摘要:

Time-resolved Signals from Particles Injected into the Inductively Coupled Plasma Journal of Analytical Atomic Spectrometry KEVYN KNIGHT Department of Chemistry Birkbeck College (University of London) Gordon House 29 Gordon Square London UK WCI H OPP SIMON CHENERY British Geological Survey Keyworth Nottingham U K NGl2 5GG STAN W. ZOCHOWSKI MICHAEL THOMPSON AND COLIN D. FLINT Department of Chemistry Birkbeck College (University of London) Gordon House 29 Gordon Square London UK WCl H OPP Atomic emission signals derived from single particles in the 1-10 pm size range have been observed after injection of refractory oxides and silicates into the inductively coupled plasma by the nebulization of dilute suspensions. Detection limits by mass are in the 1 x 10-l3-l x lo-" g range because of the discrete nature of the signal and the low background against which the signals are observed.True calibration is currently impossible because of the unavailability of particles of accurately known mass but element-specific particle counting is easy and a valuable capability in itself for discrimination and identification of uncommon particles in complex mixtures. Keywords Inductively coupled plasma atomic emission spectrometry; particle; time-resolved signal; element-specijic particle detection; discrimination Previous work' has shown that when particulate matter in the 1-10 pm size range is introduced into an inductively coupled plasma (ICP) running under standard operating conditions atomic emission signals are observed in the form of peaks with a duration of about 0.5 ms.Each peak signal results from the discrete cloud of excited atoms derived from a single particle passing through the observation zone of the ICP. The signals are observed over an effectively zero background interrupted only by discrete events of much shorter duration derived from background-stray light photons thermal emission or external ionizing events. Because the atomic emission signals have a high intensity and a low background noise mass detection limits in the range 1 x 10-13-1 x lo-'' are possible depending on the sensitivity of the atomic line used if the signal is sampled at a suitably high frequency. The equipment previously described' was originally designed to study the particulate products of the laser ablation of refractory targets.2 However it was immediately found to be equally applicable to particles introduced into the ICP by the nebulization of aqueous suspensions.The acquisition of such information is potentially a valuable addition to the repertoire of inductively coupled plasma atomic emission spectrometric (ICP-AES) analytical techniques. It could throw light on fundamental aspects of particle-plasma interactions3 and on the efficacy of injection techniques such as laser ablation and the nebulization of slurries. Mass calibration for discrete particles still remains a prob- lem however. Particles of known composition can be easily obtained but in nearly all instances of available material the mass range of the particles is relatively large. The only materials found so far with particles in the correct size range and with a suitably small variability are the suspensions of latex spheres used to calibrate particle size analysers and electron micro- scopes.Unfortunately the latex particles are not useful for time-resolved studies as they are atypically easy to atomize and because carbon is one of the least sensitive elements for detection by ICP-AES. Other commercially available materials claimed to have narrow size cuts in the appropriate range are too variable for the calibration of mass. For example if a powder contained particles between 2 and 4 pm in diameter the mass range would span a factor of eight. The work of Olesik and Hobbs3 describes a device that can repetitively inject particles of uniform mass into the ICP.However the particles are produced by the desolvation of aqueous solutions. In the present study the concern is with the practical impli- cations of injecting inherently particulate matter especially refractory materials. Work described in the present paper therefore covers quali- tative and semiquantitative aspects of the study. Signals often simultaneous multi-element signals have been obtained from a variety of refractory particulate materials of which the size characteristics have been confirmed by scanning electron microscopy (SEM) and Coulter Counter studies. The possi- bility of identifying particular types of particles in complex mixtures and establishing their relative proportions by count- ing was investigated. EXPERIMENTAL Equipment The equipment used has previously been described in detail.' A standard mono-/polychromator ICP-AES system was modi- fied by replacing the normal electronics.A fast multichannel analogue to digital converter (ADC) and data acquisition system was attached via virtual-earth preamplifiers directly to the anodes of the photomultiplier tubes and a stabilized high- voltage supply was provided. Data collected by the system were treated off-line by means of proprietary and in-house software. Each channel selected was sampled in the present study at a frequency of 20 kHz. The ICP was operated under conditions used for conven- tional analysis of aqueous solutions i.e. aerosol injector gas at 1.0 1 min-' intermediate gas at 0.0 1 min-' and outer plasma gas at 12.0 1 min-' of argon. Signals were transmitted to the spectrometers by optic fibres mounted at a height of 12mm above the load coil and sampling a vertical distance of 17 mm in the ICP.No attempt was made to optimize the system for the observation of individual particles. Suspensions were pre- pared by ultrasonic agitation of the powders with water containing a surface active agent (usually sodium dodecyl- benzenesulfonate) and introduced into the plasma by means Journal of Analytical Atomic Spectrometry January 1996 VoE. 11 (53-56) 53of a Spectro Analytical high-solids (Babington-type) nebulizer mounted in a single-pass spray chamber with no impact bead. The SEM studies showed that both before and after nebuliz- ation suspensions of discrete (not aggregated) particles were obtained. Signals were monitored from photomultipliers serv- ing the following wavelengths Si 288.2; A1 308.2; Fe 259.9; Zr 343.8; and Ca 422.7 nm.125 - v) .$ 100- .- r 0. 'is 75 - t 0 5 50- z 25 - 0 Injection of Silica Particles The materials selected for the initial investigations were two grades of chromatographic silica with mean particle diameters of 3.0 and 7.6 pm. The SEM studies showed that the materials consisted of separated spheroids with a size variation of about f 50% by visual estimation. Suspensions of these materials in water containing respectively 3 and 6 mg 1-l were prepared and nebulized into the ICP. The response of silicon was monitored at the wavelength listed above. I I I I 1 I Synthetic Mixtures of Particles The following experiment was conducted to investigate the potential of time-resolved ICP-AES for the recognition of particles of a particular composition in a complex assemblage. A mixture of three minerals zircon (ideal formula ZrSiO,) olivine [( Mg,Fe)2Si04] and albite (NaAlSisO,) was ground to a fine powder.Each of these minerals contains an element absent in the other two and therefore capable of uniquely identifying a particle of the mineral in the mixture. A suspension of 0.3 g 1-l of the mixture was prepared in water and nebulized into the JCP. A mixture of two pyroxenes was also prepared. Orthopyroxene [ideal formula (Mg,Fe)$i&] and clinopyrox- ene [(Ca,Mg,Fe),Si208] were individually crushed and separ- ately injected into the ICP as a suspension (0.3 g 1-I) in water. The two minerals were hand picked from a single rock specimen so a mixture of the minerals would be a genuinely realistic problem.The elements used to discriminate between the minerals were calcium iron and silicon and appropriate wavelengths were monitored while the suspension was being nebulized. The signals were roughly calibrated by using the relative sensitivities obtained by the nebulization of aqueous solutions. Crushed Olivine for Measuring Multi-element Signals A sample of natural olivine ( Fe,Mg),Si04 known to be homo- geneous was crushed and suspended in water. Responses for iron magnesium and silicon were monitored while the suspen- sion was nebulized into the ICP. RESULTS AND DISCUSSION Silica Particles Typical portions of traces obtained for injection of silica particles are shown in Figs.1 and 2 which portray a series of peaks with a width of about 0.5 ms each corresponding to the passage of one particle through the plasma. The peak heights (and areas) are variable as shown in the histograms in Figs. 3 and 4. The variation arises mainly because of the mass differences between the particles. The duration of the signals from single particles was esti- mated by fitting a Voigtian profile to about 120 peaks in the data sets. The distribution of estimated peak widths at half- height are shown in Fig. 5. Both the value of the mean and the narrow dispersion are what would be expected from single particles passing through the cone of acceptance of the optic fibre light guides. The small proportion of high outlying widths 6o 1 -15 I I I I 1 I 0 2 4 6 8 10 Tirne/ms Fig.1 Sample output obtained on the silicon channel when particles of silica of mean diameter 3.0 pm were nebulized as a suspension 1000 1 800 c .- C $ 400 C 8 200 n - - I I I 0 5 10 15 20 Time/ms Fig. 2 Sample output obtained when particles of silica of mean diameter 7.6 pm were nebulized as a suspension. Same response units as Fig. 1 150 1 0 20 40 60 80 100 Peak height (arbitrary units) Fig. 3 Distribution of peak heights when particles of silica of mean diameter 3.0 pm are nebulized. Same response units as Fig. 1 probably represent overlapping signals from particles injected roughly simultaneously into the plasma. A 3 pm particle of the silica would have a mass of about 15 pg assuming a density of 1.0 g cm-3 (the material is porous). The average signal-to-background noise ratio suggested by Fig.1 indicates that a detection limit of about 1 pg could be achieved by the time-resolved ICP-AES system for the silica particles. Silicon is not a sensitive element when determined 54 Journal of Analytical Atomic Spectrometry January 1996 Vol. 1 125 i 0 100 200 300 400 Peak height (arbitrary units) Fig. 4 Distribution of peak heights when particles of silica of mean diameter 7.6 pm were nebulized as a suspension. Same response units as Fig. 1 35 1 0.00 0.15 0.30 0.45 0.60 0.75 Peak width at half-heightlms Fig. 5 Distribution of peak widths at half height when 7 pm particles of silica were nebulized as a suspension by ICP-AES so more sensitive elements could probably be detected with detection limits of 10-100 fg.The transport efficiency of the system (the proportion of the nebulized particles that reach the plasma) based on an assumed density of 1.0 for the silica particles was of the order of 0.5% for the 7.6 pm particles and 4% for the 3 pm particles. The 7.6 pm particles provided signals with higher peaks than the 3.0 pm but not in proportion to the relative masses of the particles. This effect could result if the vaporization of the larger particles were less complete of if there was a change in the excitation conditions owing to greater local cooling of the plasma gas in the vicinity of a larger vaporizing particle. Such effects have been observed in connection with the vaporization of large water droplets in the conventional nebulization of solution^.^ Both of the foregoing observations are relevant to an understanding of the calibration problems associated with the nebulization of slurries in conventional ICP-AES. Signals From Mixtures of Particles The signals from mixtures of particles were monitored simul- taneously at appropriate wavelengths.Typical signals are shown superimposed in Fig. 6. It is clear that each of the channels is responding separately to a different type of particle. There is no perceptible correlation between the traces. The prospects for identifying particles that contain an exclusive element as a major constituent are therefore good. A more demanding requirement would be the discrimination 625 645 665 685 705 725 745 765 785 805 Time (arbitrary units) Fig. 6 Superimposed simultaneous responses from zirconium alu- minium and iron channels when a mixture of three minerals was nebulized as a suspension Si A O ;a 0 0 0 Fe Fig.7 Apparent normalized compositions of particles of orthopyrox- ene (filled triangles) and clinopyroxene (open diamonds) showing the successful discrimination of the two minerals by nebulization of suspensions between particles that do not contain mutually exclusive elements but merely differ in the relative proportions of their constituents. This situation was approached when a mixture of two pyroxenes was examined. The most discriminating elements were found to be iron and calcium with silicon being less useful. Data for each particle reaching the plasma were plotted on a triangular diagram of normalized calibrated responses for three elements. (Signals were normalized by summing the calibrated responses to loo%.) The diagrams for the two minerals are shown super- imposed in Fig.7. There is an almost complete discrimination between the two pyroxenes mostly in the calcium-iron direc- tion as expected. The small proportion of particles outside the main composition zones could be the result of a failure to separate the minerals completely before crushing. This system showed the potential of time-resolved ICP-AES for recognizing specific types of particles among mixtures by means of their multi-element response signatures. Although only three elements were used together in this demonstration a much larger range could be used in principle with the possibility of better discrimination using methods such as the discriminant functions or neural nets.Such discrimination in real time would be within the capabilities of modern personal computers. Care would be needed to avoid confusion owing to two or more particles entering the plasma almost simul- taneously and producing a discriminant score intermediate between those of the different types of particles. Hence it would be necessary to dilute the suspension to a degree that reduces random overlap of particles to a low level. Journal of Analytical Atomic Spectrometry January 1996 Vol. 11 55Si Fig. 8 Mapping of the apparent normalized compositions of particles of olivine obtained by nebulization of a suspension of particles of a homogeneous material Fe Si Fig. 9 Isometric projection of Fig.8 with vertical lines of height proportional to the total signal intensity Multi-element Signals From Crushed Olivine While it is evident that particles of the silica gave rise to signals of poor repeatability it was not clear that normalized signals from several elements would be equally variable. Normalization would be akin to internal standardization and could therefore compensate to a degree for variations in particle mass or excitation temperature. The normalized calibrated responses for crushed olivine were plotted on a triangular diagram (Fig. 8). Relative strengths of the signals are fairly variable showing an arti- factual variation in apparent composition between the individ- ual particles. The source of the variation is not immediately apparent from the plot.However a plot that shows the overall signal strengths in addition to the normalized signals throws light on the question. Fig. 9 is an isometric projection of Fig. 8 with vertical lines superimposed that show the total signal strength. The base of each line stands on the triangular diagram at a point that maps the apparent composition of the particle while the height of the line is proportional to the overall signal strength. It can be seen that the longer lines are distinctly shifted away from the Mg apex of the triangle in comparison with the shorter lines. A plausible explanation of this diagram is as follows. The longer lines (greater signals) represent more massive particles. Therefore the more massive particles produce a vapour which is comparatively depleted in magnesium.As MgO is consider- ably more refractory than either FeO or Si02 the result is consistent with incomplete vaporization of the more massive particles. Such particles would produce a greater total mass of vapour which would be depleted (relative to the solid) in MgO. Therefore the large variation in Fig. 8 is due to selective vaporization of the larger particles. CONCLUSIONS Studies with signals from the ICP produced by the passage of single particles have so far demonstrated the following points. Peak widths are fairly constant for particles of different mass and composition if the injector gas flow rate is constant. This suggests that peak heights or peak areas would be equally useful measures of response. Under standard operating con- ditions for ICP-AES the typical peak width at half-height is about 0.5 ms which is consistent with rough calculations of the time required for a particle to pass through the cone of acceptance of the fibre transfer optics.Average peak heights for particles of silica in the size range 3-7 pm are not proportional to the mass of the particle. This suggests that larger particles are incompletely atomized or the atoms produced therefrom are less effectively excited. Signals from iron magnesium and silicon obtained during the nebulization of a suspension of olivine show relative attenuation of the magnesium signal from larger particles. This is strongly suggestive of partial and selective volatilization of the larger particles. Signals from particles exclusively containing a marker element that are present in a complex assemblage of particles can be readily identified and counted at a high rate i.e. up to a few hundred per second. Such element-specific particle counting could be developed into a valuable facility for search- ing for rare particles of foreign matter in relatively pure feedstocks or other particulate material. Many of these factors are suggestive of applications in industry or studies in the fundamentals of particle-plasma interactions. Equipment used in this study was provided by the Science and Engineering Research Council. REFERENCES Thompson M. Flint C. D. Chenery S. and Knight K. J. Anal. At. Spectrom. 1992 7 1099. Chenery S. Hunt A. and Thompson M. J . Anal. At. Spectrom. 1992 7 647. Olesik J. W. and Hobbs S . E. Anal. Chem. 1994 66 3371. Olesik J. W. and Fister .I. C. Spectrochim. Acta Part B 1991 46 851. Paper 5/05 145 B Received August 2 1995 Accepted September 18 1995 56 Journal of Analytical Atomic Spectrometry January 1996 Vol. 11

ISSN:0267-9477    

DOI:10.1039/JA9961100053

出版商:RSC    

年代:1996

数据来源: RSC

摘要:

Isotopic Uranium Determination by Inductively Coupled Plasma Atomic Emission Spectrometry using Conventional and Laser Ablation Sample Introduction Journal of Analytical Atomic Spectrometry PHILLIP S. GOODALL AND STEPHEN G. JOHNSON* Argonne National Laboratory- West Analytical Laboratory Engineering Division P.O. Box 2528 Idaho Falls ID 83402-2528 USA The use of inductively coupled plasma atomic emission spectrometry (ICP-AES) for the determination of 235U 238U isotope ratios in U-Zr metal alloys (90% m/m U 10% m/m Zr) is described. Conventional pneumatic nebulization and laser ablation sample introduction techniques were utilized. The results of the determination agreed within experimental uncertainty with isotope ratios determined by thermal ionization mass spectrometry (TIMS) e.g.235U 238U for conventional nebulization = 2.091 & 0.006 for laser ablation = 2.092 0.015 and for TIMS = 2.0940 IfI 0.0004. The precision i.e. the relative standard deviation (RSD) of the sequential determination of the intensities of the 235U and 238U components of the U emission line and the resultant isotope ratios was improved significantly by the use of an intrinsic internal standard (Zr) i.e. RSD = 1.6% to RSD = 0.17%. Keywords Inductively coupled plasma atomic emission spectrometry; uranium isotope ratio; laser ablation; internal standardization The standard technique for the determination of the isotopic composition of the actinide elements is thermal ionization mass spectrometry (TIMS). This technique is extremely accu- rate and precise but frequently requires tedious and lengthy sample preparation and analyte separation.' If the extreme precision and accuracy of the mass spectrometric determination is not required then alternative methodologies based upon atomic spectrometry could have a number of advantages chiefly that of rapidity.The determination of isotope ratios by inductively coupled plasma mass spectrometry (ICP-MS) using both quadrupole and double-sector based instruments is of current interest. The practical limits on the precision of isotope ratio measurements by quadrupole based ICP-MS is ca. 0.05% relative standard deviation ( RSD).2 Preliminary reports using double-sector instruments have indicated that precisions com- parable to those obtained using TIMS are p~ssible.~ For specific applications in the nuclear industry the possibility of using emission rather than mass spectrometric techniques is highly advantageous in terms of minimizing the contamination of instrumentation i.e.inductively coupled plasma atomic emission spectrometry (ICP-AES) and ICP laser-excited atomic fluorescence (ICP-LEAFS) versus ICP-MS or TIMS. The theory of isotopic splitting of atomic emission lines has been dealt with in some detail by Kuhn4 and compendia of isotopic shifts are a ~ a i l a b l e . ~ . ~ A number of reports of the use of ICP-AES7-'' and ICP-LEAFSI2 for the determination of isotope ratios have been published. The isotope composition of Pb and U have been investigated by Edelson and Fassel with the aid of Fabry-Perot interfer~metry.~ Isotopic composi- * To whom correspondence should be addressed.tions of actinides (U and Pu) in nuclear fuel re-processing streams have been examined by Edelson and Fassel' and by D o ~ g l a s . ~ The high-resolution ICP-AES of Pu has been reported by Edelson et a1.I' and Douglas.' Examples of high- resolution spectra of U Np and Pu have also been used to illustrate the power of high-resolution ICP-AES." The isotopic composition of U has been studied using ICP-LEAFS12 whilst a hollow cathode atom cell was used for the examination of the isotopic composition of U by emission ~pectrometry.'~ An interesting application of high-resolution ICP-AES was the determination of total U by isotope dilution ICP-AES.14 The present paper reports on the determination of 235U 238U isotope ratios in U-Zr alloys by laser ablation (LA) and conventional ICP-AES.Two separate types of alloy were examined. The chemical compositions (90% m/m U 10% m/m Zr) of these alloys were similar but the extent of U enrichment differed from 66.9% (Mk. 111) to 69.5% 235U (Mk. IV). EXPERIMENTAL Instrumentation The two-monochromator laser ablation inductively coupled plasma emission spectrometer has been described in detail in a previous paper." The instrument consists of a high-resolution monochromator (1.5 m path length 2400 lines mm-I grating) used to measure analyte emission and a low-resolution mono- chromator (0.5 m 1200 lines mm-' grating) used to measure internal standard emission. This instrument has been subject to improvements in data acquisition hardware and software.The data acquisition and control system described previously has been replaced by an eight channel simultaneous data acquisition card (DT 2838 Data Translation Marlboro MA USA). Control and processing is supplied via programs written in DT-VEE visual programming language. Conventional ICP-AES was performed on this system with the LA sample introduction system replaced by a Scott double- pass spray chamber fitted with a glass concentric nebulizer (J. A. Meinhard Associates Santa Ana CA USA) fed by a peristaltic pump (Rainin Woburn MA USA). The U I1 424.4nm emission line was used for the determi- nation of the 235U 238U isotope ratio. The ICP spectrometer and laser parameters are given in Table 1. Sample Preparation Preparation of isotope standards Samples of uranium oxide (U30,) (0.200 g) of known isotopic composition (NBL U-100 to U-930 New Brunswick Laboratory Darien IL USA) were digested with hot HN03 (10 cm3 of 8 mol dm-3 HN03).The resultant solutions were Journal of Analytical Atomic Spectrometry January 1996 Vol. 11 (57-60) 57Table 1 isotope ratios Experimental conditions for the determination of 235U:238U ICP conditions- Forward power = 840 W Outer gas flow= 16 dm3 min-' Intermediate gas flow =0.8 dm3 min-' Carrier/nebulizer gas flow =0.65 dm3 min-' Viewing height = 7 mm above load coil High resolution spectrometer- Configuration = Single pass First order Entrance/exit slits = 30 pm PMT voltage = 750 V Scan speed = 0.120 nm min Integration time = 0.25 s Wavelength = 532 nm Pulse width = 6 ns Pulse energy= 125 mJ Sample translation velocity =0.05 mm s-' Repetition rate = 10 Hz Laser ablution- allowed to cool transferred quantitatively into calibrated flasks (50.0 cm3) and made up to the mark with water.Preparation of U-Zr alloy digests for inductively coupled plasma atomic emission spectrometry A sample of the U-Zr alloy (1 g) was digested by refluxing with HN03-HF (100 cm3 of 0.5 mol dm-3 HF in concentrated HN03). The resultant solution was boiled to reduce the volume to ca. 40 cm3 and a portion of dilute HNO added (25 cm3 of 2 mol dm- HNO,). This solution was boiled until the volume was ca. 20 cm3 cooled transferred quantitatively into a cali- brated flask (50 cm3) and made up to the mark with water. Prior to analysis by ICP-AES this solution was diluted by a factor of 20.RESULTS AND DISCUSSION Measurement of Isotope Ratios by Conventional ICP-AES Initial Study The spectrum of the U emission from the ICP instrument was acquired over a 0.120 nm window around the U I1 424.4 nm emission line. A total of 240 points were acquired with a dwell time of 0.25 s per point. The spectrum was smoothed using a seven point moving average filter. Examples of the resultant spectra are given in Fig. 1 for both Mk. I11 [Fig. l(a)] and Mk. IV [Fig. l(b)] alloys. After subtraction of the background the peak 235U emission was ratioed with respect to the peak 238U emission yielding values of 2.04 (Mk. 111) and 2.28 (Mk. IV). Analysis using TIMS yielded values for the 235U 238U isotope ratios of 2.094 & 0.025% (Mk. 111) and 2.38 1 & 0.025% (Mk.IV). These mass spectral isotope ratios are based upon 70 I I Fig. 1 Emission spectrum of the isotopically split U I1 424.4 nm emission line broken line Mk. I11 alloy; and solid line Mk. IV alloy the gravimetric abundance of the isotopes. The results sug- gested a 3-5% negative bias in the determination of U isotope ratios by ICP-AES. Derivation of Bias Factor The application of an empirical correction factor derived from measurement of the emission ratios of solutions of certified reference materials of known isotopic composition provides a means of correcting for the apparent inaccuracy in the determi- nation of isotope ratios by ICP-AES. The emission ratios of the isotopically shifted line pair of the U I1 424.4 nm emission line were determined for six certified reference materials of known isotopic composition. The 235U enrichment of these reference materials is nominally 10 20 35 50 75 and 93%.This was repeated for a total of five sets of measurements each of which was performed on a separate day. These results and the linear regression coefficients are shown in Table 2 and the resultant correction factor is 235U 238U isotope ratio = [(235U 238U emission ratio) + 0.0127]/0.9820 Determination of ='U 2381J Isotope Ratios in Metal Alloys by Conventional ICP-AES The 235U 238U isotope ratio of Mk. I11 and Mk. IV fuels was determined by measuring the 235U 238U emission ratio of the U I1 424.4nm line. The value was corrected using the pre- viously derived empirical correction term. Multiple determi- nations of at least six replicates were performed on four Table 2 235U 238U emission ratios for U isotope certified reference materials (NBL U-100 to NBL U-930) 2 3 5 ~ .2 3 8 ~ isotope ratio 0.1122 0.248 1 0.5396 0.9971 3.1260 17.1306 Slope Intercept r 234U 238U emission ratio Run 1 0.1182 0.2795 0.5330 0.9489 2.998 0.9810 0.99999 16.81 - 0.00575 Run 2 0.1068 0.2488 0.5296 0.9439 3.002 0.9636 0.000490 0.9999 16.9 1 Run 3 0.1186 0.2559 0.5197 0.9644 2.946 16.78 0.9796 -0.0180 0.9999 Run 4 0.1160 0.2595 0.5370 0.9820 2.874 0.9673 0.9999 16.85 -0.0118 Run 5 0.1200 0.2588 0.5400 0.9737 3.030 0.9339 0.1021 0.9999 16.77 Mean 0.1159 0.2605 0.5319 0.9626 2.970 16.82 0.9820 0.9999 -0.0127 S*(" - 1) 0.0053 0.01 14 0.0079 0.0161 0.0616 0.0573 - - - * s = Standard deviation. 58 Journal of Analytical Atomic Spectrometry January 1996 Vol.1 1Table 3 U isotope ratio measurements (235U 238U) by ICP-AES A. Mk. I11 alloy (67.5% 235U enrichment)- Mean deviation RSD(%) n 2.15 0.025 1.16 6 2.10 0.0 19 0.89 8 2.10 0.049 2.33 6 2.10 0.041 1.93 6 Standard Result by mass spectrometry = 2.094 Ifr 0.005 B. Mk. I V alloy (69% 235 U enrichmentt Standard Mean deviation RSD(%) n 2.409 0.023 2.380 0.035 2.412 0.034 2.401 0.06 1 0.93 1.48 1.40 2.55 Result by mass spectrometry = 2.38 1 -t 0.006 separate occasions. These results are shown in Table 3. The precision of any set of measurements could be expected to lie within the range of 0.9-2.4% RSD whilst the day to day variability is < 2% RSD. The emission spectrometry method for a particular set of determinations yielded in all but one case isotope ratios that were indistinguishable statistically from the mass spectrometric results at the P = 95% probability level and for the majority at the 99% level.Over the entire data set isotope ratios determined by ICP-AES were indis- tinguishable at the P = 99% level from those derived from TIMS. The precision of the isotope ratio measurements was reduced by the use of a detector that does not allow simultaneous monitoring of the individual components of the isotopically split U emission line. Consequently short-term fluctuations in the amount of analyte delivered to the atom cell introduce noise into the isotopic determination. The precision of the isotopic measurements could be improved by the use of the emission from an intrinsic internal standard.16 This internal standard could be a matrix species (e.g.Zr) or the analyte itself. In the latter case a non-isotopically split or unresolved isotopically split U emission line can be monitored. The improvement in precision obtained by the use of an intrinsic internal standard is demonstrated by the results shown in Table 4 for the duplicate determination of the U isotope ratio of a digest of Mk. I11 fuel using either Zr I1 357.7 nm (Table 4 (A) or U I1 385.9 nm emission (Table4 B) as the internal standard. The emission from the internal standard and the U emission spectrum were acquired simultaneously using the dual monochromators of the ICP instrument. The use of Zr as an intrinsic internal standard improved the precision of the determination from 0.62 and 1.64% RSD to 0.29 and 0.17% RSD respectively.This improvement in pre- cision is significant (95-99Y0 confidence from 0.62 to 0.29% RSD) and highly significant (>99% confidence from 1.64 to 0.17% RSD). There was no significant difference between the precision of the two sets of data when Zr was applied as an intrinsic internal standard (> 99% confidence from 0.29 to The use of U as an intrinsic internal standard improved the precision of the results from 1.57 and 2.08% RSD to 0.64 and 1.17% RSD respectively. This improvement in precision is significant (95-99% confidence from 2.08 to 1.17% RSD) and highly significant (>99% confidence from 1.17 to 0.64% RSD). The precision of the two sets of data differed significantly when U was applied as an intrinsic internal standard (>99% confidence 1.17 and 0.64% RSD).A comparison between the use of U and Zr as an intrinsic internal standard indicated a significant difference in the precision of the two closest sets of 0.17% RSD). Table 4 U isotope ratio measurements (235U 238U) by ICP-AES with the application of an intrinsic internal standard A. Z r as intrinsic internal standard (duplicate data sets)- Zr II 357.685 nm emission as intrinsic internal standard No internal Internal No internal Internal Parameter standard standard standard standard 2.084 2.087 2.08 1 2.079 Mean s(n - 1) 0.034 0.0036 0.01 3 0.0060 RSD(%) 1.64 0.17 0.62 0.29 n 5 5 8 8 B. U as an intrinsic internal standard (duplicate data sets)- U II 386.0 nm emission as intrinsic internal standard No internal Internal No internal Internal standard standard standard Parameter standard 2.05 1 2.049 2.101 2.100 Mean s(n - 1) 0.032 0.013 0.044 0.025 RSD(%) 1.57 0.64 2.08 1.17 n 14 14 16 16 C.Precision of the internal reference measurement Zr I1 357.7 nm U I1 386 nm U I1 424.4 nm RSD(%) 2.39 1.16 0.89 data (U = 0.64% RSD Zr = 0.29% RSD). Zirconium appeared to offer the greatest gains in precision for the determination of the 235U:238U isotope ratio and was used as the intrinsic internal standard in the LA-ICP-AES experiments. The surprising result that Zr I1 357.7 nm emission provided a more accurate internal reference for the U I1 424.4nm emission was investigated further. The precision of the reference measurement was assessed with respect to U I1 386.0 Zr I1 357.7 and U I1 424.4 nm emission lines (Table 4C).The pre- cisions of the Zr I1 357.7 and U I1 424.4nm emissions were similar (>99% confidence) but that of the U I1 386.0 nm emission differed significantly from both Zr I1 357.7nm (95-99% confidence) and U I1 424.4nm emission (>99% confidence). This phenomenum is under further investigation. The determination of 235U 238U isotope ratios by ICP-AES was shown to be feasible and good accuracy and precision coupled with a rapid measurement technique and simple sample preparation demonstrated. The savings in time for the ICP-AES method compared with the mass spectrometric tech- nique are potentially very significant. The mass spectrometric procedure for irradiated materials includes laborious separa- tion stages to isolate the U prior to measurement.The longest stage in the ICP-AES determination is the requirement to digest the sample a stage common to both the ICP-AES and TIMS procedures. The application of laser ablation method- ologies has the potential to reduce the total ICP analysis time of 1-1.5 h to 1-1.5 min. The ICP-AES technique becomes an attractive method for rapid U isotope determinations where the superior accuracy and precision obtainable with a mass spectrometric determination are not required. Determination of 235U 238U Isotope Ratios in Metal Fuels by LA-ICP-AES Samples for LA were obtained by mechanical shearing of the as-cast U-Zr alloy rods. The sheared surfaces were irregular and in three of the four cases the topography was dominated by a brittle fracture surface. No additional sample surface preparation was attempted and would have been extremely difficult for irradiated samples.The samples were mounted in a stainless-steel sample holder and secured using set screws. The LA parameters are given in Table 1. The ablation cell was translated under the laser. Journal of Analytical Atomic Spectrometry January 1996 Vol. 11 59The ratio of the 235U and 238U components of the U I1 424.4 nm emission line were determined and the empirical bias correction derived earlier was applied. Zirconium was used as an intrinsic internal standard to correct for pulse to pulse laser instability to account for the varying topography of the alloy surface and non-simultaneous measurement of the isotope ratio.The use of an intrinsic internal standard is essential for the determination of 235U 238U isotope ratios by LA-ICP-AES. More accurate and precise results were obtained with the application of Zr as an internal reference (Table 5 A mean of means = 2.0917 overall RSD = 1.27%) than without the use of the internal reference (Table 5 B mean of means = 1.993 overall RSD = 7.18%). There was a significant difference in the pre- cision of the internally referenced and non-referenced data sets (> 99% confidence RSD = 1.27 and 7.18% respectively) and the means also differed significantly from each other (>!@YO confidence 2.09 17 and 1.993). The internally referenced 235U 238U isotope ratio is indistinguishable from the mass spectral result.The use of LA-ICP-AES is a viable method for the determi- nation of the 235U:238U isotope ratio in U-Zr alloys; the use of an intrinsic internal standard (e.g. Zr) is essential if accurate results are to be obtained. The precision of the LA-ICP-AES method is poorer than the determination using con- ventional pneumatic nebulization ICP-AES but is much more rapid. An obvious means of improving the precision of both the conventional and LA determination would be the use of an array detector. This would allow the simul- taneous detection of the isotopically split emission line and improve the sampling statistics by averaging a number of integrations. CONCLUSION The determination of the 235U 238U isotope ratio in U-Zr alloys by ICP-AES has been shown to be accurate precise and rapid.The use of an intrinsic internal standard was shown to be desirable and a small negative bias in the measured isotope ratios was eliminated by the application of an empirical correction factor derived from the 235U 238U emission ratios of a number of U isotope certified reference materials. Precisions of < 0.3% RSD were obtained for conventional sample introduction methodologies utilizing pneumatic nebul- Table 5 U isotope measurements by LA-ICP-AES (Mk. I11 fuel 67% 235U enrichment) A. U signals normalized with respect to Zr emission- Standard Mean deviation RSD(%) n 2.092 0.023 2.107 0.030 2.072 0.014 2.097 0.025 1.09 6 1.40 9 0.70 6 1.20 6 Result by mass spectrometry = 2.094 & 0.0005 B. U signal not normalized- Standard Mean deviation RSD(%) 1.916 0.131 2.085 0.149 1.908 0.1 17 2.062 0.063 6.84 7.15 6.13 3.06 n Result by mass spectrometry = 2.094 L- 0.0005 ization.Laser ablation ICP-AES demonstrated poorer pre- cision than the conventional ICP-AES system (1.4-0.7% RSD) but requires minimal sample preparation. The isotope ratios obtained using ICP-AES agree within experimental uncer- tainty with values derived from TIMS. This method has been shown to complement the more precise mass spectrometric met hods. Argonne National Laboratory is operated for the US Department of Energy by the University of Chicago. This work was supported by the US Department of Energy Reactor Systems Development and Technology under contract W-31- 109-ENG-38. Dr. Martin Edelson of Ames Laboratory is gratefully acknowledged for the loan of the THR 1500 spectrometer.The spectrometer was purchased through funds provided by the Office of Safeguards and Security US Department of Energy. The TIMS determination of the U isotope composition of the U-Zr alloys was performed by M. Michlik (Analytical Laboratory Argonne National Laboratory-West). REFERENCES 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Maeck W. J. Kussy M. E. Morgan T. D. Rein J. E. and Laug M. T. Nucleonics 1962,. 20 80. Begley I. S. and Sharp B. L. J. Anal. At. Spectrom. 1994 9 171. Reed N. M. Hutton R. C. and Marriot P. paper presented at the European Winter Conference on Plasma Spectrochemistry Cambridge UK 1995. Kuhn H. H. Atomic Spectra Longman Green London 2nd edn. 1969. Helig K. Spectrochim. Acta Part B 1977 32 1. King W. H. Isotope Shifis in Atomic Spectra Plenum Press New York 1984. Edelson M. C. and Fassel V. A. Anal. Chem. 1981 53 2345. Edelson M. C. and Fassel V. A. Proceedings of the Third ESARDA Symposium on Safeguards and Nuclear Materials Management Karlsruhe May 6-8 1981 p. 97. Douglas J. High-Resolution Inductively Coupled Plasma Atomic Emission Spectrophotomt?tric Analysis of PUREX Head-End Solutions Westinghouse Hanford Company Report No. WHC- EP-0339 Richland MA 1990. Edelson M. C. DeKalb E. L. Winge R. K. and Fassel V. A. Spectrochim. Acta Part B 1986 41 475. Edelson M. C. in Inductively Coupled Plasmas in Analytical Atomic Spectrometry eds. Montaser A. and Golightly G. W. 2nd edn. VCH New York 1992 p. 341. Vera J. A. Murray G. M. Weeks S. J. and Edelson M. C. Spectrochim Acta Part B 1991 46 1689. Rossi G. and Mol M. Spectrochim. Acta Part B 1969 24 389. Edelson M. C. and DeKalb E. L. in Proceedings of the Ninth ESARDA Symposium on Safeguards and Nuclear Materials Management ed. Stanchi L. Office for Official Publications of the European Communities Luxembourg 1987 vol. XVI p. 107. Goodall P. Johnson S. and Wood E. Spectrochim. Acta Part B 1995 in the press. Myers S. A. and Tracey D. H. Spectrochim. Acta Part B 1983 38 1227. Paper 5/03960F Received June 19 1995 Accepted August 15 1995 60 Journal of Analytical Atomic Spectrometry January 1996 Vol. 1 1

ISSN:0267-9477    

DOI:10.1039/JA9961100057

出版商:RSC    

年代:1996

数据来源: RSC

摘要:

Determination of Selenium in Blood Serum by Hydride Generation Inductively Coupled Plasma Mass Spectrometry Journal of Analytical 1 Atomic I Spectrometry 1 I 1 MARGARET P . RAYMAN FAD1 R. ABOU-SHAKRA AND NEIL I. WARD ICP-MS Facility Department of Chemistry University of Surrey Guildford Surrey U K G U2 5 X H Continuous flow hydride generation inductively coupled plasma mass spectrometry (ICP-MS) was used for the determination of selenium in blood serum. The connector between the spray chamber and the ICP torch was replaced by a Y-piece which allowed the hydride gases to be mixed with argon (fed through the nebulizer and spray chamber) before arriving at the plasma. The performance of the system was optimized with and without introduction of water to the nebulizer (wet and dry plasma).The dry plasma offered high short-term signal stability with the relative standard deviation approaching statistical limits. This was not the case for the wet plasma but the latter demonstrated higher sensitivity and when combined with internal standard correction good long- and short-term stability. The influence of iron and copper on the selenium signal was evaluated and showed no significant effect at the levels expected in serum. In order to achieve acceptable accuracy special attention was paid to the choice of digestion procedure. Good precision (2.27% relative standard deviation) was obtained on nine separate analyses of a quality control blood serum. Analysis of second generation human blood serum reference material and of three different quality control blood serum samples gave results within two standard deviations of the means a negative bias being observed in all cases.Possible explanations of this bias are discussed. Keywords Inductively coupled plasma mass spectrometry; hydride generation; selenium; blood serum The essential trace element selenium has attracted increasing attention in recent years as evidence for its involvement in human health has become apparent. Selenium deficiency has been implicated in the development of severe and fatal cardi- omyopathy (Keshan Disease)' and of osteoarthropy (Kashin-Beck D i ~ e a s e ) . ~ ? ~ Low selenium levels have also been found in many disease states including various forms of c a n ~ e r ~ - ~ acute myocardial infarction,*.' severe rheumatoid arthritis," cirrhosis of the liver'' and conditions exhibiting a compromised immune response.12 Selenium is believed to exert its protective effect by a number of mechanisms the best known of which is as an anti-oxidant and constituent of the peroxide-scavenging enzyme glutathione peroxidase.With increasing recognition of the role of anti-oxidants in disease prevention the need for accurate determination of selenium status has become more important. The determination of selenium in blood serum by conven- tional nebulizer inductively coupled plasma mass spectrometry (ICP-MS) is hampered by spectroscopic interferences on all of the selenium isotopes (Table 1). In addition owing to a high first ionization energy of 9.75 eV the degree of ionization of selenium in the plasma is only about 30%,13 thus the sensitivity of ICP-MS for selenium is relatively low.As a result a low dilution factor is required in order to achieve a reasonable signal. In this particular matrix however this introduces the risk of non-spectroscopic interferences owing to the high levels of analytes such as sodium. The use of hydride generation for the introduction of sel- Table l Spectroscopic interferences on selenium in ICP-MS Isotope (abundance) Interferent 74Se (0.9%) 74Ge-38Ar36Ar 76Se (9.0%) 76Ge-40Ar36Ar 77Se (7.6%) 40Ar37C1 78Se (23.6%) 78Kr-40Ar38Ar 80Se (49.7%) 40Ar40Ar 82Se (9.2%) 82Kr enium into the plasma can significantly enhance the sensitivity by improving the sample delivery rate. In addition hydride generation ICP-MS (HG-ICP-MS) provides chemical separa- tion of selenium from other matrix components thus reducing both spectroscopic and non-spectroscopic interferences.However sample preparation is critical for the accurate deter- mination of selenium by hydride generation. Organic selenium compounds such as selenomethionine selenocysteine and the trimethylselenonium ion found in blood serum which are resistant to acid digestion must be completely decomposed and any selenate (SeV') present reduced to selenite (Se") for the conversion to hydrogen selenide to take place.14 Loss of volatile selenium compounds during such a necessarily vigorous procedure must not however be allowed to occur. In the present study a commercially available hydride gener- ator has been coupled to an ICP-MS instrument.An evaluation of the system is presented and the optimal conditions for its operation reported. The technique has been successfully applied to the determination of selenium in blood serum following digestion by a procedure which addresses the problems out- lined above." Substantial improvement in sensitivity indicates the potential value of the method for the determination of selenium in blood serum and other tissues even in deficiency states. EXPERIMENTAL Instrumentation The investigations described in the present paper were conduc- ted on a Finnigan MAT SOLA ICP-MS instrument (Finnigan MAT Heme1 Hempstead UK). A standard ICP set-up consisting of a concentric nebulizer a water cooled Scott-type spray chamber and a Fassel-type torch was used. However the elbow connecting the exit of the spray chamber into the back of the torch was replaced with a Y-piece in order to introduce the hydride gases (Fig.1). These gases were produced using a GBC HG-3000 continuous flow hydride generator (GBC Scientific Equipment Guildford UK). The uptake rates of the system were 10cm3 min-' for the samples 1.8 cm3 min-' for the hydrochloric acid and 2 cm3 min-' for the sodium tetrahydroborate solution. Serum samples were digested in 100 cm3 glass tubes (31 cm long) that were heated in a Tecator digestor (Perstop Analytical Maidenhead UK) which consisted of an insulated aluminium block with 12 sample positions. The temperature Journal of Analytical Atomic Spectrometry January 1996 Vol. 11 (61 -68) 61To the 4 - ICP / NaBH. (2 cm' min ') HCI ( I 8 c m ' m i n ' ) Sample (Iocm'min ' ) Fig. 1 Schematic diagram of the hydride generation set-up of the block was accurately controlled by a programmable Tecator Autostep 1012 Controller.Only the bottom 7cm of the tubes were within the block thus allowing the remainder of each tube to act as an air condenser for volatile substances. Running Conditions Scan parameters were 8ms dwell time 16 channels per m/z value and 50 passes per scan. The resolution was adjusted to be 0.8 m/z peak width at one tenth of the peak height. Other settings such as nebulizer flow rate and incident power were investigated in the study. Selenium-82 was chosen as the isotope to monitor having the least-important spectroscopic interferences. Krypton an impurity in the argon gas was monitored at m/z 83 in order to correct for the krypton contribution to the m/z 82 signal.Reagents Nitric acid (69% m/m) sulfuric acid (98% m/m) and hydro- chloric acid (35% m/m) were of Aristar quality (Merck Poole UK) except where otherwise stated. Perchloric acid (70% m/m) and sodium hydroxide pellets (Fisons Scientific Equipment Loughborough UK) were of analytical-reagent grade. Sodium tetrahydroborate reductant solution (0.6% m/v) was freshly prepared by dissolving 6 g of sodium tetrahydroborate pellets (98 % m/m Aldrich Chemicals Gillingham Dorset UK) in 1000 cm3 of a solution containing 6 cm3 of saturated sodium hydroxide. Standard indium solution was prepared by diluting a 1000 pg cm-3 standard solution of indium (Spectrosol Merck) with 0.69% m/m nitric acid.Standard selenium copper(r1) and iron(m) solutions were prepared from 10000 pg cm-3 standard solutions of selenous acid copper(I1) nitrate and iron(II1) nitrate respectively (Fisons Scientific Equipment). Standard iron(n) solution was prepared from analytical reagent grade iron@) sulfate heptahydrate (Fisons Scientific Equipment). Standard blood sera used were frozen (-20°C) quality control liquid serum samples 361 363 and 372 (1993-1994) from the Trace Elements Quality Assessment Scheme of the Robens Institute of Industrial and Environmental Health and Safety (Guildford UK). Lyophilized second-generation human serum certified reference material prepared by Versieck and co-workers (Ghent Belgium) was kindly donated by Professor Luc Moens of Ghent University.De-ionized water (2 18 MS2 cm) obtained from a Milli-Q water purification system (Millipore Watford UK) was used throughout the study. All glassware and poly( propylene) ware used were pre- washed soaked in 7% nitric acid at least overnight and rinsed copiously with de-ionized water. Optimization Hydride generator parameters A 1 0 0 n g ~ m - ~ solution of selenium was introduced to the HG-ICP-MS system. The flow of gas to the mass flow control- ler of the hydride generator was varied and the influence of this flow on the system performance in terms of response and stability was evaluated. Nebulizerflow rate and power Selenium solution (2 dm3) at a concentration of 100 ng cm-3 in de-ionized water was introduced continuously to the hydride generator. The effects of varying the nebulizer flow rate and the plasma incident power on the magnitude and stability of the signal were then evaluated.In the first instance the solution-uptake inlet of the nebulizer was blocked off in order to obtain a dry plasma. Under these conditions the incident power was set to 1.0 kW and the nebulizer flow rate was increased from 0.8 to 1.5 dm3 rnin-' in steps of 0.05 dm3 min-l. This stage was repeated for 1.1 1.2 1.3 1.4 and 1.5 kW power settings. The whole experiment was dupli- cated for a wet plasma where de-ionized water was introduced to the nebulizer at a flow rate of 1 cm3 min-'. Hydrochloric acid concentration Solutions of 1.8 3.6 7.2 18 28.8 and 36% hydrochloric acid were prepared by diluting 36% AnalaR grade hydrochloric acid with the appropriate amounts of de-ionized water to a final volume of 50 cm3.These solutions were separately intro- duced via the acid inlet of the hydride generator in order to evaluate the effect of hydrochloric acid concentration on the signal obtained from a solution containing 100 ng cmP3 of selenium in de-ionized water. The effect of hydrochloric acid concentration on the signal was also evaluated using de-ionized water in place of the selenium solution. Uptake and washout To determine the time required for the detected signal to stabilize a 10 ng cm-3 selenium solution was introduced to the hydride generator. The mass spectrometer was set at m/z 82 and a time-resolved scan was then conducted. Similarly in order to ascertain the time required for the signal to drop down to background levels the selenium solution was replaced with de-ionized water as time-resolved readings were taken.Signal stability Selenium solution (2 dm3) at 10 ng cm-:' in 3.5% hydrochloric acid was made up for introduction to the ICP-MS system via the hydride generator. Standard indium solution at a concen- tration of 10 ng ~ m - ~ was fed into the instrument through the nebulizer in order to use it as an effective internal standard. The selenium solution was pumped continuously through the hydride generator over a period of 3 h during which time sets of ten readings of the 'I2Se and "'In signals were taken every 30 min. Digestion Procedure The method used was that described by Welz et al. with a few minor modification^.'^ The steps followed in the procedure are illustrated in Fig.2. To 0.5 cm3 of serum in a digestion tube 2 cm3 (Welz et aE. used 1 cm3) nitric acid were added. The sample was heated to 140°C over 15 min and maintained there for 25 min. It was then allowed to cool. Concentrated sulfuric acid 0.5 cm3 and perchloric acid 0.2 cm3 were then added. 62 Journal of Analytical Atomic Spectrometry January 1996 Vol. 11/ I 1 o.5 cm3 Serum + cm3 H N O ~ Heat to 140 "C over ~ 15 rnin j / c o o i t; room tempyture ul Hold at 140 "C for 15 min 0.5 crn3 H2S04 + 0.2 crn3 HClO (in long digestion tubes) Heat to 140 "C over 15 min Hold at 140 "C for 15 rnin Heat to 200 "C over 10 min Hold at 200 "C for 15 min Heat to 250 "C over 10 rnin Hold at 250 "C for 15 rnin I I Heat to 31 0 "C over 15 min Hold at 31 0 "C for 20 rnin Cool to room temperature - dd 10 cm3 5.6 mol dm-3 HCI E I Heat to 90 "C over 10 min Hold at 90 "C for 20 min I 1 Allow to cool a Make up to 50 cm3 for ICP-MS Fig. 2 Digestion procedure for blood serum (based on the method of Welz et al.'') The temperature was raised to 140 "C over 15 min and main- tained there for 15 min.It was then increased to 200 "C over 10 min and held there for 15 min. Subsequently it was increased to 250 "C over 10 rnin and held for 15 min. A final increase to 310 "C was achieved over 10 min and the tempera- ture held there for 20 min. The heating block was then allowed to cool to room temperature overnight. A 10cm3 volume (Welz et al. used 20 cm3) of 17.5% hydrochloric acid (approxi- mately 5.6 moll-') was then added to the residual digestion solution. The tubes were heated to 90°C over 10 rnin and this temperature was maintained for 20 min.(This step was carried out in order to reduce any remaining Sev' to Se".) The samples were allowed to cool and then made up to 50cm3 with deionized water in poly (propylene) calibrated flasks. Reagent blanks were prepared using the same procedure. Analysis Procedure Sample solution was pumped continuously to the hydride generator (at a rate of 10 cm3 min-') where it was combined with a flow of 35% hydrochloric acid (at 1.8 cm3 min-l) and of 0.6% sodium tetrahydroborate solution (at 2 cm3 min-I). The hydride gases formed were swept into the plasma in a stream of argon at a flow rate of 30cm3 min-'. Standard indium solution at a concentration of 10 ng cmP3 was fed into the instrument through the nebulizer at a constant rate of 1 cm3 min-' to act as an effective internal standard.The indium flow was not stopped between samples. Reproducibility Nine 0.5 cm3 aliquots of a single blood serum specimen were digested as described above and analysed by HG-ICP-MS. Recovery Recovery was checked in two ways. Firstly to 0.4 cm3 of water in a digestion tube 0.1 cm3 of a standard selenium solution containing 1 pg cm-3 was added. This 0.5 cm3 volume was taken through the digestion and analysis procedure in the same way as a 0.5 cm3 serum sample. The exercise was repeated in a separate digestion run. Secondly to each of two 0.5 cm3 aliquots of standard serum specimen 361,O.l cm3 of a standard selenium solution containing 1 pg ~ m - ~ was added.The digestion and analysis were carried out as for serum alone. Influence of Copper and Iron on the Selenium Signal A series of solutions was made up in 3.5% hydrochloric acid all of which contained selenium at l O n g ~ r n - ~ . These also contained either Cu" Fe" or Fe"' at the following concen- trations 0 0.1 0.2 0.5 1 or 5 pg ~ r n - ~ . These solutions were analysed for selenium. Standard indium solution (10 ng cmP3) was fed in through the nebulizer and the ratio of the 82Se to '''In signals calculated for each concentration. Accuracy Aliquots of 0.5 cm3 of three different standard blood serum specimens were digested and analysed by HG-ICP-MS on different occasions in order to assess the accuracy of the procedure. Specimen 361 was analysed four times specimen 372 five times and specimen 363 thirteen times over a four month period.Three aliquots of lyophilized second-generation human serum certified reference material were digested separ- ately and analysed in order to provide additional accuracy data. RESULTS AND DISCUSSION Optimization Hydride generator parameters Initial experiments carried out using the HG-3000 hydride generator showed that the size of the gas-liquid separator was too small for the present purposes since liquid from the reaction mixture tended to bubble up into the transfer line (Fig. 1) causing blockages reduction in sensitivity and extinc- tion of the plasma. As a result the capacity of the gas-liquid separator was modified by increasing its length to 100mm and its diameter to 30mm while retaining the design of the system. Using this modified separator a smooth flow of gaseous hydrides was achieved. The effect of changing the flow of argon gas (as gauged by the pressure in the line) to the hydride generator is shown in Fig.3. Increasing the flow (pressure) appears to enhance substantially both the stability and the response of the system; therefore for the remainder of Journal of Analytical Atomic Spectrometry January 1996 Vul. 11 63.- 14 1 'fn II +I 6 . - 2 ........................................................................ Fig. 3 Effect of carrier gas pressure on the signal for selenium the study the pressure was maintained at 414 kPa. This accords with the recommendations of the system manufacturers and could be due to improved performance of the mass-flow controller inside the HG-3000 system under such conditions.Nebulizerflow rate and power Several investigators have looked at the complex relationship between the nebulizer flow rate the plasma forward power and the instrumental response for conventional nebulization ICP-MS.16 The general trend is that at a certain power setting the sensitivity versus nebulizer flow rate curve is bell shaped. Increasing the forward power of the plasma results in a shift in the maximum response to a higher flow rate and an increase in the magnitude of this maximum. Although higher nebulizer flow rates and a higher power provide an optimal signal response increased levels of oxides and doubly-charged species are observed under these conditions.Thus for most appli- cations the reported optimal working conditions for nebuliz- ation ICP-MS are around 0.8 dm3 min-' nebulizer flow rate and 1.35 kW forward power. On the other hand the optimal operating conditions for HG-ICP-MS depend on the design of the hydride generator itself and whether the system is run under wet or dry plasma conditions. Based on the data shown in Fig. 4 it is clear that better sensitivity is obtained with a wet plasma than with a dry plasma. Such an observation could be attributed to an improved coupling in the plasma owing to the presence of water vapour. Increasing the incident plasma power leads to the shifting of the optimal response for both plasma conditions towards higher nebulizer flow rates. The sensitivity continues to improve for a wet plasma even up to the maximum investigated power of 1.6 kW whilst for a dry plasma the signal deteriorates sharply for incident powers greater than 1.4 kW giving an optimum at about 1.3 kW.At higher nebulizer flow rates (1.1-1.2 dm3 min-I) the signal in a dry plasma is greater than the signal in a wet plasma. This suggests that part of the energy normally available for atomization and ionization is used to desolvate the increased water loading of the plasma resulting from the improved nebulization efficiency at higher nebulizer flow rates. Furthermore at higher incident powers the response curve for a wet plasma tends to move away from the traditional bell shape. This could be due to the occurrence of possible second- ary discharges under these extreme conditions.As a result of this experiment it was decided to utilize a wet plasma for the determination of selenium by hydride generation ICP-MS. This decision which was based mainly on the observed improvement in sensitivity offers the additional benefit of feeding-in through the nebulizer an internal stan- dard to correct for possible drifts in the plasma conditions during the analysis. Under these conditions the detection limit for selenium which was evaluated as three times the standard deviation of an aqueous blank was 0.04 ng crnp3. 64 Journal of Analytical Atomic Spectrometry January 1996 Hydrochloric acid concentration That increasing the concentration of hydrochloric acid substan- tially improves the response of the system to selenium is clearly shown in Fig.5. Maximum response is achieved using 36% hydrochloric acid with ten-fold improvement over the use of 1.8%. Agterdenbos and Bax reported that the rate of formation of hydrogen selenide (in the absence of metal ion catalysts) is greater than the rate of decomposition of sodium tetrahydro- borate.I7 The rate of decomposition of tetrahydroborate is therefore the rate-limiting step in the formation of hydrogen selenide. Since this is proportional to the hydrogen ion concen- tration,17 it is not surprising that the selenium signal improves with increasing concentration of hydrochloric acid. Apart from the improved response of the system to selenium there are other reasons for preferring the use of hydrochloric acid at its most concentrated. Selenium must be in the +IV oxidation state to be reduced to hydrogen selenide.Hydrochloric acid at molarities above 4.5 mol dm-3 reduces SeV' to Se" with the reduction being complete at 6.5 mol dm-3.'8*'9 Although standards aind samples are intro- duced in the Se" form a higher hydrochloric acid concen- tration could reduce any risk of spontaneous oxidation to Sev' and thence a low result. Furthermore Vijan and Leungl' have reported that higher hydrochloric acid concentrations enhance the formation of chlorocomplexes of metals such as copper thereby eliminating possible interferences from these elements. For the above reasons in the analysis of samples concen- trated hydrochloric acid was used although one should be aware of the following disadvantages firstly the high purity hydrochloric acid necessary to limit contamination is expensive and adds substantially to the overall cost of the analysis; and secondly released acid fumes pose significant risks for the health of the operator and cause corrosion of the instrument. Uptake and wash-out The fact that the selenium signal reaches a stable level approxi- mately 60s from the introduction of the sample solution is shown in Fig. 6(a).The time for the signal to drop down to background level after replacement of the selenium solution by de-ionized water is shown in Fig. 6(b). The decay of the signal is very rapid and stabilizes at the background level after approximately 70 s. The observed initial trough corresponds to the uptake of air into the system as the sample tube is being moved from one solution to the other.It is worthy of note that there is a 20-fold reduction in sensitivity when comparing the data in Figs. 3 and 4 with those obtained in this experiment. The SOLA ICP-MS comes supplied with two detectors a Faraday detector and an elec- tron-multiplier detector. Generally the €araday detector (used in this study for concentrations )10 ng ~ m - ~ e.g. Figs. 3 and 4) is 5-10 fold more sensitive than the electron multiplier although this factor increases as the multiplier ages. This uptake and washout experiment was conducted using an ageing multiplier which resulted in the observed reduction in sensitivity. Stability of the signal Short-term and long-term stabilities of the selenium signal have been evaluated in this study both with and without internal standard correction. Short-term stability evaluated as the relative standard deviation (RSD) of ten determinations varied between 4.5 and '7.1 YO without "'In correction and between 1.5 and 7.7% with '"In correction.For six out of the seven observations taken the use of this correction resulted in improved precision. However these figures are far from the expected 0.35 YO precision calculated from counting statistics VOl. 111.0 kW Power 4500000 4000000 3500000 3000000 2500000 3000000 1500000 1000000 500000 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.1 kW Power 6000000 I - 5000000 I 2000000 0.6 0.7 0.8 0.9 I 1.1 1.2 1.3 6000000 5000000 1 I I - I -+-- O t 0.6 0.7 0.8 0.9 I 1 . 1 1.2 1.3 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 Nebulizer fow rate/dm3 min-’ +Wet Plasma -4- Dry Plasma - 1.2 kW Power 7000000 1 6000000 - 5000000 - 4000000 3000000 - 3oO0oO0 - - IOOOOOO - -~ 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 7000000 6000000 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1OOOOOOO I 1.6 kW Power 2000000 :=I 1000000 O i 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 Nebulizer fow rate/dm3 mh-’ +Wet Plasma +Dry Plasma Fig.4 Effect of plasma power and nebulizer flow rate on the selenium signal in wet and dry plasma conditions (100 divided by the square root of the signal). In order to ascertain the origin of this discrepancy the same experiment was repeated for a dry plasma and the reproducibility based on sets of ten readings was calculated. The results varied between 0.40 and 1.32%. These figures are superior to those observed for a wet plasma and suggest that the difference in stability is caused by the introduction of aerosol to the plasma with its associated desolvation effects noise from the peristaltic pump etc.Over a period of 3 h the signal for selenium tended to drift Journal of Analytical Atomic Spectrometry January 1996 Vol. 11 65q/ 1 - ; 1 0 0 5 10 I5 20 25 30 35 40 96 HC1 Fig. 5 Effect of HCl concentration on the "Se signal ratioed to noise as represented by the 83Kr signal m I 66 - ' 6 4 - 0 f 6 2 - .- CI 6 0 . 5 8 - (II 2 5 6 - E 8 5 4 - * 5 2 . 50000 i i .............................. ......I i 40000 ...................... I 30000 10000 $ 0 .- u) N Starting (b 1 point $ 50000 40000 ' 30000 20000 1 \ I \ loooo t 1.I 1 1 I 0 20 40 60 80 100 120 140 Tirnds Fig. 6 Time-resolved spectra of selenium by HG-ICP-MS (a) uptake and (b) wash-out upwards as shown in Fig.7(a). Close inspection of the indium signal over the same time period revealed the same trend for this element. Indeed it is shown in Fig. 7(b) that by taking the ratio of the signal of s2Se to that of 'I5In a more stable indicator is obtained. Since the indium and selenium are fed separately into the plasma these data suggest that the drift is caused by instabilities in the plasma or the ion optics. Using indium correction the %RSD from the 70 readings taken in 90000 v) +I 80000 - rn ijj 70000 60000 ............................................................... 1 1 1 1 (a ) @ 1.9 1 1 +I 1.8 1.7 # 1.6 1.5 2 1.3 .B - 1.4 2 1.2 0 30 60 90 120 150 180 Timds Fig. 7 Stability of the selenium signal (a) without internal standard correction; and ( 6 ) with indium as effective internal standard the response has been normalized by dividing the "Se by the "'In signal.The solid line represents the mean whilst the broken lines correspond to +1 SD this study dropped from 13.1% (with no "'In correction) to 5.5%. This figure falls within the short-term precision range discussed above and therefore no other 'internal standards' were investigated. Reproducibility The results of nine separate analyses of the same serum specimen are shown in Fig. 8. Selenium concentration ( n g ~ r n - ~ ) is shown as a function of sample number. Reproducibility is excellent with an RSD of 2.3% from the mean of 59.9 ng C M - ~ . All data are within 1.3 standard devi- ations of the mean. Recovery Recovery as determined by the first method (i.e.spike only) was measured as 94.3 and 95.3%. By the second method (k spike + serum) subtraction of the experimentally determined value of the selenium concentration in the serum enabled the recovery to be calculated as 95.2 and 107.5% for the two samples. These recovery figures are satisfactory implying very little loss of selenium. Influence of Copper and Iron on the Selenium Signal Interference from transition metal ions is known to reduce analytical sensitivity in hydride generation," partly by enhanc- ing the decomposition of sodium tetrahydroborate which results in formation of less hydrogen ~e1enide.l~ Since copper and iron are the transition metals present at highest concen- tration in serum the effect of various concentrations of Cu" Fe" and Fe"' on the selenium signal ratioed to indium (fed through the nebulizer) was investigated.It is shown in Fig. 9 that Cu" has no effect until the concentration goes beyond 1 pg C M - ~ a concentration likely to be 100-fold higher than 50 -; 0 1 2 3 4 5 6 7 8 9 10 Sample number Fig. 8 Reproducibility for different determinations of selenium in blood serum 362 3 1.6 i .- $ 1.4 c 1.2 1.0 2 0.6 (I) - In 9 0.8 B 0.4 a . ; 0.2 0 0.1 0.2 0.5 1 5 Concentration tpg cm4 k3 Cu" R Fe"' Fe" Fig. 9 Effect of [Cu"] [FP] and [Fe"] on the selenium signal ratioed to indium 66 Journal of Analytical Atomic Spectrometry January 1996 Vol. 11Table 2 quality control blood serum samples Results of the determination of selenium (in ng cmP3) in Experimental values f B* Serum sample (number of determinations) Reference values k B Specimen 361 24k4 (4) 30+9 Specimen 363 58k6 (13) 62f8 Specimen 372 7659 ( 5 ) 97_+11 * B = Standard deviation.that present in the digested serum solution. It also shows that even at 5 pgcmP3 neither Fe" nor Fe"' has any effect on the selenium signal. Thus it would appear that interference from the major transition metal ions found in blood serum can be ruled out under the experimental conditions used although possible synergistic interferences between transition metal ions and reduced nitrogen oxide species (derived from nitric acid digestion)" have not been excluded. Interferences from other hydride-forming elements such as arsenic and antimony were not investigated owing to the very low levels at which these elements occur in serum.Accuracy (Quality Control) Table 2 shows the results of analysis by HG-ICP-MS following digestion of the three standard serum samples with their reference values for comparison. It can be seen that the experimental values fall well within one standard of deviation of the mean in the case of specimens 361 and 363 and within two standard deviations in the case of specimen 372. Three separate analyses of the second generation human serum certified reference material gave a mean and standard deviation of 0.94f0.03 pg g-' compared with a certified mean and standard deviation of 1.05 kO.10 pg g-'. Analysis of all four standard materials indicates a negative bias in results obtained by hydride generation ICP-MS.Historically the determination of selenium in blood serum by hydride gener- ation has yielded low results.21 The IUPAC commissioned work of Welz et a!." blamed inadequate sample preparation and recommended a digestion method which when followed obviated this systematic error. In the present work the method described by Welz et al. has been used including the final reduction step at 90°C to give Se". Despite this it could be that by the time the analysis was carried out some of the selenium was no longer in the +IV oxidation state thus giving a negative bias. A number of worker^'^,^^ have emphasized the need to carry out the analysis within a very short time of the reduction taking place in order to avoid back-oxidation to Sevl according to the following equilibrium H2SeV'04 + 2HC1+ AH = H2SeIVO3 + C12 + H20 ( 1) Since the reaction is endothermic from left to right,24 the formation of SeIV is favoured by raising the temperature while the back oxidation to SeV1 which is virtually not hindered kinetically can readily occur as the solution cools to room temperature.The digestion tubes used were open to the air therefore virtually all of the chlorine formed from the oxidation of HCl would be expected to be driven off thus preventing substantial occurrence of the back-reaction. However this would not be the case for bromine formed in an analogous manner to chlorine from bromide present as an impurity (ca. 50 pg g-') in the hydrochloric acid used for the reduction. Bromine is known to carry out the reverse reaction i.e.the conversion of selenous to selenic acid." Since bromine is a liquid (b.p. 58.8 "C) and moderately soluble in water (without significant disproportion to HOBr26) it possibly would not all escape from the digestion tubes which are only heated to 90 "C. On cooling the residual bromine will drive the reaction in the reverse direction thus reducing the amount of SeIV available for hydride generation. Alternatively bromide could behave as iodide which is known to reduce Se" to elemental selenium according to the following equation:27 H2Se0 + 4H' + 41- = Se(s) + 212 + 3Hz0 (2) In either case a low result would be obtained. Experiments are underway to investigate the validity of these suggestions and the possibility that a speedy dilution of the warm reduction solution by lowering the concentration of any species likely to react with SeIV would reduce the risk of negative bias in the results. CONCLUSION Hydride generation ICP-MS is a highly sensitive method for the determination of low levels of selenium.The method has been successfully applied to the analysis of blood serum. The parallel introduction of a standard solution through the nebulizer offers a means of correcting for instrumental drift. This set-up also has the added possibility of simultaneous introduction of the sample through both the nebulizer and the hydride generator allowing for the determination of non- hydride-forming elements at the same time. This offers scope for future investigation bearing in mind possible spectral interferences from the digestion acids.In our optimized system we obtained a detection limit of 0.04 ng ~ m - ~ . This compares favourably with other analytical methods. Quality control blood serum was analysed with good reproducibility. The concentration of selenium in four different reference blood sera was determined and gave results within one or two standard deviations of the respective means. However the fact that all our data were on the low side suggests a negative bias in the method which is being investigated. The authors are grateful to Dr. Andrew Taylor of the Robens Institute for use of the Tecator Digestor and for supplying serum samples; also to Professor Luc Moens of the University of Ghent for supplying the second generation blood serum reference material. M.P.R. is the holder of a Daphne Jackson Memorial Fellowship funded jointly by the Leverhulme Trust Scotia Pharmaceuticals and the University of Surrey.REFERENCES 1 2 3 4 5 6 7 8 9 10 Chen X. Yang G. Chen J. Chen X. Wen Z. and Ge K. Biol. Trace Elem. Rex 1980 2 91. Yang G. Ge K. Chen J. and Chen X. World Rev. Nutr. Diet. 1988 55 98. Chong-Zheng L. Jing-Rong H. and Cai-Xia L. in Selenium in Biology and Medicine eds. Combs G. F. Spallholz J. E. Levander 0. A. and Oldfield J. E. Van Nostrand Reinhold New York 1986 p. 934. Willet W. C. Morris J. S. Pressel S. Taylor J. O. Polk B. F. Stampfer M. J. Rosner B. Schneider K. and Hames C . G. Lancet 2 1983 130. Jaskiewicz K. Marasas W. F. O. ROSSOUW J. E. Van Niekerk F. E. and Heine E. W. P. Cancer 1988 62 26. Clark L. C. Graham G. F. Crounse R.G. Grimsonc R. Hulka B. and Shy C. M. Nutr. Cancer 1984 6 13. Pawlowicz Z. Zachara B. A. Trafikowska U. Maciag A. Marchaluk E. and Nowicki A J. Trace Elem. Electrolytes Health Dis. 1991 5 275. Salonen J. T. Alfthan G. Huttunen J. K. Pikkarainen J. and Puska P. Lancet 2 1982 175. Kok F. J. Hofman A. Witteman J. C. M. de Bruijn A. M. Kruyssen D. H. C. M. de Bruijn M. and Valkenburg H. A. J. Am. Med. Assoc. 1989 261 1161. Tarp U. Overvad K. Hansen J. C. and Thorling E. B. Scand. J. Rheumatol. 1985 14 97. Journal of Analytical Atomic Spectrometry January 1996 Vol. 11 6711 12 13 14 15 16 17 18 19 20 21 Aaseth J. Alexander J. Thomassen Y. Blomhoff J. P. and Skrede S. Clin. Biochem. 1982 15 281. Dworkin B. M. Rosenthal W. S. Wormser G. P. and Weiss L. J. Parenter. Enteral Nutr. 1986 10 405. Houk R. S. Anal. Chem. 1986 58,97A. Welz B. and Melcher M. Anal. Chim. Acta 1984 165 131. Welz B. Wolynetz M. S. and Verlinden M. Pure Appl. Chem. 1987 59 927. Vanhaecke F. Vandecasteele C. Vanhoe H. and Dams R. Mikrochim. Acta 1992 108,41. Agterdenbos J. and Bax D. Anal. Chim. Acta 1986 188 127. Vijan P. N. and Leung D. Anal. Chim. Acta 1980 120 141. Buckley W. T. Budac J. J. Godfrey D. V. and Koenig K. M. Anal. Chem. 1992 64 724. Brown R. M. Fry R. C. Moyers J. L. Northway S. J. Denton M. B. and Wilson G. S. Anal. Chem. 1981 53 1560. Ihnat M. Wolynetz M. S. Thomassen Y. and Verlinden M. Pure Appl. Chem. 1986,58 1063. 22 Hill S. J. Pitts L. and Worsfold P. J. Anal. At. Spectrom. 1995 10 409. 23 Tiran B. Tiran A. Rossipal E. and Lorenz O. J. Truce Elem. Electrolytes Health Dis. 1993 7 211. 24 Krivan V. Petrick K. Welz B. and Melcher M. Anal. Chem. 1985,57 1706. 25 Barnett E. de B. and Wilson C. L. Inorganic Chemistry Longmans Green London 1957. 26 Cotton F. A. and Wilkinson G. Advanced Inorganic Chemistry John Wiley New York 1988 p. 565. 27 Ericzon C. Pettersson J. and Olin A. Talunta 1990 37 725. Paper 5/04004C Received June 21 1995 Accepted September 14 1995 68 Journal of Analytical Atomic Spectrometry January 1996 Vol. 11

ISSN:0267-9477    

DOI:10.1039/JA9961100061

出版商:RSC    

年代:1996

数据来源: RSC

摘要:

Determination of Atmospheric Trace Metal Concentrations by Isotope Dilution Inductively Coupled Plasma Mass Spectrometry after Separation from Interfering Elements by Solvent Extraction TAKUNORI KATOH MASAYUKI AKIYAMA AND HIDEYUKI OHTSUKA Hokkaido Institute of Environmental Sciences Kita-ku Sapporo 060 Japan SEIJI NAKAMURA Muroran Institute of Technology Muroran 050 Japan KENSAKU HARAGUCHI Hokkaido National Industrial Research Institute Sapporo 062 Japan KUNI H I KO AK AT SUK A* Kitami Institute of Technology Kitami 090 Japan An isotope dilution ICP-MS method for the determination of six elements (Ni Cu Zn Cd TI and Pb) in atmospheric particulate samples is described. The method involves a complexation/solvent extraction step to separate these elements from potentially interfering elements prior to ICP-MS analysis.Accuracy of the method was demonstrated by analysis of a Vehicle Exhaust Particulates CRM. The method was successfully applied to the analysis of atmospheric particulates collected in a remote mountainous area of Hokkaido Island Japan. Keywords Isotope dilution inductively coupled plasma mass spectrometry trace metals atmospheric particulates solvent extraction The measurement of atmospheric concentrations of metals is gaining importance as the pollution of the atmosphere is growing world-wide. As samples of filter-collected atmospheric particulate matter are usually very small (ranging from several to a few tens of milligrams) a very sensitive analytical method is required to analyse them for background levels of trace metals.'-' Isotope dilution (ID) ICP-MS has become the preferred method of elemental McLaren et aL6 discussed the advantages of ID ICP-MS where elemental concentrations are determined by measurement of an isotope ratio rather than an absolute ion intensity.A great advantage of ID ICP-MS over other types of ICP-MS analyses is that its accuracy is not degraded by multiplicative interferences such as matrix suppression and isotope ratios are less affected by instrumental drift than are ion sensitivities. However additive-type inter- ferences such as spectroscopic overlaps can degrade the accu- racy of ID ICP-MS. The multi-element analysis of atmospheric particulate matter samples with ICP-MS particularly the determination of Ni Cu and Cd by an isotope dilution method can be complicated because of isobaric interferences on several of their most abundant isotopes by polyatomic species i.e.the interference * To whom correspondence should be addressed. Journal of Analytical Atomic Spectrometry of 40Ar180 and 40Ca'80 on 58Ni 44Ca160 on 60Ni and 40Ar23Na and 47Ti160 on 63Cu respectively. When Cd concen- trations are very low Sn MOO and MoOH may contribute significantly to the ion signals measured at m/z 110 111 112 113 114 and 116. Hence the prior separation of the trace metals from these matrix elements is necessary. In this paper an ID ICP-MS method is presented for the determination of concentrations of trace metals (Ni Cu Zn Cd T1 and Pb) in atmospheric particulates collected monthly from November 1989 to October 1990 in a mountainous area of Hokkaido Island (Hidaka Japan).Solvent extraction with dithizone was found to reduce the levels of interfering matrix elements adequately taking advantage of the high extractability of the heavy metal ions and the low affinity of Mo Sn V Ti and alkali and alkaline earth elements. The aim of this work was to evaluate the applicability of an ID ICP-MS method for the determination of total Ni Cu Zn Cd TI and Pb in airborne particulate samples after clean-up of dissolved samples by solvent extraction with dithizone. EXPERIMENTAL Apparatus A standard Model PMS-2000 inductively coupled plasma mass spectrometer (Yokogawa Analytical Systems Tokyo Japan) was used. The instrument was operated at an rf power setting of 1.2kW. The argon plasma gas flow was set 141min-'.Auxiliary gas flow and nebulizer gas flow were 0.5 and 0.8 1 min-l respectively. A sampler and skimmer both made of copper with orifice diameters of 1 and 0.5 mm respectively were employed. Sample solution was introduced by using a peristaltic pump which is standard equipment for the PMS-2000 at a delivery rate of about 0.5mlmin-' to the nebulizer. Airborne particulate matter samples were collected with a low-volume air sampler (Shintaku Amagasaki Japan). Reagents All high-purity acids ammonia solution and chloroform were prepared by sub-boiling distillation of analytical-reagent grade Journal of Analytical Atomic Spectrometry January 1996 Vol. 1 1 (69-71) 69reagents in quartz and Teflon stills. Doubly distilled water (DDW) was prepared by sub-boiling distillation of distilled water feedstock in quartz stills.Dithizone was purified by recrystallization from chloroform. Stable isotope-enriched spikes for the elements were pur- chased from the Oak Ridge National Laboratory (Oak Ridge TN USA). Stock solutions of the spikes were prepared by dissolving them in HNO or aqua regia followed by dissolution in 1 moll-' HN03 and their concentrations were checked by reverse spike ID ICP-MS. Samples Airborne particulate matter samples were collected on cellulose nitrate membrane filters (0.8 pm pore size; 47 mm diameter filter) at Hidaka (Hokkaido Japan) for 30 d with a low-volume air sampler. This sampler has a cyclone-type classifier which rejects particles larger than 10 pm in diameter. The sampling flow rate used was 20 1 min-'.The filter was kept at 20 "C for 2 d in an air-conditioned clean-room prior to weighing the filter without and with the aerosol sample. A Vehicle Exhaust Particulates CRM (NIES No. 8 National Institute for Environmental Studies Ibaraki Japan) was also used to check the accuracy of analyses. Digestion of the Sample Filter and Procedure The filter was folded and placed in a Teflon beaker. Appropriate amounts of enriched stable isotopes of the elements were added to the beaker for isotope dilution analysis and then 10ml of HNO and 5 ml of HC104 were added. The beaker was heated on a hot-plate at 200"C covered with a Teflon watch-glass. After the solution had clarified 2 ml of HF were added to the beaker and the mixture was re-digested on a hot-plate at 200°C until dry.The dried residue was subsequently re-dissolved in 2 ml of 1 + 1 HNO and made up to a volume of 20 ml. The sample solution was placed in a separating funnel after adjustment of the pH to 2. Then 30ml of 0.003% dithizone in chloroform were added. The mixture was shaken for 5 min to extract Cu into the chloroform layer. The aqueous phase was re-adjusted to pH 9 with ammonia solution and the mixture was again shaken for 5min. At this stage all of the elements (Cu Ni Zn Cd T1 and Pb) were extracted into the chloroform layer. The chloroform layer was then transferred into another separating funnel and 10 ml of 1 + 1 HNO were added to the funnel. The mixture was shaken for 5min to back-extract the elements into the aqueous phase. After the phases had been allowed to separate the aqueous phase was transferred into a Teflon beaker and 0.2ml of HC10 was added to the beaker. The solution was heated on a hot-plate at 200 "C until dry.The dried residue was re-dissolved in 0.5 ml of 1 + 1 HN03 and diluted with 10 ml of DDW. About 150 mg of the Vehicle Exhaust Particulates CRM (NIES No. 8) were digested and subsequently extracted by the same procedure. Blanks were prepared by carrying out the above procedure after the addition to the Teflon beaker in which the blank- filter was placed of enriched isotope spikes equivalent to one- tenth of the amounts added to the samples. Nickel Cu Zn Cd T1 and Pb were determined by ID ICP-MS using the following reference/spike isotope pairs 60Ni/61Ni; 63Cu/65Cu; 66Zn/68Zn; 111Cd/116Cd; 205Tl/203Tl; and 208Pb/206Pb.Weighed amounts of the spike solutions were added by means of adjustable micropipettes. In this work checks for mass discrimination were made with 50 pg1-l natural abundance solutions of each of the elements of interest as described in ref. 6. RESULTS AND DISCUSSION The described method for the collection of aerosol samples was first employed in 1988 in a mountainous area of Hidaka (Hokkaido Japan) about 100 km south-east of Sapporo in order to study the seasonal variability of atmospheric trace metal concentrations and to compare the data with those collected at Sapporo. During a 6 month experiment the amount of aerosol sample collected on each filter was in the range 4-15 mg when air was sampled at 20 1 min-l for 30 d.The aerosol samples contained levels of the trace analytes ranging from several tens of nanograms (Cd and T1) to several micrograms (Cu Zn and F'b) and much higher levels of Na Mg Al Ca Fe and Ti. Thus the prior separation of the trace metals from major matrix elements was necessary to perform ID ICP-MS analysis because of isobaric interferences by polyatomic ions of CaO CaOH ArNa and T i 0 on 60Ni 61Ni 63Cu and 65Cu. As concentrations of Cd in the samples are very low MOO and Sn probably affect the ratio of '"Cd 'I6Cd measured. When concentrations of Cr and V which mainly originate from anthropogenic emissions are high 51V160H and 52Cr160 may contribute significantly to the ion signals of Zn measured at m/z 68. Although solvent extraction with dithizone is a well estab- lished method and the metals that react with dithizone have been summarized by Sandell,' separation of the analytes from the major matrix elements of the sample was examined under the present extraction conditions.The recovery of all the analytes was greater than 99% except for Cd for which the Table 1 with dithizone extraction Recoveries of the matrix elements by the present procedure Element Recovery (%)* Element Recovery (%)* Ca 0.2f0.1 Mo 0.010 k 0.005 Mg 0.03 k 0.02 Sn'" 1.9k0.5 0.3 kO.1 Na 1.0k0.6 V Cr 0.1 1 k 0.04 Ti 1.8f0.7 *The procedure was carried out using 20ml of aqueous phase containing 1 mg of Ca Mg and Na and 200 pg of Cr Mo Sn V and Ti respectively. Table 2 Absolute blanks and total procedural blanks of the present method Element Absolute blank/ng Total procedural blank/ng m- 3* Ni 22.6 f 2.1 0.045 & 0.004 c u 9.3 f 0.7 0.049 f 0.004 Cd 0.21 f 0.04 0.00027 & 0.00005 T1 < 0.05 < 0.00005 Pb 0.82 f 0.05 0.0041 f 0.0002 Zn 9.0 f 0.05 0.18 kO.01 * The value was obtained by dividing the total blanks including the filter by the total flow-rate of sample collection.Table3 (NIES No. 8) ID ICP-MS analysis of Vehicle Exhaust Particulates CRM This work Element Found/pg Concentration/pg g - Ni 2.99 & 0.025* 19.4 f 0.19 c u 10.4k0.15 67.7 & 1.0 Zn 160f1 1040f 10 Cd 0.163 f0.002 1.06 f 0.02 T1 0.022 & 0.001 0.15 f 0.001 Pb 32.3 & 0.3 210f2 Certified value/pg g-' 18.5 f 1.5 67+3 1040 f 50 1.1 kO.1 (0.17)+ 219k9 * Precision expressed as the standard deviation (n = 5). Value for T1 is not given by NIES.The value was obtained by Seiji Nakamura with ID SIMS. 70 Journal of Analytical Atomic Spectrometry January 1996 VoE. 11Table 4 Determination of atmospheric trace metal concentrations at Hidaka (Japan) by ID ICP-MS multi-element analysis Found*/ng m-3 Run No. 1 2 3 4 5 6 7 8 9 10 11 12 Period November 1989 December 1989 January 1990 February 1990 March 1990 April 1990 May 1990 June 1990 July 1990 August 1990 September 1990 October 1990 Aerosol/pg rnp3 5.4 4.6 4.3 8.1 8.2 10.2 11.6 9.8 7.6 6.9 5.0 6.1 Ni 0.32 0.31 0.37 0.79 0.46 0.51 0.64 0.51 0.20 0.26 0.35 0.25 c u 0.52 0.82 0.72 1.6 1.7 1.3 1.4 1.7 1.8 I .2 0.89 1 .o Zn 6.2 5.9 5.4 9.2 9.0 9.3 9.6 8.8 3.9 3.8 3.3 4.4 Cd 0.09 1 0.07 1 0.056 0.1 1 0.11 0.12 0.12 0.1 1 0.050 0.046 0.040 0.053 T1 0.020 0.02 1 0.018 0.026 0.025 0.020 0.035 0.030 0.017 0.01 1 0.041 0.012 Pb 4.5 4.1 2.1 4.8 6.2 5.7 7.0 6.2 3.0 2.3 2.4 2.5 *Blank value is subtracted.recovery was 96+2% whereas the recoveries of the matrix elements were less than 2% as shown in Table 1. As the organic matter in the aqueous phase after the back-extraction procedure is destroyed completely by heating with a few drops of concentrated HC10,,9 the precision of the ID ICP-MS analysis was less than 3% relative standard deviation (n = 5). Table 2 shows the absolute blanks obtained by the present method not including the contribution from the filter. As the filters used in this work contained relatively high amounts of Ni Cu and Zn the total procedural blanks including the filter were measured separately by the ID ICP-MS method.Typical values of these are also shown in Table 2. The analytical results for the NIES No. 8 CRM Vehicle Exhaust Particulates summarized in Table 3 resulted from five independent determinations. The accuracy of the method is evident from a comparison of the results with the certified values. The airborne particulate samples collected from Hidaka (Japan) were analysed by the proposed ID ICP-MS method. The analytical results obtained after total decomposition and extraction with dithizone followed by back-extraction with HNO are shown in Table 4. The results indicate that baseline levels of atmospheric trace elements can be determined with good precision. Detection limits ranged from 0.15 pg m-3 for Cd to 30pgm-3 for Zn based on three times the standard deviation of the blanks.Finally it is interesting to compare the values obtained during the periods February-May and July-October; the values obtained during February-May were higher than those obtained during July-October for all the elements measured with the exception of TI. The authors thank J. W. McLaren (National Research Council of Canada Ottawa) for helpful comments during the prep- aration of this manuscript. REFERENCES Duce R. A. Hoffman G. L. and Zoller W. H. Science 1975 187 59. Mukai H. Ambe Y. and Morita M. J. Anal. At. Spectrom. 1990 5 75. Dick A. L. Geochim. Cosmochim. Acta 1991 55 1827. Berg T. Royset O. and Steinnes E. Atmos. Environ. 1993 27A 2435. Akatsuka K. Hoshi S. McLaren J. W. and Berman S. S. Bunseki Kagaku 1994 43 61. McLaren J. W. Beauchemin D. and Berman S. S. Anal. Chem. 1987 59 610. McLaren J. W. Mykytiuk A. P. Willie S. N. and Berman S. S. Anal. Chem. 1985 57 2907. Akatsuka K. McLaren J. W. Lam J. W. and Berman S. S. J. Anal. At. Spectrom. 1992 7 889. Sandell E. B. Colorimetric Determination of Traces of Metals Interscience New York 2nd edn. 1950 pp. 90-100. Paper 51041 240 Received June 26 1995 Accepted October 27 1995 Journal of Analytical Atomic Spectrometry January 1996 Vol. 11 71

ISSN:0267-9477    

DOI:10.1039/JA9961100069

出版商:RSC    

年代:1996

数据来源: RSC

摘要:

Abou-Shakra Fadi R. 61 Akatsuka Kunihiko 69 Akiyama Masayuki 69 Beato Emilio Romero 37 Blades M. W. 43 Chenery Simon 53 Cordero Bernard0 Moreno 37 Efstathiou Constantinos E. 31 Fang Zhaolun 1 JANUARY 1996 Flint Colin D. 53 Garcia Sanchez Soledad 37 Goodall Phillip S. 57 Haraguchi Kensaku 69 Johnson Stephen G. 57 Katoh Takunori 69 Knight Kevyn 53 Nakamura Seiji 69 Ohtsuka Hideyuki 69 Parsons Patrick J. 25 Perez Pavon Jose Luis 37 Pinto Carmelo Garcia 37 Piperaki Efrosini A. 31 Polydorou Christoforos K. 31 Rayman Margaret P. 61 Slavin Walter 25 Tao Guanhong 1 Thomaidis Nikolaos S. 31 Thompson Michael 53 Ward Neil I. 61 Weir D. G. 43 Xu Shukun 1 Zochowski Stan W. 53 Zong Yan Y. 25 Journal of Analytical Atomic Spectrometry January 1996 Vol. 11 (73) 73

ISSN:0267-9477    

DOI:10.1039/JA9961100073

出版商:RSC    

年代:1996

数据来源: RSC

摘要:

JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY INSTRUCTIONS TO AUTHORS The Journal of Analytical Atomic Spectrometry (JAAS) is an international journal for the publication of original research papers communications and laboratory notes concerned with the development and analytical application of atomic spectrometric techniques. The journal is published monthly and also includes comprehensive reviews on specific topics of interest to practising atomic spec- troscopists and incorporates the Atomic Spectrometry Updates (ASU) literature reviews. Additional Special Conference Issues are also published. Manuscripts intended for publication as papers or communications must describe original work related to atomic spectrometric analysis. 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Authors are particularly asked to quote this number on all subsequent correspondence. All papers (including conference presentations submitted for special issues) are sent simultaneously to at least two referees whose names are not disclosed to the authors.On the basis of the referees’ reports the Managing Editor decides whether the paper is suitable for publication either unchanged or after appro- priate revision. This decision and relevant comments of the referees are communi- cated to the author. Differences of opinion are mediated by the Managing Editor possibly after consultation with further referees or by the Editorial Board. When rejection of a paper is recommended the Managing Editor informs the author and returns the top copy of the manuscript. Authors have the right to appeal to the Editorial Board if they regard a decision to reject as unfair.Authors will receive formal notification when papers are accepted for publication. Proofs. 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The recommended order of presentation is as indicated below Title. This should be as brief as is consistent with an adequate indication of the original features of the work. The title should usually include the analyte being determined or identified the matrix and the analytical method used. Summary. A summary of about 250 words giving the salient features and drawing attention to the novel aspects should be provided for all papers.It should be essentially independent of the main text and include relevant quantitative information such as detection limits precision and accuracy data. Keywords. Up to eight keywords or key phrases indicating the topics of importance in the work described should be included after the summary. Aim of investigation. A concise introductory statement of the novel features of the work and the object of the investigation with any essential historical background followed if necessary by a brief account of preliminary experimental work with relevant references. 75(e) Description of the experimental procedures. Working details must be given concisely. Analytical procedures should be given in the form of instructions; well known operations should not be described in detail.Suppliers of equipment and materials and their locations should be mentioned. The choice of any optimization procedure (in accordance with some accepted protocol) must be justified and any figure of merit clearly stated. This section should also include information on how a new method was validated including a description of the statistical procedures used. ( f ) Results and Discussion. Results are best presented in tabular or diagram- matic form (but not both for the same results) followed by an appropriate statistical evaluation which should be in accordance with accepted practice. For example a new procedure for multi-element determinations which produced results for which the concentration of 8 out of 10 of the elements determined in a standard reference material were statistically indistinguish- able from the certificate values should be described in those terms and not referred to as ‘excellent agreement’.This is particularly important in the summary. Any discussion should comment on the scope of the method and its validity followed by a statement of any conclusions drawn from the work. A separate conclusions section is not encouraged but if included it sbould ( g ) Acknowledgements. Contributions other than from co-authors companies not simply duplicate statements in the discussion. or sponsors may be acknowledged in a separate paragraph at the end of the paper. Titles may be given but not degrees. References. References should be numbered serially in the text by means of superscript figures e.g.Foote and Delves,’ Burns et a12 or .... in a recent paper ...3 and collected in numerical order under ‘References’ at the end of the paper. They should be listed with all the authors’ names and initials in the following form (double-spaced typing) Sharp B. L. Barnett N. W. Burridge J. C. Littlejohn D. and Tyson J. F. J. Anal. At. Spectrom. 1988 3 133R. Hara H. Horva G. and Pungor E. Analyst 1988 113 1817; Anal. Abstr. 1989 51 6H57. Norwitz G. and Keliher P. N. Analyst 1987 112 903 (and references cited therein). L‘vov B. V. Polzik L. K. Romanova N. P. and Yuzeforskii A. I. J. Anal. At. Spectrom. in the press. OConnor A. Sigma St. Louis MO personal communications 1989. Appelqvist R. Ph.D. Thesis University of Lund Sweden 1987. Journal titles should be abbreviated according to the Chemical Abstracts Service Source Index (CASH).The abbreviation for this journal is J. Anal. At. Spectrom. For books the edition (if not the first) the publisher and the place and date of publication should be given followed by the page number. 1 Harrison W. W. and Donohue D. L. in Treatise on Analytical Chemistry eds. Kolkhoff I. M. and Winefordner J . D. Wiley New York 2nd edn. British Pharmacopoeia 1988 HM Stationery Office London 1988 vol. 1 p. 140. Beauchemin D. and Craig J. M. in Plasma Source Mass Spectrometry. The Proceedings of the Third Surrey Conference on Plasma Source Mass Spectrometry University of Surrey July 16th-l9th 1989 eds. Jarvis K. E. Gray A. L. Jarvis I. and Williams J. G. The Royal Society of Chemistry Cambridge 1990 pp.25-42. OfJicial Methods of Analysis of the Association of OfJicial Analytical Chemists ed. Horwitz W. Association of Official Analytical Chemists Arlington VA 13th edn. 180 sect. 20.104. 1989 pt. 1 V O ~ . 11 ch. 3. pp. 189-235. 2 3 4 Authors must in their own interest check the lists of references against the original papers; second-hand references are a frequent source of error. References to conference abstracts which have not been published in the open literature are not acceptable. The number of references must be kept to a minimum. Nomenclature. Current internationally recognized (IUPAC) chemical nomenclature should be used. Common trivial names may be used but should first be defined in terms of IUPAC nomenclature. A listing of all relevant IUPAC nomenclature publications appears in the January issue.Symbols and units. The SI system of units as recommended by IUPAC should be followed. Their basis is the ‘Systkme Internationale #Unites’ (SI). A detailed treatment is given in the ‘Green Book’ Quantities Units and Symbols in Physical Chemistry (Blackwell Oxford 1988 edn.). The following will be the guidelines used (a) A metric system will always be used in preference to a non-metric one. (b) SI will be the standard usage. (c) The units used to record the definitive values of ‘critical data’ or quantities measured to a high degree of accuracy will be SI. These units are summarized in the Appendix. The current style of papers for JAAS includes the following (a) dimensions should preferably be given in metres (m) or in millimetres (b) temperatures should be expressed in K or “C (not OF); (c) wavelengths should be expressed in nanometres (nm) not mp; ( d ) frequency should be expressed in Hz (or kHz etc.) not in c/s or c.P.s.; rotational frequency can be denoted by use of s - l ; in mass spectrometry signal intensity should be expressed in counts s-’ and not in Hz; (mm); (e) radionuclide activity should be expressed in becquerels (Bq); ( f ) the micron (p) will not be used; will be 1 pm.When non-SI units are used they must be adequately explained unless their definition is obvious (e.g.,”C and A). The derivation of derived non-SI units should be indicated. Abbreviations. Abbreviational full stops are omitted after the common contrac- tions of metric units (eg. ml g pg mm) and other units represented by symbols.Abbreviations other than those of recognized units should be avoided in the text except after definition. Upper case letters without points should be used for abbreviations for techniques and associated terms subsequent to definition e.g. HPLC AAS XRF UV NMR SCE. The abbreviations Me Et Pr“ Bun Bu’ Bu‘ Bus Ph Ac Alk Ar and Hal can be used; others should be defined. Substituents should be indicated by R (one) or by R’ R2 R3 ... (more than one). Percentage concentrations of solutions should be stated in internationally recognized terms. Thus the symbols ‘m’ instead of ‘w’ for mass and ‘v’ for volume are to be used. The following show the manner of expressing these percentages together with an acceptable alternative given in parentheses YO m/m (g per 100 g); % m/v (g per 100ml); YO v/v.Further implications of the use of the term ‘mass’ are that ‘relative atomic mass’ of an element (A,) replaces atomic weight and ‘relative molecular mass’ of a substance (M,) replaces molecular weight. Concentrations of solutions of the common acids are often conveniently given as dilutions of the concentrated acids such as ‘dilute hydrochloric ( 1 + 4)’ which signifies 1 volume of the concentrated acid mixed with 4 volumes of water. This avoids the ambiguity of 1 4 which might represent either 1 +4 or 1 + 3. Dilutions of other solutions should be expressed in a similar manner. Molarity is generally expressed as a decimal fraction (e.g. 0.375 mol dm-3). Tables and diagrams. Table column headings should be brief.Tables consisting of only two columns can often be arranged horizontally. Tables must be supplied with titles and be so set out as to be understandable without reference to the text. Either tables or graphs may be used but not both for the same set of results unless important additional information is given by so doing. The information given by a straight-line calibration graph can usually be conveyed adequately as an equation or statement in the text. Column headings and graph axis labels should be in accord with SI conven- tions. Thus the expression of numerical values of a physical quantity should be dimensionless i.e. the quotient of the symbol for the physical quantity and the symbol for the unit used e.g. p/Pa or some mathematical function of a number e.g.In (p/Pa). Further examples are v/cm-’ I/cm mass of substance/g and flow rate/ml min-’. For units which are already dimensionless i.e. ratios such as ‘YO or ppm the type of ratio is indicated in parentheses e.g. e (‘YO) or e (ppm). The diagonal line (solidus) will riot be used to represent ‘per’. In accordance with the SI system units such as grams per millilitre are already expressed in the form g ml-’. It should be noted that the ‘combined’ unit g ml-l must not have any ‘intrusive’ numbers. To express concentration in grams per 100 millilitres the word ‘per’ will still be required Concentration/g per 100ml. It may be preferable for an author to express concentrations in grams per litre (g 1-’) rather than grams per 100 ml. Diagrams will be retraced and lettered if necessary in order to achieve uniform line thickness and lettering size and style.However all diagrams should be carefully and clearly drawn on good quality paper and should be carefully and clearly lettered. If possible chromatograms and spectra complicated flow charts circuit diagrams etc. should be supplied as artwork for direct reproduction in order to avoid time-consuming and expensive redrawing. The clearest copy should be without lettering.Three complete sets of illustrations should be provided two sets of which may be made by any convenient copying process for transmission to the referees. Photographs. Photographs can be submitted if they convey essential infor- mation that cannot be shown in any other way. They should be submitted as glossy or matt prints made to give the maximum detail.Colour photographs ,411 diagrams should be accompanied by a separately typed set of captions. be accepted Only when a photograph fails to show Some Wherever possible extensive identifying lettering should be placed in the caption rather than on lines on graphs etc. feature and can be either as prints Or transparencies. Appendix I The SI System of Units In the SI system there are seven base units- Symbol for Name Symbol Physical quantity quantity of unit for unit length mass time electric current thermodynamic temperature amount of substance luminous intensity 1 metre m kilogram t second I ampere T kelvin n mole I candela m kg S A K mol cd There are two supplementary dimensionless units for plane angle (radian rad) and solid angle (steradian sr).Some derived SI units that have special names are as follows- Name Symbol Physical of unit for unit Defnition of unit frequency force pressure stress energy work heat power electric charge electric potential electric capacitance electric resistance electric conductance magnetic flux magnetic flux density inductance hertz newton pascal joule watt coulomb volt farad ohm siemens weber tesla henry Examples of other derived SI units with no special names or symbols are- Physical quantity area volume density velocity angular velocity acceleration kinematic viscosity diffusion coefficient dynamic viscosity electric field strength magnetic field strength Hz N Pa J w C V F i2 S Wb T H SI unit Certain units will be allowed in conjunction with the SI system e.g.- square metre cubic metre kilogram per cubic metre metre per second radian per second metre per second squared square metre per second pascal second volt per metre ampere per metre Physical quantity Name of unit time plane angle volume magnetic flux density (magnetic induction) temperature t energy pressure mass minute degree Iitre gauss degree Celsius electronvolt bar unified atomic mass unit Symbol for unit min 0 1 G "C eV bar U Symbol for SI unit m2 m3 k m-3 m s-' rad s-' m s - ~ m2 s - l Pa s V m-' A m-' Defnition of unit 60s (~/180) rad m3=dm3 10-4 T tpC= T/K-273.16 1.6021 x lo-'' J lo5 Pa 1.660 54 x lop2' kgThe other common units of time (e.g.hour and day) will continue to be used in appropriate contexts. Decimal multiples and submultiples have the following names and symbols (for use as prefixes)- 10-3 10-9 1015 1024 10l2 lo1* 1 OZ1 milli micro nano pic0 femto atto zepto yocto 103 109 1015 1024 lo6 10l2 10lS 1 OZ1 kilo mega gigs tera peta exa zetta yotta k M G T P E Z Y Compound prefixes (e.g.mpm) should not be used; m = 1 nm. Appendix II Abbreviations Whenever suitable elements may be referred to by their chemical symbols and compounds by their formulae. The following abbreviations may be used without definition. ac AA AAS AE AES AF AFS AOAC APDC ASV CCP CMP CRM cw dc DCP DDDC DMF DNA EDL EDTA EDXRF EIE EPMA ETA ETAAS ETV EXAFS FAAS FAB FAES FAFS FI FPD FT FTMS GC GD GDL GDMS Ge( Li) HCL hf HG HPGe HPLC IAEA IBMK ICP ICP-MS IR IUPAC alternating current atomic absorption atomic absorption spectrometry atomic emission atomic emission spectrometry atomic fluorescence atomic fluorescence spectrometry Association of Official Analytical Chemists ammonium pyrrolidinedithiocarbamate (ammonium pyrrolidin-1-yl dithioformate) anodic-stripping voltammetry capacitively coupled plasma capacitively coupled microwave plasma certified reference material continuous wave direct current dc plasma diammonium diethyldithiocarbamate N N-dimethylformamide deoxyribonucleic acid electrodeless discharge lamp ethylenediaminetetraacetic acid energy dispersive X-ray fluorescence easily ionizable element electron probe microanalysis electrothermal atomization electrothermal atomic absorption spectrometry electrothermal vaporization extended X-ray absorption fine structure spectroscopy flame AAS fast atom bombardment flame AES flame AFS flow injection Flame photometric detector Fourier transform Fourier transform mass spectrometry gas chromatography glow discharge glow discharge lamp glow discharge mass spectrometry lithium-drifted germanium hollow cathode lamp high frequency hydride generation high-purity germanium high-performance liquid chromatography International Atomic Energy Agency isobutyl methyl ketone (4-methylpentan-2-one) inductively coupled plasma inductively coupled plasma mass spectrometry infrared International Union of Pure and Applied Chemistry LA LC LEAFS LEI LMMS LOD LTE MECA MIP MS NAA NaDDC NIES NIST NTA OES PIGE PIXE PMT PPm PTFE PVC QC rf REE(s) RIMS RM RSD SEC SEM SFC Si( Li) SIMAAC SIMS SR SRM SSMS STPF TCA TIMS TLC TOP0 TRIS TXRF uhf uv UV/VIS VDU vuv WDXRF XRF LOQ PPb SIB SIN laser ablation liquid chromatography laser-excited fluorescence spectrometry laser-enhanced ionization laser microprobe mass spectrometry limit of detection limit of quantification local thermal equilibrium molecular emission cavity analysis microwave-induced plasma mass spectrometry neutron activation analysis sodium diethyldithiocarbamate National Institute for Environemntal Studies National Institute of Standards and Technology nitrolotriacetic acid optical emission spectrometry particle-induced gamma-ray emission particle-induced X-ray emission photomultiplier tube parts per billion parts per million poly (tetrafluoroethylene) poly(viny1 chloride) quality control radiofrequency rare earth element(s) resonance ionization mass spectrometry reference material relative standard deviation signal-to-background ratio size-exclusion chromatography scanning electron microscopy supercritical fluid chromatography lithium-drifted silicon simultaneous multi-element analysis with a continuum source secondary ion mass spectrometry Signal to noise ratio synchrotron radiation Standard Reference Material spark source mass spectrometry stabilized temperature platform furnace trichloroacetic acid thermal ionization mass spectrometry thin-layer chromatography trioctylphosphine oxide 2-amino-2-( hydroxyrnethyl)propane-1,.3-diol total reflection X-ray fluorescence ultra-high-frequency ultraviolet ultraviolet-visible visual display unit vacuum ultraviolet wavelength dispersive X-ray fluorescence X-ray fluorescence The Royal Society of Chemistry Thomas Graham House Science Park Milton Road Cambridge UK CB44WF.Telephone +44 (0) 1223 420066; Fax +44 ( 0 ) 1223 420247; Internet JAAS@RSC.ORGINSTRUCTIONS FOR AUTHORS (1 996) APPENDIX IUPAC Publications on Nomenclature and Symbolism 1 .O Compilations 1.1 Nomenclature of Organic Chemistry a 550-page hardcover volume published in 1979 available from Pergamon Oxford. Section A Hydrocarbons Section B Fundamental heterocyclic systems Section C Characteristic groups containing carbon hy- drogen oxygen nitrogen halogen sulfur selenium and tellurium Section D Organic compounds containing elements not exclusively those referred to in the title of Section C Section E Stereochemistry Section F General principles for the naming of natural products and related compounds Section H Isotopically modified compounds 1.2 A Guide to IUPAC Nomenclature of Organic Compounds a 182-page softcover volume published in 1993 available from Blackwell Scientific Publications Oxford to be used in conjunction with item 1.1.1.3 Nomenclature of Inorganic Chemistry a 278-page hardcover volume published in 1990 available from Blackwell Scientific Publications Oxford. Chapter 1 General aims functions and methods Chapter 2 Grammar Chapter 3 Elements atoms and groups Chapter 4 Formulae Chapter 5 Names based on stoichiometry Chapter 6 Neutral molecular compounds Chapter 7 Names for ions substituent groups and radicals and salts Chapter 8 Oxoacids and derived anions Chapter 9 Co-ordination compounds Chapter 10 Boron hydrides and related compounds 1.4 Biochemical Nomenclature and Related Documents a 348-page softcover manual published in 1992 by Portland Press Ltd.for IUBMB and available from the publisher (59 Portland Place London WIN 3AJ UK). The contents are as follows Nomenclature of organic chemistry. Section E Stereo- chemistry (1974) Nomenclature of organic chemistry. Section F Natural products and related compounds (1 976) Is0 topically modified compounds Recommendations for the presentation of thermodynamic and related data in biology (1985) Citation of bibliographic references in biochemical journals (1971) Nomenclature and symbolism for amino acids and peptides (1983) Abbreviated nomenclature of synthetic polypeptides or polymerized amino acids (1 97 1) Abbreviations and symbols for the description of the conformation of polypeptide chains (1 969) Nomenclature of peptide hormones (1974) Nomenclature of glycoproteins glycopeptides and peptidoglycans (1985) Nomenclature of initiation elongation and termination factors for translation in eukaryotes (1988) Nomenclature of multiple forms of enzymes (1 976) Symbolism and terminology in enzyme kinetics (198 1) Nomenclature for multienzymes ( 1989) Abbreviations and symbols for nucleic acids poly- nucleotides and their constituents (1970) Abbreviations and symbols for the description of the conformations of polynucleotide chains (1 982) Nomenclature for incompletely specified bases in nucleic acid sequences (1 984) Carbohydrate nomenclature.Part I (1969) Nomenclature of cyclitols (1973) Numbering of atoms in myo-inositol(l988) Conformational nomenclature for five- and six-membered ring forms of monosaccharides and their derivatives (1980) Nomenclature of unsaturated monosaccharides (1 980) Nomenclature of branched-chain monosaccharides (1 980) Abbreviated terminology of oligosaccharide chains (1980) Polysaccharide nomenclature (1 980) Symbols for specifying the conformation of polysaccharide chains (1981) Nomenclature of lipids (1 976) Nomenclature of steroids (1 989) Nomenclature of quinones with isoprenoid side chains (1 973) Nomenclature of carotenoids (1 970) and amendments (1 974) Nomenclature of tocopherols and related compounds (1981) Nomenclature of vitamin D (1981) Nomenclature of retinoids (1 98 1) Prenol nomenclature (1986) Nomenclature of phosphorus-containing compounds of biochemical importance (1 976) Nomenclature and symbols for folic acids and related compounds (1986) Nomenclature for vitamins B-6 and related compounds (1 973) Nomenclature of corrinoids (1973) Nomenclature of tetrapyrroles (1 986) 1.5 Compendium of Analytical Nomenclature a 280-page hardcover volume published in 1987 available from Blackwell Scientific Publications Oxford.The contents are as follows Presentation of the Results of Chemical Analysis Solution Thermodynamics (activity coefficients equilibria P H) Recommendations for Terminology to be used with Precision Balances Recommendations for Nomenclature of Thermal Analysis Recommendations for Nomenclature of Titrimetric Analysis Electrochemical Analysis Analytical Separation Processes (precipitation liquid- liquid distribution zone melting and fractional crystallis- ation chromatography ion exchange) Spectrochemical Analysis (radiation sources general atomic emission spectroscopy flame spectroscopy X-ray emission spectroscopy molecular methods) Recommendations for Nomenclature of Mass Spec- trometry Recommendations for Nomenclature of Radiochemical Methods Surface Analysis (including photoelectron spectroscopy)INSTRUCTIONS FOR AUTHORS (1 996) 1.6 Compendium of Macromolecular Nomenclature a 172-page hardcover volume published in 199 I available from Blackwell Scientific Publications Oxford.The contents are as follows Basic Definitions of Terms Relating to Polymers Stereochemical Definitions and Notations Relating to Polymers Definitions of Terms Relating to Individual Macromolecules their Assemblies and Dilute Polymer Solutions Definitions of Terms Relating to Crystaline Polymers Nomenclature of Regular Single-strand Organic Polymers Nomenclature for Regular Single-strand and Quasi-single- strand Inorganic and Coordination Polymers Source-based Nomenclature for Copolymers A Classification of Linear Single-strand Polymers Use of Abbreviations for Names of Polymeric Substances 1.7 Compendium of Chemical Terminology IUPAC Recommendations a 456-page volume published in 1987 available in hardcover and softcover from Blackwell Scientific Publications Oxford.1.8 Quantities Units and Symbols in Physical Chemistry a 166-page softcover volume published in 1993 by Blackwell Scientific Publications Oxford.2.0 Documents not included in the compil- ations 2.1 Boron Compounds Nomenclature of inorganic boron compounds (Pure Appl. Chem. 1972,30,681). Nomenclature and terminology of graphite intercalation compounds (Pure Appl. Chem. 1994,66,1893). Recommended terminology for the description of carbon as a solid (Pure Appl. Chem. 1995,67,473). Glossary of class names of organic compounds and reactive intermediates based on structure (Pure Appl. Chem. 1995 67 1307). Nomenclature for cyclic organic compounds with contiguous formal double bonds (Pure Appl. Chem. 1988,60 1395). Names and symbols of transfermium elements (Pure Appl. Chem. 1994,66,2419). Enzyme Nomenclature (1992) published by Academic Press in hardcover and softcover editions.Revision of the extended Hantzsch-Widman system of nomenclature for heteromonocycles (Pure Appl. Chem. 1983 55,409). Names for hydrogen atoms ions and groups and for reactions involving them (Pure Appl. Chem. 1988,60 11 15). Nomenclature of inorganic chemistry. Part 11. 1. Isotopically modified compounds (Pure Appl. Chem. 1981,53,1887). Treatment of variable valence in organic nomenclature (Pure Appl. Chem. 1984,56 769). Nomenclature of hydrides of nitrogen and derived cations anions and ligands (Pure Appl. Chem. 1982,54,2545). Extension of Rules A-1.1 and A-2.5 concerning numerical Nomenclature of Elements and Compounds Carbon Class Names Delta Convention Elements Enzymes Heterocyclic Compounds Hydrogen Isotopically Modijied Compounds Lambda Convention Nitrogen Hydrides Numerical Terms terms used in organic chemical nomenclature (Pure Appl.Chem. 1986,58 1693). Nomenclature of polyanions (Pure Appl. Chem. 1987,59,1529). Nomenclature of regular double-strand (ladder and spiro) organic polymers (Pure Appl. Chem. 1993,65 156 I). Structure-based nomenclature for irregular single-strand organic polymers (Pure Appl. Chem. 1994,66,873). Graphic representations (chemical formulae) of macro- molecules (Pure Appl. Chem. 1994,66,2469). Basic classification and definitions of polymerization reactions (Pure Appl. Chem. 1994,66,2483). Revised nomenclature for radicals ions radical ions and related species (Pure Appl. Chem. 1993,65 1357). Chemical nomenclature and formulation of compositions of synthetic and natural zeolites (Pure Appl.Chem. 1979 51 1091). Polyanions Polymers Radicals and Ions Zeolites 2.2 Terminology Symbols and Units and Presentation of Results Glossary of terms used in physical organic chemistry (Pure Appl. Chem. 1994,66 1 OTJ7). Glossary of atmospheric chemistry tenns (Pure Appl. Chem. 1990,62,2167). Units for use in atmospheric chemistry (Pure Appl. Chem. 1995 67 1377). English-derived abbreviations for experimental techniques in surface science and chemical spectroscopy (Pure Appl. Chem. 1991,63 887). Analytical Recommendations for publication of papers on a new analytical method based on ion exchange or ion-exchange chromatography (Pure Appl. Chem. 1980,52,2555). Recommendations for presentation of data on compleximetric indicators 1.General (Pure Appl. Chem. 1979,51 1357). Recommendations for publishing manuscripts on ion-selective electrodes (Pure Appl. Chem. 198 1,53 1907). Recommendations on use of the term amplification reactions (Pure Appl. Chem. 1982,§4,2553). Recommendations for the usage of selective selectivity and related terms in analytical chemistry (Pure Appl. Chem. 1983 Nomenclature for automated and mec hanised analysis (Pure Appl. Chem. 1989,61 1657). Nomenclature for sampling in analytical chemistry (Pure Appl. Chem. 1990,62 1193). Nomenclature for chromatography (Pure Appl. Chem. 1993 65 819). Nomenclature of kinetic methods of analysis (Pure Appl. Chem. 1993,65,2291). Nomenclature for liquid-liquid distribution (solvent extraction) (Pure Appl. Chem.1993,65,2373). Nomenclature for supercritical fluid chromatography and extraction (Pure Appl. Chem. 1993,65,2397). Nomenclature and terminology for analytical pyrolysis (Pure Appl. Chem. 1993,65 2405). Nomenclature for the presentation of results of chemical analysis (Pure Appl. Chew. 1994,66 595). Recommendations for nomenclature in laboratory robotics and automation (Pure Appl. Chem. 1994,66,609). Nomenclature of interlaboratory analytical studies (Pure Appl. Chem. 1994,66 1903). Nomenclature of thermometric and enthalpimetric methods in chemical analysis (Pure Appl. Chem. 1994,66,2487). General 55 553).INSTRUCTIONS FOR AUTHORS (1 996) Classification and definition of analytical methods based on flowing media (Pure Appl. Chem. 1994,66,2493). Nomenclature for radioanalytical chemistry (Pure Appl.Chem. 1994,66,2513). Glossary of bioanalytical nomenclature-Part 1 General terminology body fluids enzymology immunology (Pure Appl. Chem. 1994,66,2587). Glossary for chemists of terms used in biotechnology (Pure Appl. Chem. 1992,64,143). Selection of terms symbols and units related to microbial processes (Pure Appl. Chem. 1992,64 1047). Physicochemical quantities and units in clinical chemistry with special emphasis on activities and activity coefficients (Pure Appl. Chem. 1984,56 567). Quantities and units in clinical chemistry (Pure Appl. Chem. 1979,51,2451). Quantities and units in clinical chemistry nebulizer and flame properties in flame emission and absorption spectrometry (Pure Appl. Chem. 1986,58 1737). List of quantities in clinical chemistry (Pure Appl.Chem. 1979 51,2481). Proposals for the description and measurement of carry-over effects in clinical chemistry (Pure Appl. Chem. 1991,63 301). Quantities and units for metabolic processes as a function of time (Pure Appl. Chem. 1992,64 1569). Quantities and units for electrophoresis in the clinical laboratory (Pure Appl. Chem. 1994,66,891). Quantities and units for centrifugation in the clinical laboratory (Pure Appl. Chem. 1994,66 897). Definitions terminology and symbols in colloid and surface chemistry. I (Pure Appl. Chem. 1972 31 577). XI Hetero- geneous catalysis (Pure Appl. Chem. 1976 46 71). Part 1.14 Light scattering (provisional) (Pure Appl. Chem. 1983,55,93 1). Reporting experimental pressure-area data with film balances (Pure Appl.Chem. 1985,57,621). Reporting physisorption data for gas/solid systems with special reference to the determination of surface area and porosity (Pure Appl. Chem. 1985,57,603). Reporting data on adsorption from solution at the solid/ solution interface (Pure Appl. Chem. 1986,58,967). Manual on catalyst characterization (Pure Appl. Chem. 1991 63 1227). Thin films including layers terminology in relation to their preparation and characterization (Pure Appl. Chem. 1994 66 1667). Nomenclature for transfer phenomena in electrolytic systems (Pure Appl. Chem. 1981,53 1827). Electrode reaction orders transfer coefficients and rate constants-amplification of definitions and recommendations for publication of parameters (Pure Appl. Chem. 1980,52,233).Classification and nomenclature of electroanalytical techniques (Pure Appl. Chem. 1976,45,81). Recommendations for sign conventions and plotting of electrochemical data (Pure Appl. Chem. 1976,45 13 1). Electrochemical nomenclature (Pure Appl. Chem. 1974,37,499). Recommendations on reporting electrode potentials in non- aqueous solvents (Pure Appl. Chem. 1984,56,461). Definition of pH scales standard reference values measurement ofpH and related terminology (Pure Appl. Chem. 1985,57,53 1). Interphases in systems of conducting phases (Pure Appl. Chem. 1986,58,437). The absolute electrode potential an explanatory note (Pure Appl. Chem. 1986,58,955). Electrochemical corrosion nomenclature (Pure Appl. Chem. 1989,61 19). Biotechnology Clinical Colloids and Sur$ace Chemistry Electrochemistry Terminology in semiconductor electrochemistry and photo- electrochemical energy conversion (Pure Appl.Chem. 199 1,63 569). Nomenclature symbols definitions and measurements for electrified interfaces in aqueous dispersions of solids (Pure Appl. Chem. 1991,63 895). Nomenclature symbols and definitions in electrochemical engineering (Pure Appl. Chem. 1993 65 1009). Terminology and conventions for microelectronic ion-selective field effect transistor devices in electrochemistry (Pure Appl. Chern. 1994,66 565). Impedances of electrochemical systems terminology nomen- clature and representation-Part 1 Cells with metal electrodes and liquid solutions (Pure Appl. Chem. 1994,66 1831). Terminology and notations for multistep electrochemical reaction mechanisms (Pure Appl.Chem. 1994,66,2445). Recommendations for nomenclature of ion-selective electrodes (Pure Appl Chem. 1994,66,2527). Symbolism and terminology in chemical kinetics (provisional) (Pure Appl. Chem. 1981,53,753). Kinetics of composite reactions in closed and open flow systems (Pure Appl. Chem. 1993,65,2641). Recommended standards for reporting photochemical data (Pure Appl. Chem. 1984,56,939). Glossary of terms used in photochemistry (Pure Appl. Chem. 1988,60 1055). . Expression of results in quantum chemistry (Pure Appl. Chem. 1978 50 75). React ions Nomenclature for organic chemical transformations (Pure Appl. Chem. 1989,61 725). System for symbolic representation of reaction mechanisms (Pure Appl. Chem. 1989,61,23). Detailed linear representation of reaction mechanisms (Pure Appl.Chem. 1989,61 57). Rheological Properties Selected definitions terminology and symbols for rheological properties (Pure Appl. Chem. 1979,51 1215). Recommendations for publication of papers on methods of molecular absorption spectrophotometry in solution (Pure Appl. Chem. 1978 50 237). Recommendations for the presentation of infrared absorption spectra in data collections. A Condensed phases (Pure Appl. Chem. 1978,50 231). Definition and symbolism of molecular force constants (Pure Appl. Chem. 1978,50 1709). Nomenclature and conventions for reporting Mossbauer spectroscopic data (Pure Appl. Chem. I976,45,2 1 1). Recommendations for the presentation of NMR data for publication in chemical journals. A Proton spectra (Pure Appl.Chem. 1972,29,625). B Spectra from nuclei other than protons (Pure Appl. Chem. 1976,45,217). Presentation of Raman spectra in data collections (Pure Appl. Chem. 1981,53 1879). Names symbols definitions and units of quantities in optical spectroscopy (Pure Appl. Chem. 1985,57 105). A descriptive classification of the electron spectroscopies (Pure Appl. Chem. 1987,59 1343). Presentation of molecular parameter values for IR and Raman intensity (Pure Appl. Chem. 1988,60 1385). Recommendations for EPR/ESR nomenclature and conven- tions for presenting experimental data in publications (Pure Appl. Chem. 1989,61,2195). Nomenclature symbols units and their usage in spectro- chemical analysis. VII. 'Molecular absorption spectroscopy UV Kinetics Photochemistry Quan tum Chemistry SpectroscopyINSTRUCTIONS FOR AUTHORS (1 996) and visible (Pure Appl. Chem. 1988 60 1449); VIII. Nomenclature system for X-ray spectroscopy (Pure Appl. Chem. 1991,63,735); X. Preparation of materials for analytical atomic spectroscopy (Pure Appl. Chem. 1988 60 1461); XII. Terms related to electrothermal atomization (Pure Appl. Chem. 1992 64 253); XIII. Terms related to chemical vapour generation (Pure Appl. Chem. 1992,64,261). Recommendations for nomenclature and symbolism for mass spectroscopy (Pure Appl. Chem. 1991,63 1541). Symbols for fine and hyperfine structure parameters (Pure Appl. Chem. 1994,66,571). Definitions of terms relating to phase transitions of the solid state (Pure Appl. Chem. 1994,66 577). A guide to procedures for the publication of thermodynamic data (Pure Appl. Chem. 1972,39 395). Solid State Thermodynamics Assignment and presentation of uncertainties of the numerical results of thermodynamic measurements (Pure Appl. Chem. 198 1,53 1805). Notation for states and processes; significance of the word ‘standard’ in chemical thermodynamics and remarks on commonly tabulated forms of thermodynamic functions (Pure Appl. Chem. 1982,54 1239). Standard quantities in thermodynamics fugacities activities and equilibrium constants for pure and mixed phases (Pure Appl. Chem. 1994,66 533). Recommendations for nomenclature and tables in biochemical thermodynamics (Pure Appl. Chem. 1994,66 1641). Glossary for chemists of terms used in toxicology (Pure Appl. Chem. 1993,65,2003). Toxic0 logy

ISSN:0267-9477    

DOI:10.1039/JA9961100075

出版商:RSC    

年代:1996

数据来源: RSC

摘要:

Paper Number ............................................................ RSC's use) THE ROYAL SOCIETY OF CHEMISTRY ("the RSC") COPYRIGHT LICENCE The Work (title and brief description of the paper or other contribution submitted) The Author (name and address) If the Author does not own the cop right in the Work state who the Owner is (givin name and address? and state why the Author does not own the copyrigat in the Work (eg the Author wrote the Work in the course of employment by the Owner) If the Author is the Owner then where used below "the Owner" means the Author. 1. 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ISSN:0267-9477    

DOI:10.1039/JA9961100083

出版商:RSC    

年代:1996

数据来源: RSC

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Royal Society of Chemistry Journals Department Guidelines for submission on disk These guidelines should be used in conjunction with the Instructions ,for Authors by authors wishing to submit a copy of their manuscript in electronic form. Successhl utilization of data on disk avoids duplication of effort and introduction of typographical error during typesetting. The following points should be noted during preparation of the manuscript to allow us to make the best use of the data provided. Hardcopy Disk Data Text Paragraphs Spaces Characters Tables Consistency - copies of the manuscript to be submitted in the usual way - Submission on disk should accompany the revised version of the manuscript such that the hardcopy to be edited and the data on the disk are identical - formatted for IBM (or compatible) PC or Macintosh - either 3.25 or 5.25" - clearly labelled (author name word processor type file format and file names) - accompanied on submission with a disk description form - text MS-Word Word for Windows Wordperfect and WordStar files accepted - double spaced - unjustified - ranged left - not hyphenated - no indent on first line - separated by carriage return - single spaces only after all punctuation including full point - note distinction between ell (1) and one (1) and upper case oh (0) and zero (0) - include at the end of the text file - use either the word processor's table editor or tabs for formatting but not a mixture of the two - check the manuscript carefully for consistency particularly in the representation of chemical formulae compound names and words with alternative spellings Use of the data supplied either in whole or in part cannot be guaranteed.Mathematical equations and tables in particular may be rekeyed by the typesetter. Page proofs should be checked in the usual way. The Royal Society of Chemistry holds personal information on a computerized database for publications administration purposes. We may from time to time wish to send you material relevant to your research interests to provide information about the Society's products or possibly to seek your advice on new products. If you do not wish to receive this or remain on our mailing list please contact the Journals Administration Officer. 04Royal Society of Chemistry Journals Department Authors’ Diskette Submission Details We welcome the submission of the text of your paper on a diskette in any of the formats listed below. If you wish to do this please complete this form with the required information and return it with your diskette to the editorial office. Please ensure that the diskette is clearly labelled with your name a short title of the paper and the hardware and software used. The data on the diskette must correspond exactly to the final hardcopy version supplied. Therefore please only supply disks with revised manuscripts. Paper ref. no. Journal Author name Paper title Disk details Hardware Software (text) PC Macintosh MS-Word version Word for Windows version Word Pe rfect version Wordstar version File names (text) Office use only Receipt date (disk) virus checked

ISSN:0267-9477    

DOI:10.1039/JA9961100084

出版商:RSC    

年代:1996

数据来源: RSC

摘要:

JOURNALS OF THE ROYAL SOCIETY OF CHEMISTRY Refereeing Procedure and Policy (1996) 1.0 Contributions to Dalton Perkin and Faraday Transactions J. Mater. Chem. The Analyst J. Anal. At. Spectrom. and J. Chem. Research 1.1 Introduction This document summarises the procedure used for assessing papers submitted to the four Transactions J. Mater. Chem. The Analyst J. Anal. At. Spectrom. and J. Chem. Research and provides guidelines for referees engaged in this assessment. 1.2 Subject Matter Papers are submitted to the various journals according to subject matter. If it is felt that a paper would be published more appropriately in an RSC journal other than the one suggested by the author the referee should inform the Editor. The topics covered by the various journals are as follows. Dalton Transactions (Inorganic Chemistry).All aspects of the chemistry of inorganic and organometallic compounds including bioinorganic chemistry and solid-state inorganic chemistry; the applications of physicochemical techniques to the study of their structures properties and reactions including kinetics and mechanism; new or improved experimental techniques and syntheses. Faraday Transactions (Physical Chemistry and Chemical Physics). Gas-phase kinetics and dynamics; molecular beam kinetics and spectroscopy photochemistry and photophysics; energy transfer and relaxation processes; laser-induced chemistry; spectroscopies of molecules molecular and gas- phase complexes; quantum chemistry and molecular structure; statistical mechanics of gaseous molecules and complexes; spectroscopies statistical mechanics and quantum theory of the condensed phase; computational chemistry and molecular dynamics; colloid and interface science surface science physisorption and chromatographic science chemisorption and heterogeneous catalysis zeolites and ion-exchange phenomena; electrode processes liquids and solutions; solid- state chemistry (microstructures and dynamics); reactions in condensed phases; physical chemistry of macromolecules and polymers; thermodynamics; biophysical chemistry and radia- tion chemistry. Perkin Transactions I (Organic Chemistry).All aspects of organic and bio-organic chemistry. These include synthetic organic chemistry of all types organometallic chemistry chemistry and biosynthesis of natural products the relationship between molecular structure and biological activity the chemistry of polymers and biological macromolecules and medicinal and agricultural chemistry where there is originality in the science.Perkin Transactions 2 (Physical Organic Chemistry). Physicochemical aspects of organic organometallic and bio- organic chemistry including kinetic mechanistic structural spectroscopic and theoretical studies. Such topics include structure-activity relationships and physical aspects of biological processes and of the study of polymers and biological macromolecules. Journal of Materials Chemistry. The chemistry of materials particularly those associated with advanced technology; modelling of materials; synthesis and structural characterisation; physicochemical aspects of fabrication; chemical structural electrical magnetic and optical properties; applications. The Analyst (Analytical Science).Theory and practice of all aspects of analytical chemistry fundamental and applied including inorganic and organic chemical physical and biological methods in applications areas such as environmental clinical geological industrial veterinary food etc. Journal of Analytical Atoinic Spectromeory. The development of fundamental theory practice and analytical application of atomic spectrometric techniques including ICP MS and XRF. Journal of Chemical Research. All areas of chemistry. The format of this journal (one- or two-page printed synopsis in Part S plus microform version of authors’ full text typescript in Part M) makes it particularly suitable for papers containing lengthy experimental sections or extensive data tabulations.1.3 Procedure Each manuscript is considered independently by two referees. The referees’ reports constitute recommendations to the appropriate Editorial Board which is empowered to take final action on manuscripts submitted. The Editor acting for the Editorial Board is responsible for all administrative and executive actions and is empowered to accept or reject papers. It is the Editor’s duty to see that as far as possible agreement is reached between authors and referees; although the referees may need to be consulted again concerning an author’s reply to comments further refereeing will be avoided as far as possible. 1.3.1 Adjudication of disagreements. If there is a notable discrepancy between the reports of the two referees or if the difference between authors and referees cannot be resolved readily a third referee may be appointed as adjudicator. In extreme cases differences may be reported to the appropriate Editorial Board for resolution.When a paper is recommended for rejection by referees the Editor will inform the authors and return the top copy of the manuscript. Authors have the right to appeal to the Editorial Board if they regard a decikion to reject as unfair. The Editor may refer to the Editorial Boards any papers which have been recommended for acceptance by the referees but about which the Editor is doubtful. 1.3.2 Anonymity. The anonymity of referees is strictly preserved and reports should be couched in terms which do not disclose the identity of the writer.A referee should never communicate directly with an author unless and until such action has been sanctioned by the Society through the Editor. 1.3.3 Conjidentiality. A referee should treat a paper received for assessment as confidential material. Information acquired by a referee from such a paper is not available for citation until the paper is published. 861.4 Policy The primary criterion for acceptance of a contribution for publication is that it should advance scientific knowledge significantly. Papers that do not contain new experimental results may be considered for publication only if they either reinterpret or summarise known facts or results in a manner presenting an advance in chemical knowledge.Papers in interdisciplinary areas are acceptable if the chemical content is considered satisfactory. Papers reporting results regarded as routine or trivial are not acceptable in the absence of other desirable attributes. Although short papers are acceptable the Society strongly discourages the fragmentation of a substantial body of work into a number of short publications; such fragmentation is likely to be grounds for rejection. The length of an article should be commensurate with its scientific content; however authors are allowed every latitude (consistent with reasonable brevity) in the form in which their work is presented. Figures and flow-charts can often save space as well as clarify complicated arguments and should not be excised unless they are unhelpful or really extrava- gant.The use of colour and/or half-tones is permitted in cases where genuine clarification results; referees are asked to advise on this. If a paper as a whole is judged suitable for the Journal minor criticisms should not be unduly emphasised. It is the responsibility of the Editor to ensure the use of reasonably brief phraseology and to assist the author to present his work in the most appropriate format. However referees should not hesitate to recommend rejection of papers which appear incurably badly composed. It should be clearly understood that referees’ reports are made in confidence to the Editor at whose discretion comments will be transmitted to the author. To assist the Editor referees are requested to indicate which comments are designed only for consideration as distinct from those which in the referee’s view require specific action or an adequate answer before the paper is accepted.Referees may ask for sight of supporting data not submitted for publication or for sight of a previous paper which has been submitted but not yet published. Such requests must be made to the Editor not directly to the author. 1.4.1 Authentication of new compounds. Referees are asked to assess as a whole the evidence in support of the homogeneity and structure of all new compounds. No hard and fast rules can be laid down to cover all types of compounds but the Society’s policy is that evidence for the unequivocal identification of new compounds should wherever possible include good elemental analytical data; for example an accurate mass measurement of a molecular ion does not provide evidence of purity of a compound and must be accompanied by independent evidence of homogeneity.Low-resolution mass spectrometry must be treated with even more reserve in the absence of firm evidence to distinguish between alternative molecular formulae. Where elemental analytical data are not available appropriate evidence which is convincing to an expert in the field may be acceptable. Spectroscopic information necessary to the assignment of structure should normally be given. Just how complete this information should be must depend upon the circumstances; the structure of a compound obtained from an unusual reaction or isolated from a natural source needs much stronger supporting evidence than one derived by a standard reaction from a precursor of undisputed structure.Referees are reminded of the need to be exacting in their standards but at the same time flexible in their admission of evidence. It remains the Society’s policy to REFEREEING PROCEDURE AND POLICY (1996) accept work only of high quality and to permit no lowering of standards. 1.5 Titles and Summaries Referees should comment on titles and summaries with the following points in mind. Titles of papers are used out of context by several organizations for current awareness purposes. To enable such systems to serve chemists adequately titles must be written around a sufficient number of scientific words carefully chosen to cover the important aspects of the paper. Summaries should preferably be self-contained so that they can be understood without reference to the main text.1.6 Speed of Refereeing The Editorial Boards are anxious to maintain and to reduce further if possible the publication times now being achieved. In this connection referees should submit their reports with the minimum of delay or return manuscripts immediately to the Editor if long delay seems inevitable. 1.7 Suggestions of Alternative Referees The Editor welcomes suggestions of alternative referees competent to deal with particular subject areas. Such suggestions are particularly helpful in cases where referees consider themselves ill-equipped (in terms of specialist knowledge) to deal with a specific paper and in highly specialized or new areas of research where only a limited number of experts may be available.If in such a case the alternative and the original referee work in the same institution the manuscript may be passed on directly after informing the Editor. 1.8 Short Papers and Letters ‘Short Papers’ are published in J. Chem. Research. They are intended for the description of essentially complete pieces of work which can be described in two printed pages or less. They are NOT preliminary communications nor in any way an alternative to Chemical Communications for which there are additional criteria of novelty and urgency. The quality of material contained in a short paper should be the same as that in a full paper. Investigations arising out of some larger project but not prosecuted to the same degree are particularly appropriate for this format.A short paper should not normally exceed in length about 8 pages of typescript including figures tables etc. It should comprise a one-sentence abstract and discussion but adequate experimental details are required. As a consequence of its length it appears in full in Part S with no microform version in Part M. ‘Letters’ published in Dalton Transactions are a medium for the expression of scientific opinions and views normally concerning material published in that journal; it is intended that contributions in this format should be published rapidly. The letters section is for scientific discussion and is not intended to compete with media for the publication of more general matters such as Chemistry in Britain. Only rarely should a Letter exceed one printed column in length (about 1-2 pages of typescript).Where a letter is polemical in nature and if it is accepted a reply will be solicited from other parties implicated for consideration for publication alongside the original letter. 1.9 Polemical Papers If the Editor considers a manuscript to be polemical in nature then the author of the paper being criticised will wherever possible be sent a copy of the manuscript.REFEREEING PROCEDURE AND POLICY (1996) 1.10 Relationship with Communications Journals In cases where a preliminary report of the work described has appeared (for example in Chemical Communications) referees should alert the editor to any excessive and unnecessary repetition of material; this can arise in connection with communications journals in which the restrictions on length and the reporting of experimental data are less severe than those of Chemical Communications.Furthermore the acceptability of the full paper must be judged on the basis of the significance of the additional information provided as well as on the criteria outlined in the foregoing sections. 2.0 Contributions to Chemical Communic- ations Chemical Communications is intended as a forum for preliminary accounts of original and significant work in any area of chemistry that is likely to prove of wide general appeal or exceptional specialist interest. Such preliminary reports should be followed up in most cases by full papers in other journals providing detailed accounts of the work. It is Society policy that only a fraction of research work warrants publication in Chemical Communications and strict refereeing standards should be applied.The benefit to the reader from the rapid publication of a particular piece of work before it appears as a full paper must be balanced against the desirability of avoiding duplicate publication. The needs of the reader not the author must be considered and priority in publication should not be allowed to determine acceptability. Acceptance should be recommended only if in the opinion of the referee the content of the paper is of such urgency or impact that rapid publication will be advantageous to the progress of chemical research. Communications should be brief and not exceed two pages in the printed form including Tables and illustrations - a maximum of 1500 words for a purely textual communication.Only in exceptional circumstances will a Communication be allowed to extend to four printed pages. Lengthy introductions and discussion extensive data and excessive experimental details and conjecture should not be included. Figures and Tables will only be published if they are essential to understanding the paper. Referees may .ask for sight of supporting data before reaching a decision. The refereeing procedure for Communications is the same as that for full papers except that rapidity of reporting is crucial in order to maintain rapid publication. 3.0 Communications submitted to Analytical Communications and J. Anal. At. Spectrom. Criteria for acceptance of communications submitted to Analytical Communications and J.Anal. At. Spectrom. are broadly similar to those for contributions to Chemical Communications except that they should be concerned specifically with analytical chemistry. Scientific importance (rather than urgency) is the main criterion for acceptance. A decision whether or not to publish rests with the Editor who will obtain advice from at least one referee. 4.0 Communications submitted to Perkin Dalton or Faraday Transactions or J. Mater. Chem. Criteria for acceptance of Communications submitted to Perkin Dalton or Faraday Transactions or J. Mater. Chem. are similar to those for contributions to Chemical Communications except that the work will he of more specialist interest. For Perkin and Dalton Communications inclusion of key experi- mental data is expected.Assessment is carried out by a small nucleus of referees consisting largely of members of the appropriate Editorial Boards. 5.0 Contributions to Mendeleev Communic- ations Mendeleev Communications published jointly by the Royal Society of Chemistry and the Russian Academy of Sciences is a sister publication to Chemical Communications containing preliminary reports of the same type in any area of chemistry. The majority of contributions are from Russian authors. Assessment involves two stages of refereeing. Manuscripts submitted to the Moscow Editorial Office are refereed initially by a Russian scientist. If found acceptable they are then reviewed by Western scientists chosen by the Royal Society of Chemistry. Manuscripts submitted to the UK Editorial Office undergo this two-stage refereeing process in reverse.6.0 X-Ray Crystallographic Work 6.1 All papers containing crystallographic determinations will be refereed by two referees one a structural chemist. If the editor considers it advisable the paper may also be sent to a specialist crystallographer for comment. Referees will not normally be expected to check values of structural parameters for publication (e.g. bond lengths and angles against atomic co- ordinates; this will be done after publication by the appropriate crystallographic data centre) but should still pay attention to the quality of the experimental crystallographic work. However their primary concern should be such new chemistry as is involved in the structure. 6.2 Papers will often contain the information in their titles that an X-ray structure determination has been carried out.However this is not obligatory especially if the X-ray determination forms only a minor part. Summaries should normally contain this information. 6.3 A structure referred to in a Communication will normally be fully refined. The Communication can then be considered to fulfil the archival function and the structure determination may not require further detailed refereeing when presented as part of a full paper. In the full paper the author’s purpose will then be served by a simple reference back to the original communication. However if the crystallography is discussed again at any length in the full paper the data should be re-presented to the referees in full and re-published if considered necessary.6.4 There may be other cases when an author wishes to publish a full .paper in which the result of a crystal structure determination is discussed but in which details or extensive discussion are considered unnecessary. The crystallographer may even be omitted as a co-author (for example when the determination is carried out by a commercial company). If the author is able to show the referees that this procedure is appropriate it will be allowed provided that it does not lead to unnecessary fragmentation. However the author must provide as supplementary information sufficient data relating to the crystal structure determination to allow a referee to make sure that the point made is correct and co-ordinates etc. will be deposited. The brief published description of the determination should be supplemented by appropriate reference to ‘unpub- lished work’.CONFIDENTIAL The Royal Society of Chemistry Thomas Graham House Science Park Milton Road Cambridge CB4 4WF Telephone +44 (0) 1223 420066 Fax +44 (0)1223 420247 E-Mail JAAS @RSC.ORG Dear Colleague Request for Referee’s Report - Journal of Analytical Atomic Spectrometry (JAAS) I would be grateful for your opinion on the acceptability of this manuscript for publication in JAAS.Some notes on publication policy are given below and fuller details are to be found in the Referee guidelines and Instructions to Authors. Your advice may conveniently be given as answers to the questions overleaf and comments on the separate sheet for the authors. If you are unable to send your report by the date indicated above please inform me at once.If you are unable to act as referee it will help if you can suggest someone in whose experience and ability to assess the manuscript for publication you have confidence. Should a suitable alternative referee be a colleague of yours would you please advise me and pass on the manuscript and this form. Fax or e-mail (a template is available on request) is recommended but the manuscript may be returned by normal mail (airmail if abroad). Receipt of your e-mail report will be acknowledged automatically. Yours sincerely Notes for Referees JAAS publishes papers on all aspects of atomic spectrometric analysis ICP-MS and XRF including fundamental studies novel instrument developments and practical analytical applications.Such papers may describe original work in a ’Full Paper’ Communication or Laboratory Note; or may present in review form a critical evaluation of the existing state of knowledge on a particular facet of analytical atomic spectrometry. The referees will not be identified in any way in any correspondence with the author. The Editor will be pleased to fulfil referees’ requests for further information about any paper on which they have reported and in cases where it would be helpful will supply in confidence the name of the co-referee. Data Protection Act If you prepare your report using any type of word processing system please note that you and the Society are jointly responsible for ensuring that the provisions of the Data Protection Act are complied with.In particular you should ensure that your report is prepared and stored securely and that it is not held for an excessive length of time. If you have any queries please contact the Publisher JournalsReferee’s Report to the Editor Please answer the following questions and add any comments necessary. Your detailed comments and recommendations for alterations directed to the author should by typed on the attached sheet without signature or reference. Please distinguish between comments intended to lead to correction of a definite error and those which the author should consider but may accept or reject at his or her discretion. 1. 2. 3. 4. 5 . 6. 7. 8. 9. 10. 11. 12. 13. Is there sufficient novelty and quality of scientific content? YESNO Are there any previous publications to which the author’s attention should be directed? (If so list them in your report to the author.) YESAVO Does the title adequately reflect the content? YESNO Are the objectives and salient features and quantitative information adequately stated in the abstract? YESNO Are the main analytes matrices techniques and/or concepts described by the keywords? YESAVO Does the Introduction adequately relate the current investigation to previous relevant studies? YESNO Are the Results clearly given with adequate statistics/validation methods? YESNO Is the Conclusion necessary and not duplicating statements made in discussion? YESAVO Is the length commensurate with the content? If too long please include in your report any recommendations for deleting text tables or illustrations.If too short please recommend additional worWdata that needs to be included or possible combination with another paper (fragmentation of work is strongly discouraged? YESNO Would the paper be more appropriate as a communication or interlaboratory note? Is your recommendation a) rejection b) acceptance with no alteration of scientific content c) acceptance subject to minor alterations d) acceptance subject to major alterations If d) do you wish to see the revised paper for final approval? For b) or c) or d) revised according to your wishes would you rate the paper overall as YESNO I I I 1 u YES/NO EXCELLENT / VERY GOOD / AVERAGE Date .................................. Signature of Referee .................... ....... .............. ................................................ ... . ... ....

ISSN:0267-9477    

DOI:10.1039/JA9961100086

出版商:RSC    

年代:1996

数据来源: RSC