systems. In an another interesting paper the advantages offered by the use of microelectrodes in metal deposition are discussed. This book is warmly recommended to all those who intend to work in the field and get acquainted with both the practical and theoretical aspects. It will also be a useful tool for biochemists concerned with in vivo measurements. A good understanding and thorough consideration of the principles discussed in the book will help researchers avoid misinterpret- ation of the measurements provided by microelectrodes. Erno PungorANALYST, JULY 1992, VOL.117 121 1 Handbook of Thin-Layer Chromatography Edited by Joseph Sherma and Berhard Fried. Chromato- graphic Science Series. Volume 55. Pp. viii + 1047. Marcel Dekker. 1991. Price $165.00 (US and Canada); $198.00 (all other countries). ISBN 0-8247-8335-2. Thin-layer, or planar, chromatography remains one of the most popular, accessible and widely used separation tech- niques. In its simplest forms it is very simple indeed, easily performed by scientists with little chromatographic training or experience. At its most sophisticated it can be very sophisti- cated indeed with instrumentation of very high capital cost. Thus, TLC is a very large topic, and any book hoping to cover it in its totality will have to be big! This book certainly fulfils this criterion with over 1000 pages of text.It is therefore not an easy task to provide a truly comprehensive review and I have not attempted to do so. The comments provided here thus represent my first impressions of the work and a random sampling of those topics of particular interest to me. The 31 chapters of the handbook are divided into two portions. The first 13 chapters (pages 3-350) cover the principles and practice of TLC (i.e., topics such as theory and mechanism, detection and quantification, optimization etc.). The remainder of the book, some 18 chapters (pages 353-1019), is concerned entirely with applications of TLC. These cover, with varying degrees of success, topics ranging from amino acids, drugs, enantiomers, lipids, carbohydrates, pesticides, pigments, polymers, steroids, toxins, to vitamins and inor- ganics.As with all multi-author works some of the chapters are better than others. So for example the chapter on TLC coupled to mass spectrometry (Busch) is excellent, as is the contribution on phenols, aromatic acids and indoles (Tyman) (although ion-pair tehniques are not discussed). In contrast I found the chapter on drugs and pharmaceuticals to be not very useful with 18 of the 39 pages taken up solely with structures. The handbook also contains a glossary, a directory of manufacturers and an index. The index at 15 pages is not overlong for a volume of this size, and I would also have liked to see a compound index to enable the reader to rapidly locate analytes.Overall this is probably a useful addition to the TLC literature. For future editions rather tighter editing to ensure that all the contributions are to the high standards shown by some of the authors will greatly enhance the value of this latest handbook on Thin-layer Chromatography. I . D. Wilson Soil Analysis. Modern Instrumental Techniques. Second Edition Edited by Keith A. Smith. Books in Soils, Plants and the Environment. Pp. viii + 659. Marcel Dekker. 1991. Price US $150.00 (USA and Canada); US$180.00 (all other countries). ISBN 0-8247-8355-7. The objective of this book is to fill the gap between the books that cover traditional methods of analysis and the specialist monographs on individual instrumental techniques, which are usually not written with soil or plant analysis specifically in mind.In the seven years since the first edition was written, there have been many developments in the instrumental techniques that are applied to the analysis of soil and other environmental materials. Some techniques that were not used widely enough to merit inclusion in the first edition have become of much greater significance. For example, inductively coupled plasma atomic emission spectrometry (ICP-AES) has now become the favoured technique for routine multi-element analysis in major soil and plant testing laboratories. Therefore, three new chapters have been added into the second edition. These are Inductively Coupled Plasma Spectrometry by Barry L. Sharp; Ion Chromatography by M. Ali Tabataabai and Nicholas T.Basta; and Analysis of Functional Groups in Soil by Nuclear Magnetic Resonance Spectroscopy by Michael A. Wilson. All eleven chapters of the first edition were retained in revised form. In the mean time, some new techniques were added, for example, Flow-Injection into Chapter 4, Nuclear Analysis in Chapter 8, and Analysis of Carbon and Oxygen Isotope Ratios in Chapter 10. One strength of this book lies in its comprehensive coverage of soil analysis using modern instrumental techniques. Most of the individual chapters are authoritative, well balanced and present a concise summary of each topic. The limitations of the various techniques, such as interference effects, are not discussed in depth by all of the authors. Some authors not only discuss the limitations, but give some worked examples.The volume presents a tremendous amount of recent information (i.e., up to 1988), and extensive citations to specific applica- tions of each instrumental technique. The text is generally thorough, yet comprehensible, and should prove a useful resource to both the inexperienced as well as the expert users of the instruments. In addition to being germane for analysts, this book should also be a useful resource for soil scientists who wishes to know what determinations are now possible, and which techniques offer the best performance. One weakness of this volume lies in its lack of standardiza- tion of terminology, as is often the case with such multi-author books. There is no agreement on the meaning of such terms as precision, detection limit or minimum detectable concentra- tions. The information on the precision and accuracy, that one might require for any of the analytical methods described, is not well covered, nor are there many references to suitable reference materials with which to validate the analyses produced by the methods. An increasing awareness of the importance of method validation, may suggest these topics for inclusion in subsequent editions. Unfortunately, the Index for the volume does not do justice to the contents of the individual chapters. For example, there are no references in the Index to such common topics such as sampling, dissolution, accuracy or detection limits. Overall therefore, the book forms an invaluable asset for both the users and producers of chemical analysis on soils. As a significant improvement on the first edition, it will surely remain a benchmark work on soil analysis. Michael H . Ramsey and Deming Dong A Practical Guide to the Care, Maintenance and Trouble- shooting of Capillary Gas Chromatographic Systems By Dean Rood. Chromatographic Methods Series. Pp. 191. Huthig. 1991. Price $47.00. ISBN 3-7785-1898-4. The publishers of this guide will be well known to chromato- graphers, having produced the established Chromatographic Methods Series. This guide forms part of that series. The guide in its introduction sets out two goals; one of these is to provide practical information that will maximize both capillary column lifetime and the performance of the gas chromatographic system, the other is to provide a trouble- shooting guide in order to reduce or prevent performance breakdown. These two goals are achieved with an extremely well thought out structure. This book is the quintessence of a practical guide; cross-references are the norm and equations kept to a minimum. The table of contents sets out clearly the structure of the guide and is complemented by a subject index at the back of1212 the book. The book is set out in 11 chapters, the first six of which deal with setting up the gas chromatograph. Some basic theory is discussed in addition to choice and installation of columns, carrier gases and test mixtures etc. Detail such as column capacities, which are essential knowledge to the analyst, are given (information that would be difficult to locate elsewhere). The last five chapters are concerned with the running of the instrument, such as operation and maintenance of injectors and detectors, problems and troubleshooting. The section on detectors covers all the most commonly used systems (FID, ECD, TCD, NPD and FPD), although it may have been of more use to exclude the thermal conductivity (TCD), which the author admits to having limited application areas, and include such detectors as the Hall (ELCD) and photoioniza- tion detectors (PID), which are used increasingly. Discussion of each detector is divided into principle of operation, gases, column position, linear range and sensitivity and common problems. This section will be an important source of information to the novice. The troubleshooting section at the end of the book is particularly useful and consists of 36 pages where the most ANALYST, JULY 1992, VOL. 117 frequently occurring problems are highlighted and a list of possible causes. These have been thoughtfully cross refer- enced to the text. For this section alone the purchase of this book would be justified. Diagrams are used sparingly throughout the guide but when they do appear, are clear, uncluttered and convey the necessary information. There is a distinct lack of references (only three are given) and these are biased towards suggested further reading. Judging by the thought that has so obviously gone into the rest of the book, this has probably been a conscious decision. On the negative side, the style of text suggests that the guide has been directly compiled from word processor copy, and is not particularly pleasant to read, although it must be said that this is a purely personal view. Whilst the guide represents little that is new, it does represent an excellent aid to the less experienced and brings together in one small volume, all those tips, suggestions and information that normally take many years to acquire. This book represents very good value for money and should find its deserved place on the work bench, wherever this technique is carried out. P. J. Rennie

ISSN:0003-2654    

DOI:10.1039/AN9921701197

出版商:RSC    

年代:1992

数据来源: RSC

摘要:

1212 ERRATUM ANALYST, JULY 1992, VOL. 117 Ion Chromatographic Study of the Effect of Ammonium Nitrate as a Modifier in Electrothermal Atomic Absorption Spectrometry Muhammad Mansha Chaudhry and David Littlejohn Analyst, 1992, 1 17, 71 3 Page 714, Table 1, lines 3 and 4: fur ‘Anion eluent: 0.75 mmol dm-3 NaHN03 plus 2.2 mmol dm-3 Na2C03’. Read ‘Anion eluent: 0.75 mmol dm-3 NaHC03 plus 2.2 mmol dm-3 Na2C03’.

ISSN:0003-2654    

DOI:10.1039/AN9921701212

出版商:RSC    

年代:1992

数据来源: RSC

摘要:

ANALYST, JULY 1992, VOL. 117 1213 CUMULATIVE AUTHOR INDEX JANUARY-JULY 1992 Aarkrog, Asker, 497, 941 Abdel-Hay, Mohamed H., 157 Abildtrup, Anne, 677 Abrigo, C., 1071 Abu-Abdoun, Ideisan I., 1179 Abu-Bakr, Mohamed S., 1003 Abuirjeie, Mustafa A., 157 Aguilar Gallardo, A., 195 Alarabi, Hosen, 407 Albero, Ma. Isabel, 925 Alder, John F., 899 AlCs Barrero, Fermin, 1189 Ali, Zulfiqur, 899 Allus, Mahmoud A., 1075 Almendral Parra, M. Jes6s, 921 Alonso Mateos, Angel, 921 Analytical Methods Committee, Angeli, Gyorgy Z., 379 Anglov, J. Thomas B., 419 Aoki, Nobumi, 1033 Aras, Namik K., 447 Atienza, Julia, 1019 Aucott, Lorna S., 947 Awaad, Hoda, 981 Axelsson, H., 417 Aydin, Hasan, 43 Baccan, Nivaldo, 1029 Bahari, M. Shahru, 701 Balamtsarashvili, Gyorgy M., Ballesteros, L., 539 Barary, Magda H., 785 Barclay, David, 117 Barefoot, Ronald R., 563 Barek, Jiii, 751 Barnett, Catherine L., 505 Baronciani, Dante, 511 Barros, Flavio Guimarges, 917 Batrakov, G.F., 813 Baumann, Elizabeth W., 913 Baumgartner, Dieter, 475 Baxter, Douglas C., 657 Beckmann, Christiane, 525 Behne, Dietrich, 555 Beltyukova, Svetlana V., 807 Bengtsson, Gunnar B., 1193 Beresford, Nicholas A., 505 Bermond, Alain, 685 Bersier, Pierre M., 863 Berzero, Antonella, 533 Bicanic, Dane D., 379 Bicker, Gary, 767 Biglino, P., 1071 Birkinshaw, Keith, 1099 Bjdmstad, Helge E., 435, 439, 515, 529, 619 Blaauw, Menno, 431 Bobovnikova, Ts. I., 1041 Boenke, Achim, 1093 Bond, Alan M., 857 Bondarenko, Igor I., 795,803 Bonet Domingo, Emilio, 843 Boomer, Dave, 19 Borisov, A. P., 813 Borroni, Pier Angelo, 533 Bourgeois, Serge, 685 Bourgoin, Bernard P., 19 Brahmaji Rao, S., 1037 Brenes, Manuel, 173 Brereton, Richard G., 1075 Bretten, S., 501 Brindle, Ian D ., 407 Brittain, John E., 515 Buckland, Stephen T., 947 Bulgakov, A. A., 1041 Bulska, Ewa, 657 Bunzl, K., 469 Burgess, John, 605 Butler, L. R. P., 230 Byerley, John J., 1145 97,817 807 Byrne, Anthony R., 251, 443, Cacho, Juan, 31 Cai, Pei Xiang, 185 Campbell, Milford B., 121 Campos Venuti, Gloria, 511 Can0 Pavon, JosC M., 1157 Carpena, JosC, 1025 Caruso, Joseph A., 971 Chai, Fong, 161 Chan, Wing Hong, 185 Chang, Xi-jun, 145 Chattaraj, Sarnath, 413 Chau, Y. K., 571, 1161 Chaudhry, Muhammad Mansha, Cheam, Venghuot, 1137 Chen, Hengwu, 407 Cheng, Jie-Ke, 1133 Cheng, Oi-Ming, 777 ChCnieux, Jean-Claude, 77 Chiu, Teresa P.Y., 777 Christensen, Jytte M., 419, 677 Chudinovskyh, T. A., 813 Ciszewski, Aleksander, 985 Clark, David, 863 Coker, Raymond D., 67 Colbert, David L., 697 Colgan, Peter A., 461, 941 Colina de Vargas, Marinela, 645 Cornelis, Rita, 583 Corns, Warren T., 717 Coulter, Brian, 521 Coxon, Ruth E., 697 Cozar-Sievert, Ramon, 963 Craig, Peter J., 823 Creaser, Colin S., 1105 Crespi, Vera Caramella, 533 Crews, Helen M., 649 Criddle, W. J., 701 Cunha, Ildenise B. S. , 905 Cunningham, John D., 521 Das, Arabinda K., 413 Das, Pradip K., 791 Davey , David E., 761 Davies, Alan E., 1055 Dawson, David E., 461 Day, J. Philip, 619 De Beer, Jacques O., 933 de Bruin, Marcel, 431 de Ruig, Willem G., 425, 545 De Spiegeleer, Bart M. J., 933 Delpuech, JeanAJacques, 267 Demshar, Helen P., 959 Deng, Y., 873 Dermelj, M., 443 Devi, Surekha, 1175 Dhingra, Surendra Kumar, 889 Diamond, Sean, 521 Dinesan, Maravattickal K., 61 Dobrowolski, Ryszard, 1165 Doklea, Erika, 681 Donard, Olivier F.X., 823 Duffuaa, Salih O., 1179 Duffy, Jarlath T., 521 Ebdon, Les, 717 Edgar, Duart, 19 Eid, Mohamed A., 981 El Walily, Abdel Fattah M., 981 El-Anwar, Fawzy, 981 El-Din, Mohie Sharaf, 157 El-Hallaq, Yasser H., 447 Ellingsen, Dag, 657 El-Yazbi, Fawzy A., 785 Emteborg, H%kan, 657 Eremin, Sergei A., 697 Erich, M. Susan, 993 Evans, Don, 19 Faas, Christoph, 525 Fang, Wang, 757 Farrahov, I. T., 813 665 713 Ferreira, Vicente, 31 Fichtl, Burckhard, 681 Finster, Ute, 351 Flanagan, Robert J., 1111 Florence, T. Mark, 551 Fogg, Arnold G., 751,989, 1055 Forth, Wolfgang, 681 Foster, Simon E., 989 Frech, Wolfgang, 657 Funtov, Valery N., 1049 Gaare, E., 501 Gaind, Virindar S., 9, 161 Gajendragad, M.R. ,203 Games, David E., 839 Gammelgaard, Bente, 637 Gao, Wen-yun, 145 Garcla Alvarez-Coque, Marla Celia, 831, 843 Garcia Campaiia, Ana M., 1189 Garcia de Marla, Candido, 921 Garcia de Torres, Amparo, 1157 Garcla, Pedro, 173 Garcia Sanchez, F., 195 Garcia-GonzBlez, Maria Teresa, Garmo, Torstein H., 487, 529 Garrido, Antonio, 173 Garthwaite, Paul H., 947 Gatford, Christopher, 199 Gennaro, M. C., 1071 Genova, Nicla, 533 Gokmen, Ali, 447 Gokmen, Inci G., 447 Gomez-Ariza, J. L., 641 Grinberg, Nelu, 767 Gushikem, Yoshitaka, 1029 Haapalainen, Anne, 361 Hall, Tony, 151 Hamalainen, Lea, 623 Hamano, Takashi, 1033 Harada, Keisuke, 1185 Haro-Ruiz, Maria Dolores, 1169 Hashem, Elham Y., 1003 Haswell, Stephen J., 67, 117 Haugen, Lars E., 465, 529 He, Qong, 181 Heininger, P., 295 Heitkemper, Douglas T., 971 Hemmila, Ilkka A., 1061 Hempel, Maximilian, 669 Hendrix, James L., 47 Henzel, Norbert, 387 Hercules, David M., 323 Hermecz, I., 371 Hernandez-Artiga, Maria Hernandez-Laguna, Alfonso, Herrero, Ma Asuncion, 1019 Hill, Steve J., 717 Hintelmann, Holger, 669 Hioki, Akiharu, 997 Hirayama, Kazuo, 13 Hojker, S., 443 Holst, Erik, 707 Hoogmartens, Jos, 933 Hori, Toshitaka, 893 Horn, A., 355 Horrill, A.D., 941 Horvat, Milena, 665,673 Horvath, G., 371 Houalla, Marwan, 323 Houk, R. S., 577 Hove, Knut, 487 Howard, Brenda J., 505 Hu, Shengshui, 181 Huf, Fred A., 425 Hughes, Terence C., 857 Hutton, Robert C., 649 Idriss, Kamal A., 1003 Ioannou, Pinelopi C., 877 1169 Purificacion, 963 1169 Ishibashi, Mumio, 727 Ito, Yoshio, 1033 Jana, Nikhil R., 791 Jansen, A.A. M., 425 Jeran, Z., 673 Johanson, K. J., 941 Johansson, Sven A. E., 259 Jdns, Ole, 637 JuretiC, Dubravka, 141 Kageyama, Susumu, 13 Kalpana, G., 27 Kanda, Yukio, 883 Kanert, George A., 121 Karpov, V. S., 813 Karshman, Samir, 407 Kawase, Akira, 997 Keatinge, M., 941 Keizer, Meindert G., 1009 Kennedy, V. H., 941 Kim, Young-Man, 323 Kirchner, Gerald, 475 Kiss, A. I., 371 Klaeboe, Peter, 335,351, 355, Kocherlakota, Nirmala, 401 Kocjan, Ryszard, 741 Komarevsky, V. M., 813 Konoplev, A. V., 1041 Konstantianos, Dimitrios G., KoroSin, Janez, 125 Koshino, Yukihiro, 967 Koshy, Valsamma J., 27 Koupai-Abyazani, Mohammed Koiuh, Nevenka, 125 Kracke, W., 469 Kravchenko, Tatyana B., 807 Krishnamacharyulu, J., 1037 Kubota, Masaaki, 997 Kurian, Alice, 1173 Landon, John, 697 Langmyhr, F.J., 229 Larkins, P. L., 231 Lau, Oi-Wah, 777 Lauer, Jean-Claude, 387 Laurence, Christian, 375 Laurens, Thierry, 387 Le, Xiao-chun, 407 Ledford, Jeffrey S., 323 Lee, Albert Wai Ming, 185 Leppard, Gary G., 595 Levillain, Pierre, 77 Lian, Wong Fook, 1033 Liebl, Bernhard, 681 Lien, H., 481 Lin, Sinru, 757 Littlejohn, David, 713 Liu, Jin-Chun, 1133 Livens, Francis R., 505 Lognay, Georges, 1093 Lovgren, Timo N . -E . , 1061 Lu, Jianmin, 35 Lubbers, Marcel, 379 Luk, Shiu-Fai, 777 Lukassen, Wendy D., 1009 Luo, Xing-yin, 145 LupSina, V., 673 Luterotti, Svjetlana, 141 Lydersen, Espen, 613 McAulay, Ian R., 455, 521 McCalley, David V., 721 McGee, Edward J., 461, 941 MacNeill, Geraldine, 521 Maguire, R.J., 1161 Mangels, A. Reed, 559 Maquieira, Angel, 1019 Margielewski, Leszek, 207 Marshall, Geoffrey B., 899 Martin, Fabienne, 823 Martinez-Lozano, Carmen, 1025 365 877 R., 11051214 ANALYST, JULY 1992, VOL. 117 Massart, DesirC L., 933 Mastryukov, V. S., 355 Masuda, Akimasa, 869, 1151 Matlengiewicz, Marek, 387 Matsumura, Yasuharu, 395 Matsuoka, Shiro, 189 Mayes, Robert W., 505 Mazalov, Lev N., 795, 803 Medina Hernandez, Marla JosC, Meeussen, Johannes C. L., 1009 Mellqvist, J., 417 Meloni, Sandro, 533 Mennie, Darren, 823 Midgley, Derek, 199 Mierzwa, Jerzy, 1165 Milatit, Radmila, 125 MilosavljeviC, Emil B., 47 Minhas, Harp, 3,237, 695 Misra, Raj K., 1085 Mitsuhashi, Yukimasa, 1033 Moeder, Charles, 767 Momin, Saschi A., 83 Montagu , Monique , 77 Moors, Martine, 933 Morales, E., 641 Moran, Diarmuid, 455, 521 Moreira, Josino C., 989 Moreno Cordero, Bernardo, 215 Morikawa, Hidehiro, 131 Morimoto, Kazuhiro, 977 Moser-Veillon, Phylis B., 559 Mott, Glen E., 953 Muckter, Harald, 681 Mulcahy, Dennis E., 761 Muiioz-Leyva, Juan Antonio, Murer, Ann J.L., 677 Murray, Ian, 947 Musial, Charles J., 1085 Myrvold, B. O., 355 Nakamura, Toshihiro, 131 Narayana, B., 203 Narayanaswamy, Ramaier, 83 Narukawa, Akira, 967 Nawaz, Sadat, 67 Neagle, William, 863 Neddersen, Robert, 577 Nelson, John H., 47 Nemets, Anatoliy M., 1049 Nemets, Valeriy M., 1049 Nerin, Christina, 31 Nevison, Ian M., 947 Nibbering, Nico M. M., 289 Nicole, Daniel, 387 Nieboer, Evert, 550 Nielsen, Bent, 637 Nielsen, Claus J., 335,355, 365 Nielsen, S.P., 941 NikoliC, Sneiana D., 47 Ngren, A., 481 Norris, John D., 3 Novozamsky, Ivo, 23 Obokata, Takao, 849 O’Connell, Gregory R., 761 Oddone, Massimo, 533 Ohno, Tsutomu, 993 Ohtani, Hajime, 849 Oji, Yoshikiyo, 1033 Oka, Hideyuki, 131 Okano, Teruo, 395 O’Keeffe, Ciaran, 461 831, 843 963 Olsen, Inge Lise Brink, 707 Ortiz, J., 539 Ostah, Naman, 823 0stby, Georg, 481,487 Otu, Emmanuel O., 1145 Oughton, Deborah H., 435,481, Owen, Linda M. W., 649 Padalikar, Sudhakar V., 75 Pal, Tarasankar, 791 Pasquini, Celio, 905 Patil, Vitthal B., 75 Patterson, Kristine Y., 559 Peddy, Rao V. C., 27 Pedersen, 0yvind, 529 Peixoto, Carlos R. M., 1029 Pelne, Agrida, 1013 PCrez Pavon, JosC Luis, 215 PCrez-Ruiz, Tomas, 1025 Perpall, Holly J., 767 Petit-Paly, Genevikve, 77 Petrone, Massimo, 511 Petrov, Arcadiy A., 1049 Pfund, B.Valentin, 857 Pilipets, L. A., 813 Plambeck, James Alan, 39 Plaza, Stanislaw, 207 Polko, A. B. S., 613 Popov, V. E., 1041 Porenta, M., 443 Poulsen, Otto M., 677 Powell, Mark J., 19 Preston, Brian, 3 Proctor, Andrew, 323 Puchades, Rosa, 1019 Purdy, William C., 177 Purohit, Rajesh, 1175 Pusztay, L., 371 Qi-Lu, 869, 1151 Quinn, Gregory W., 689 Raczynska, Ewa D., 375 Rafferty, Barbara, 461 Raisanen, Marja L., 623 Ramesh, A., 1037 Ramis Ramos, Guillermo, 843 Ramsey, John D., 1111 Ransirimal Fernando, Angelo, Rao, T. H., 735 Ravindranath, L. K., 1037 Redford, K., 355 Rezvitskii, Victor V., 795, 803 Rideau, Marc, 77 Riise, G., 481 Risica, Serena, 511 Rivikre, J. C., 313 Robinson, Campbell W., 1145 Rocheleau, Marie-JosCe, 177 Rodenas, Vicente, 925 Rodrigues, Jose A., 989 Roepstorff, Peter, 299 Roessner, Frank, 351 Rogani , Antonia , 5 11 Roman Ceba, Manuel, 1189 Romero, Romer A., 645 Rone, Vallija, 1013 RosCn, A., 417 Ross, Lynn M., 3 Rozas, Leonor G., 921 Rubini, Patrice, 387 Ruiz-Benitez, M., 641 Ruostesuo, Pirkko, 361 515, 619 39 Ruprah, Manjit, 1111 Rusterholz, Bruno, 57 Sablinskas, Valdas, 365 Sabri, Suzy M., 785 Sakai, Tadao, 211 Salbu, Brit, 243,435,439,454, Saleh, Hanaa, 87 Saleh, Magda S., 1003 Salzer, Reiner, 351 Saaoshin, V.V., 853 Samson, Isabelle, 933 Sanchez-Pedreiio, Concepcion, Sanyal, Asis K., 93 Saraswati, Rajananda, 735 Sato, Jun, 131 Satsangi, Rajiv K., 953 Scalia, Santo, 839 Schimmack, W., 469 Schnekenburger, J., 87 Segal, Michael G., 505 Seiler, Kurt, 57 Selnas, Tone D.,493 Serradell, V., 539 Sestakov, G., 443 Sevalkar, Murlidhar T., 75 Severin, Dieter, 305 Severin, Michel, 1093 Shen, Miao-Kang, 137 Sheppard, Brenda S., 971 Shi, Yin-Yu, 137 Shibata, Masaru, 1033 Shijo, Yoshio, 977 Shimizu, Hiroshi, 1151 Shpigun, L. K., 853 Shum, Sam C. K., 577 Silbert, Leonard S., 745 Simon, Wilhelm, 57 Singh, Ajai Kumar, 889 Singleton, Diane L., 505 Sipachev, Viktor A., 383 $kogland, T., 501 Slejkovec, Z., 443 Smith, David S., 697 Soledad Garcia, Ma., 925 Solov’eva, G. Y., 813 Soloviov, Anatoliy A., 1049 Solyom, Aniko M., 379 Sperling, Michael, 629 Stegnar, P., 443,673 Steinberg, Karl-Hermann, 351 Steinnes, Eiliv, 243, 454, 501 Stepanets, 0. V., 813 Stephenson, G. Richard, 1105 Stockwell, Peter B., 717 Stoeppler, M., 295 Strand, Per, 493 Streete, Peter J., 1111 Stupar, Janez, 125 Sturgeon, Ralph E., 233 Su, Zhi-Xing, 145 Sugiyama, Masahito, 893 Suliman, Fakhr-Eldin O., 1179 Sultan, Salah M., 773, 1179 Sulzle, Detlev, 365 Suzuki, Katsuhiko, 1151 Syed, Akheel A., 61 Tabata, Masaaki, 1185 Tabuchi, Toyohisa, 189 Taha, Ziad, 35 Taira , Masafumi , 883 481,487, 515, 613, 619 925 Tan, Guan H., 1129 Taylor, David M., 689 Temminghoff, Erwin J.M., 23 Terao, Tadao, 727 Thomas, C. L. Paul, 899 Thomas, J. D. R., 701 Thomassen, Yngvar, 229, 657 Tomas, Virginia, 1025 Torres-Grifol, Juan F., 721 Toyo’oka, Toshimasa, 727 Treiger, Boris A., 795, 803 Tsingarelli, R. D., 853 Tsuge, Shin, 849 Tubino, Matthieu, 917 Tway, Patricia, 767 Uehara, Nobuo, 977 Unohara, Nobuyuki, 13 Uthe, John F., 1085 van den Berg, Constant M. G., van der Struijs, Teunis D. B., Van Loon, Jon C., 563 van Staden, Jacobus F., 51 Veillon, Claude, 559 Vereda Alonso, Elisa, 1157 Ward, Bernard, 329 Vircava, Daina, 1013 Vircavs, Magnuss, 1013 Vohra, Kusum, 161 Wagstaffe, Peter J., 1093 Wahbi, Abdel-Aziz M., 785 Waidmann, E., 295 Waki, Hirohiko, 189 Walsh, Amanda, 649 Wang, Joseph, 35, 985 Wang, Kemin, 57 Wang, Stephen T., 959 Wang, Xiulin, 165 Warwick, Peter, 151 Welz, Bernhard, 629 Westerberg, Lars M., 623 Wilken, Rolf-Dieter, 669 Willie, Scott, 19 Winnewisser, Brenda P., 343 Wolnik, Karen A., 971 Woodgate, Bruce E., 239 Wu, Weh S., 9 Xia, Jin-Lan, 1133 Xu, Yong-Yuan, 1061 Yahaya, Abdul Hamid, 43 Yamamoto, Susumu, 1033 Yano, Tatsuya, 849 Yao, Xing-Dong, 1133 Yasuhara, Hisao, 395 Ye, M., 873 Yin, Xuefeng, 629 Yoshimura, Kazuhisa, 189 Yu, Yu-fu, 439 ZaniC-GrubiSiC, Tihana, 141 Zapolsky, M. E., 853 Zecchini, Pierre, 329 Zefirov, N. S., 853 Zelyonkina, 0. A., 853 Zeng, Yun’e, 1133 Zhan, Guang-yao, 145 Zhang, Shuzhen, 1161 Zhao, Zaofan, 181 Zheng, Shaoguang, 407 Zolotov, Yu. A., 853 589 545

ISSN:0003-2654    

DOI:10.1039/AN9921701213

出版商:RSC    

年代:1992

数据来源: RSC

摘要:

104 ANALYST, JANUARY 1992, VOL. 117 ~ FLPTSROUNDNO 14 ' JANUARY 1991 AFLATOXIN Z-SCORES LABORATORY NO 31 = X LOWER LIMIT FLPTS ROUND NO 14 JANUARY 1991 FAT Z-SCORES LABORATORY NO LOWER LIMIT 31 = X FLPTS ROUND NO 14 JANUARY 1991 LEAD Z-SCORES LABORATORY NO LOWER LIMIT 31 = X APPENDIX 3 Points of the 22 Distribution Values of the critical point for scores resulting from combining n z-scores. A combined score is satisfactory if its magnitude is less than A, questionable between A and B, and unsatisfactory over B. The values are upper 4.55% and 0.27% points of the x 2 distribution corresponding to two-sided Z values of 2 and 3" n 2 3 4 5 6 7 8 9 10 A 6.18 8.02 9.72 11.31 12.85 14.34 15.79 17.21 18.61 B 11.83 14.16 16.25 18.21 20.06 21.85 23.57 25.26 26.90 n 11 12 13 14 15 16 17 18 19 20 A 19.99 21.35 22.70 24.03 25.35 26.66 27.96 29.25 30.53 31.80 B 28.5 1 30.10 31.66 33.20 34.71 36.22 37.70 39.17 40.63 42.08 References 1 IS0 Guide 43-1984 (E), Development and Operation of Labor-a- tory Proficiency Testing. ISO, 1984.2 Proceedings of the Third International Symposium on the Har-monisarion of Quufiry Assurance Systems in Chemical Analysis. Washington, DC, 1989 (ISO/REMCO 184). Analytical Methods Committee. Anulysr 1989. 114, 1693. Boyer, K. W.. Horwitz. W.. and Albert. R., Anal. Cliem.. 1985, 57, 454. Analytical Methods Committee. Analyst 1987. 112. 199. 3 4 5 Paper /I045160 Received August 29, 1991 * The values were calculated by Professor B. D. Ripley104 ANALYST, JANUARY 1992, VOL. 117 ~ FLPTSROUNDNO 14 ' JANUARY 1991 AFLATOXIN Z-SCORES LABORATORY NO 31 = X LOWER LIMIT FLPTS ROUND NO 14 JANUARY 1991 FAT Z-SCORES LABORATORY NO LOWER LIMIT 31 = X FLPTS ROUND NO 14 JANUARY 1991 LEAD Z-SCORES LABORATORY NO LOWER LIMIT 31 = X APPENDIX 3 Points of the 22 Distribution Values of the critical point for scores resulting from combining n z-scores. A combined score is satisfactory if its magnitude is less than A, questionable between A and B, and unsatisfactory over B.The values are upper 4.55% and 0.27% points of the x 2 distribution corresponding to two-sided Z values of 2 and 3" n 2 3 4 5 6 7 8 9 10 A 6.18 8.02 9.72 11.31 12.85 14.34 15.79 17.21 18.61 B 11.83 14.16 16.25 18.21 20.06 21.85 23.57 25.26 26.90 n 11 12 13 14 15 16 17 18 19 20 A 19.99 21.35 22.70 24.03 25.35 26.66 27.96 29.25 30.53 31.80 B 28.5 1 30.10 31.66 33.20 34.71 36.22 37.70 39.17 40.63 42.08 References 1 IS0 Guide 43-1984 (E), Development and Operation of Labor-a- tory Proficiency Testing. ISO, 1984.2 Proceedings of the Third International Symposium on the Har-monisarion of Quufiry Assurance Systems in Chemical Analysis. Washington, DC, 1989 (ISO/REMCO 184). Analytical Methods Committee. Anulysr 1989. 114, 1693. Boyer, K. W.. Horwitz. W.. and Albert. R., Anal. Cliem.. 1985, 57, 454. Analytical Methods Committee. Analyst 1987. 112. 199. 3 4 5 Paper /I045160 Received August 29, 1991 * The values were calculated by Professor B. D. Ripley104 ANALYST, JANUARY 1992, VOL. 117 ~ FLPTSROUNDNO 14 ' JANUARY 1991 AFLATOXIN Z-SCORES LABORATORY NO 31 = X LOWER LIMIT FLPTS ROUND NO 14 JANUARY 1991 FAT Z-SCORES LABORATORY NO LOWER LIMIT 31 = X FLPTS ROUND NO 14 JANUARY 1991 LEAD Z-SCORES LABORATORY NO LOWER LIMIT 31 = X APPENDIX 3 Points of the 22 Distribution Values of the critical point for scores resulting from combining n z-scores. A combined score is satisfactory if its magnitude is less than A, questionable between A and B, and unsatisfactory over B.The values are upper 4.55% and 0.27% points of the x 2 distribution corresponding to two-sided Z values of 2 and 3" n 2 3 4 5 6 7 8 9 10 A 6.18 8.02 9.72 11.31 12.85 14.34 15.79 17.21 18.61 B 11.83 14.16 16.25 18.21 20.06 21.85 23.57 25.26 26.90 n 11 12 13 14 15 16 17 18 19 20 A 19.99 21.35 22.70 24.03 25.35 26.66 27.96 29.25 30.53 31.80 B 28.5 1 30.10 31.66 33.20 34.71 36.22 37.70 39.17 40.63 42.08 References 1 IS0 Guide 43-1984 (E), Development and Operation of Labor-a- tory Proficiency Testing. ISO, 1984.2 Proceedings of the Third International Symposium on the Har-monisarion of Quufiry Assurance Systems in Chemical Analysis. Washington, DC, 1989 (ISO/REMCO 184). Analytical Methods Committee. Anulysr 1989. 114, 1693. Boyer, K. W.. Horwitz. W.. and Albert. R., Anal. Cliem.. 1985, 57, 454. Analytical Methods Committee. Analyst 1987. 112. 199. 3 4 5 Paper /I045160 Received August 29, 1991 * The values were calculated by Professor B. D. Ripley104 ANALYST, JANUARY 1992, VOL. 117 ~ FLPTSROUNDNO 14 ' JANUARY 1991 AFLATOXIN Z-SCORES LABORATORY NO 31 = X LOWER LIMIT FLPTS ROUND NO 14 JANUARY 1991 FAT Z-SCORES LABORATORY NO LOWER LIMIT 31 = X FLPTS ROUND NO 14 JANUARY 1991 LEAD Z-SCORES LABORATORY NO LOWER LIMIT 31 = X APPENDIX 3 Points of the 22 Distribution Values of the critical point for scores resulting from combining n z-scores.A combined score is satisfactory if its magnitude is less than A, questionable between A and B, and unsatisfactory over B. The values are upper 4.55% and 0.27% points of the x 2 distribution corresponding to two-sided Z values of 2 and 3" n 2 3 4 5 6 7 8 9 10 A 6.18 8.02 9.72 11.31 12.85 14.34 15.79 17.21 18.61 B 11.83 14.16 16.25 18.21 20.06 21.85 23.57 25.26 26.90 n 11 12 13 14 15 16 17 18 19 20 A 19.99 21.35 22.70 24.03 25.35 26.66 27.96 29.25 30.53 31.80 B 28.5 1 30.10 31.66 33.20 34.71 36.22 37.70 39.17 40.63 42.08 References 1 IS0 Guide 43-1984 (E), Development and Operation of Labor-a- tory Proficiency Testing. ISO, 1984.2 Proceedings of the Third International Symposium on the Har-monisarion of Quufiry Assurance Systems in Chemical Analysis. Washington, DC, 1989 (ISO/REMCO 184). Analytical Methods Committee. Anulysr 1989. 114, 1693. Boyer, K. W.. Horwitz. W.. and Albert. R., Anal. Cliem.. 1985, 57, 454. Analytical Methods Committee. Analyst 1987. 112. 199. 3 4 5 Paper /I045160 Received August 29, 1991 * The values were calculated by Professor B. D. RipleyV EUROANALYSIS VIII The Eighth European Conference on Analytical Chemistry will be held at the University of Edinburgh September 5-11,1993 Organized by the Analytical Division of The Royal Society of Chemistry on behalf of WPAC/FECS . . cientific Promamme Euroanalysis VIII will cover developments in instrumentation and methodology in all areas of analytical chemistry, with em- phasis on industrial, biomedical and environmental analysis.The programme will be designed to appeal to both practising analytical chemists in industry and those in academia who are teaching and carrying out research. The programme will consist of invited keynote lectures and contributed oral and poster papers. In order to ensure high quality, all contributed papers will be refereed. Social ~osamme A comprehensive programme is being planned for participants and accompanying persons. It will include half- and full-day excursions, and various evening events including a whisky tasting and a Buffet Reception at the Royal Museum of Scotland. Publication All of the invited lectures will be published in a collected volume as the proceedings of the conference.Authors of con- tributed papers will be encouraged to submit manuscripts for publication in either The Analyst or the Journal of Analytical Atomic Spectrometry (JAAS). T a Some of the topics covered are: Industrial Analysis Validation of Analytical Measurements, Process Control Analysis, Materials Analysis (including Surface Analysis), Energy Related Analysis Pharmaceutical Methods and Drug Metabolism, Forensic Science, Bioselective Methods, Trace Elements in Medicine Separation Science, Molecular Spectroscopy, Atomic Spectrometry, Electrmalytical Techniques, Expert Systems and Chemometrics,Coupled Techniques, Sensors, Laser-based Techniques, Flow Analysis Pharmaceutical and Biomedical Analysis Environmental Analysis Atmosphere, Soils/Sediments, Food/Drink,Water Instrumental Techniques Conference Secretariat: Honorary Chairman, E.J. Newman Conference Presidium: D.T. Bums, Belfast (Chairman); J.F.K. Huber, Vienna; L. Niinisto, Espoo; P.G. Zambonin, Bari Secretary and Conference Organizer: Miss P.E. Hutchinson, Analytical Division, The Royal Society of Chemistry, Burlington House, Piccadilly, London W1V OBN, UK Tel. 071 437 8656; Fax 071 734 1227; Telex 268001 All correspondence and requests for further information should be addressed to the Conference Organizer.vi 1992 Alan Date Memorial Award Submissions are invited for the 1992 Alan Date Memorial Award from young scientists active in the area of Atmospheric Plasma Source Mass Spectrometry The closing date for submission is November 30, 1992 Further details can be obtained from: Dr. R.C. Hutton, VG Elemental, Ion Path, Road Three, Winsford, Cheshire CW7 3BX, UK

ISSN:0003-2654    

DOI:10.1039/AN99217000ia

出版商:RSC    

年代:1992

数据来源: RSC