摘要:

of the Analytical Division ofThe Chemical SocietyCONTENTS305 Society for Analytical ChemistryGold and SilverMedals305 Summaries of Papers305 'HPLC-Approaches by YoungerWorkers'309 'Plasma Emission Spectroscopy'315 Equipment News321 World Health Organization Report322 Obituary324 IUPAC Report324 Publications Received324 Courses325 Conferences and Meetings326 Analytical Division DiaryVolume 15 No 11 Pages 305-326 November 197PADSDZ 15(11)305-326(1978)ISSN 0306-1 396November 1978PROCEEDINGSOF THEANALYTICAL DIVISION OF THE CHEMICAL SOCIETYOfficers of the Analytical Divisionof The Chemical SocietyPresidentR. BelcherHon. SecretaryP. G, W. CobbSecretaryMiss P. E. HutchinsonHon. Treasurer Hon. Assistant SecretariesJ. K.Foreman D. I. Coomber. O.B.E.; D. C. M. Squirrel1Editor ProceedingsP. C. WestonProceedings is published by The Chemical Society.Editorial: The Director of Publications, The Chemical Society, Burlington House, London, W1 V OBN.Telephone 01 -734 9864. Telex 268001.Subscriptions (non-members): The Chemical Society, Distribution Centre, Blackhorse Road,Letchworth, Herts., SG6 1 HN.Non-members can only be supplied with Proceedings as part of a combined subscription with The Anelysfand Analytical Abstracts.@ The Chemical Society 1978ANALYTICAL DIVISIONTIEThe wider version of the tie bearing the SAC Coat of Arms is still available forsale to members of the CS Analytical Division. The tie, which carries a simp-lified version of the Coat of Arms woven in red, silver and gold as a singlemotif, is available in three different background colours-dark blue, dark greenand maroon. The tie is manufactured in a Crimplene - Terylene mixture.The price of the tie is L1.60, post free. The traditional, narrower versionof the tie is also still available (but in dark green only) at k1.10, post free.Orders, accompanied by the appropriate remittance, should be sent to TheSecretary, Analytical Division, The Chemical Society, Burlington House,Piccadilly, London, W 1V OBN.Please make cheques payable to The Chemical Society, and ensure thatthe background colour required on the tie is stated

ISSN:0306-1396    

DOI:10.1039/AD97815FX043

出版商:RSC    

年代:1978

数据来源: RSC

摘要:

November, 1978 CONFERENCES AND MEETINGS 325Ana lytica I Division Diary, continuedDecernbev, codinuedWednesday, 13th, 3 p.m.: LondonAnalytical Division : Silver Medal Meeting.“Interference Effects in Industrial InorganicAnalytical Chemistry,” by C. W. Fuller.“Recent Advances in Molecular Luminescence,4nalysis,” by J. N. Miller.Scientific Societies Lecture Theatre, 23 SavileRow, London, W. 1.Thursday, 14th, 2 p.m.: SalfordNovth West Region, jointly with the SalfordUniversity Chemical Society on “AnalyticalUses of Enzymatic Reactions. ”There will be several speakers and it is expec-ted that the discussion will include the useof enzymes for the assay of antibiotics andthe study of kinetic methods of enzymeanalysis. Further details may be obtainedfrom Mr.G. Davison, Kodak Ltd., ResearchDepartment, Acornfield Road, Kirkby,Merseyside, L33 7UF.The University, SalfordAnalytical Division DiaryNOVEMBERTuesday, 28th, 10 a.m.: LondonMicrochemical Methods and Special TechniquesGroups : Annual General Meetings andMeeting on “How to Attack Your Sample!Sample Preparation/Wet Digestion.”“Development and Application of High-pressure Dissolution in a Sealed Tube,” byD. Crossley.“Attempts at Higher Power, Lower Tempera-ture Ashing of Organic Materials,” by D. A.Pantony.“Some Experiences in the Use of PerchloricAcid for Wet Oxidation,” by R. C. Rooney.“Fusion-fluxes and Wider Aspects,” by G.Oliver,“Sample Preparation Techniques in Scanningand Transmission Electron Microscopy,’ ’ byS.Chapman.Scientific Societies Lecture Theatre, 23 SavileRow, London, W. 1.Thursday, 30th, 6.30 p.m.: LondonBiological Methods Group : Annual GeneralMeeting, followed by a Discussion Meetingintroduced by D. Jack.The Chemical Society, Burlington House,Piccadilly, London, W. 1.Thursday, 30th, 2 p.m.: LondonJoint Pharmaceutical Analysis Group :Meeting on “The Use of the Microscope.”Pharmaceutical Society of Great Britain,1 Lambeth High Street, London, S.E.l.DECEMBERFriday, lst, 4 p.m.: CardiffWestern Region : Annual General Meeting,preceded by a Joint Meeting with theSouth East Wales Section of the CS and theUWIST Chemical Society.“Thermometric Titrations, ” by ProfessorL. S. Bark.Chemistry Department, UWIST, Cardiff.Tuesday, 5th, 7 p.m.: EasthamNorth West Region, jointly with the Liverpooland District Section of CS/RIC and theCarlett Park Chemical Society.“Microprocessors in Chromatography-Pre-sent and Future,” by R.M. Petersen.Carlett Park College of Technology, Eastham,Wirral, Cheshire.Wednesday, 6th, 2 p.m. : SheffieldNorth East Region on “Water Pollution Moni-toring. ”“The Monitoring of Chlorinated OrganicMicropollutants in Drinking Water,” byM. Fielding.“The Application of d.c. Plasma Emission toTrade Effluent Analysis,” by C. J . Triner.“The Determination of Oil in IndustrialEffluents,” by F. J . Armson.“The Application of Continuous Monitoringto Water Quality Modelling,” by L. Ebdon,B. P. Mafferty and G. M. Doughty.Sheffield City Polytechnic, Pond Street Site,Sheffield, S1 1WE.Wednesday, 6th, 2.15 p.m.: LondonParticle Size A nalysis Group : Annual GeneralMeeting, followed by a meeting on “TheRelevance of Particle Size and Shape toPowder Consolidation.”“Fundamentals of Compaction and Consolida-tion,” by K.Ridgeway.“Tabletting of Pharmaceuticals,” by T.Jones.“Factors Controlling the Cold Compaction ofMetal Powders,” by P. James.Linnean Society Lecture Room, BurlingtonHouse, Piccadilly, London, W. 1 .Thursday, 7th, 2.10 p.m.: LondonAtomic Spectroscopy and Automatic MethodsGroups : Annual General Meetings, followedby a Joint Meeting on “Automation inAtomic Spectroscopy.”Geological Society Lecture Theatre, Burling-ton House, Piccadilly, London, W. 1.Friday, Sth, 2 p.m. : BirminghamElectroanalytical Group : Annual GeneralMeeting, followed by a Meeting andExhibition on “Electrochemical Sensorsand their Applications in Liquid Chromato-graphy. ”Holiday Inn, Birmingham.Friday, Sth, 2.30 p.m.: LondonChromatography and Electrophoresis and Educ-ation and Training Groups : Annual GeneralMeetings, followed by a Joint Meeting on“Forensic Science.”“Training for Forensic Science,” by P. G. W.Cobb.“Forensic Chromatography, ” by C. Candy.“Electrophoresis in Forensic Biology,” byChelsea College, University of London,Mrs. E. G. Emes.Manresa Road, London SW3 6LX.[continued inside back coverPrinted by Heffers Printers Ltd Cambridge Englan

ISSN:0306-1396    

DOI:10.1039/AD97815BX045

出版商:RSC    

年代:1978

数据来源: RSC

摘要:

Vol. 15 No. 11 November 1978 Proceedings of the Analytical Division of the Chemical Society HPLC-Approaches by Younger Workers The following are summaries of two of the papers presented at a meeting of the Western Region and the Chromatography and Electrophoresis Group held on May l l t h , 1978, at The Francis Hotel, Bath. Experiences in the Application of HPLC to the Analysis of P ha rmaceut ica I Compounds R.K. Harle P. R. Wood E. R. Squibb & Sons Ltd., Moreton, Merseyside, L46 1QW' Syntex Research Centre, Heriot- Walt University, Edinburgh The present popularity of high-performance liquid chromatography (HPLC) in the pharma- ceutical industry is partly due to its ability to analyse complex, involatile and labile compounds in mild conditions without derivatisation and with less sample clean-up than is required for gas - liquid and thin-layer chromatography.The instrumentation now available is complex, expensive and confusing to the inexperienced in its variety. It is often better to buy compon- ents from various manufacturers and assemble them, thus building a cheaper instrument with an appropriate specification and ready interchangeability of parts.The pump chosen depends on the use of the instrument, but generally the constant-flow pump is chosen for quantitative work. Constant-pressure types, such as gas-pressurised coil pumps, do not ensure flow reproducibility as series of unfiltered injections may cause column blocking. Valve application is chosen when one sample size from a relatively large volume of liquid is injected many times.It is highly reproducible and requires little operator training, whereas syringe injection needs a carefully standardised technique for the same reproducibility. A syringe can be used to inject virtually all of very small sample extracts and so is more useful in research functions. The fixed and variable wavelength ultraviolet detectors and the refractive index detector are commonly used.The variable wavelength detector enables compounds to be detected 305 Sample application may be by syringe injection or via a sample valve. Society for Analytical Chemistry Gold and Si lver M ed a Is On the recommendation of its Honours Com- mittee, the Council of the Analytical Division, at its meeting on September 27th, awarded Silver Medal to the fourteenth Society for Analytical Chem- istry Gold Medal to Mr.Stanley Greenfield Manager, Analytical Services, Detergents and Chemicals Group, Albright and Wilson Ltd., and the sixth Society for Analytical Chemistry Dr. James Noel Miller Senior Lecturer in Chemistry a t Loughborough University of Technology.306 HPLC-APPROACHES BY YOUNGER WORKERS Pvoc. Analyt.Div. Chem. SOC. with improved sensitivity and selectivity. The refractive index detector, while being almost a universal detector, has poor sensitivity unless its temperature is carefully controlled thermo- statically. HPLC columns of spherical bonded phase packing material are usually incorrectly assumed to be completely stable. Silica - carbon bonds can be hydrolysed in certain conditions and even the silica surface may be dissolved, undermining any attached bonded phase.We have found that stainless steel can be attacked by aqueous - organic solvents containing chloride ion when in continuous contact with the solvent. It is advisable to wash the column after use with a range of solvents in order to remove adsorbed materials and reduce erosion of the packing.Efficient column maintenance is essential for long life and reproducibility. The stages in the development of a drug into a marketable product are shown in Fig. 1. HPLC may be involved in each stage in the following types of assay: raw material and bulk drug assays establishing the purity of the components ; impurity and degradation product assays, to identify and quantify these compounds for correlation with toxicity and efficacy studies ; drug - excipient and excipient - excipient interaction investigations, showing ingredi- ents which can be safely combined; drug assays in different formulations, either batching assay for the control of manufacture, or stability assay, which separates and quantifies the drug in the presence of breakdown products formed in accelerated testing; and drug assay in bio- logical fluids in order to monitor the drug levels in clinical trials and in patients.Negative peaks render it difficult to use with electronic integrators. Basic Research Bulk Drug Pre-formulation . Candidate formulations 1 1 Pilot sta bi Ii t y tests 1 I 1 / l Characteri sat ion Drug - excipient and excipient - excipient interactions Pilot production Final formulation 1 1 Full stability tests .Market 4- Drug registration t Specifications Clinical trials Fig. 1. Development of a drug i n t o a product. The assay of drugs in various formulations can present unexpected problems in sample preparation. In the assay of nortriptyline in sugar-coated tablets1 the tablets were dissolved in water, followed by alkaline extraction of the nortriptyline base into cyclohexane and gas - liquid chromatographic assay.This procedure worked for tablet cores, but in the presence of the coating sugar gave low extraction efficiency. This problem was resolved by dissolving the coated tablets in aqueous internal standard solution and injecting the filtered solution on to a reversed-phase HPLC system, thus also reducing the clean-up stage.Cream formulations are often difficult to assay as they contain oils, waxes and emulsifiers, which interfere during HPLC. In the assay of triamcinolone acetonide in a topical cream formulation2 the steroid was separated from other cream excipients by adsorption on Florid, followed by elution from this column, addition of prednisolone internal standard and HPLC assay.This apparently cumbersome procedure gave good drug recoveries and reproducibility, was robust, easy to use and gave good HPLC column life. The drug Tiamulin can be used in drinking-water medication at low levels. This compound shows little ultraviolet absorbance and initial attempts to assay it in dilute solutions made use of an extraction - concentration technique from alkaline solution.This method worked for distilled-water solutions, but under field conditions, i.e., in drinking troughs, recoveries were low. Loop injection of 2 5 0 ~ 1 of aqueous solution directly on to the HPLC column gave pre-concentration of the drug near the column inlet, and subsequent elution by the organic eluting agent gave good chromatographic efficiency, accuracy and reproducibility. Thus, even apparently un- suitable compounds can be assayed by HPLC with the use of suitable techniques.The assay of drugs in blood is complicated by the low level of drug, small sample size and the presence of many interfering compounds. By careful choice of preliminary clean-up sample manipulation can be minimised, thus obtaining extracts that are directly applicable In veterinary work drugs may be administered in drinking water.November, 1978 HPLC-APPROACHES BY YOUNGER WORKERS 307 to HPLC.In the assay of Probenecid in serum,3 its extraction into ether from acidified serum, followed by removal of the ether and dissolution of the residue in the HPLC eluting agent, gave an extract in which interferences were negligible and which was directly injectable on to a reversed-phase HPLC column.References 1. 2. 3. Salmon, J . R., and Wood, P. R., Analyst, 1976, 101, 611. Gordon, G., and Wood, P. R., Analyst, 1976, 101, 876. Harle, R. K., and Cowen, T., Analyst, 1978, 103, 492. Pesticide Analysis-What Has H PLC to Offer? J. A. Hackwell and C. Self Shell Research Ltd., Shell Biosciences Laboratory, Sittingbourne Research Centre, Sittingbourne, Kent, ME9 SAG This paper is concerned with the quantitative analysis of pesticides, their technical materials and formulated products in research, development and quality control.Analytical methods are developed during the early research and development phase of a pesticide. As knowledge of the compound increases so the methods are improved, often being changed in the light of the route finally adopted for commercial production.By the time the compound is fully commercial, a sound reliable method or methods will exist for analysing the technical pesticide and its formulations. Such methods are developed at the Shell Biosciences Laboratory (SBL) and are subsequently used for providing quality assurance and technical assistance to manufacturing locations for both the technical material and the formulated products.The methods are also supplied to other laboratories, government and industrial, in the UK and abroad, and must therefore be reliable and capable of application with different manufacturers’ equipment in laboratories of varying scientific excellence. It is preferable, although not always possible, that one analytical method should be developed for the pesticide in both its technical material and formulated products.The method must, therefore, separate the active ingredient from the other components of the formulation (e.g., solvents, wetting agents, emulsifiers,) as well as from the impurities present in technical materials. For the last two decades, gas - liquid chromatography has provided a fast, specific and reli- able technique for the quantitative routine analysis of pesticides.The development and growth of high-performance liquid chromatography (HPLC) in the last 5-6 years has now provided a technique for use in instances where gas - liquid chromatography cannot readily be applied, for example, the analysis of thermally unstable, non-volatile or very polar compounds.HPLC can also be applied to virtually all compounds normally analysed by gas chromatography but the lack of a general detector, such as the flame-ionisation detector in gas chromatography, has to some extent limited its use. Equipment The equipment in use at SBL is simple but efficient, with the emphasis on reliability and stability.Solvent Delivery Systems Constant pressure pumps, such as the pressurised coil and the pneumatic amplifier, are used successfully for routine analysis. These devices are now being replaced by the newer genera- tion constant-flow, single- and dual-piston pumps. In some instances, however, it has been necessary to fit pressure restrictors and pulse damping coils between the pump and column in order to remove solvent pulsing.This is because these pumps operate at their maximum efficiency at pressures greater than 7.0 MPa (1 000 lb in-2), whereas the bonded phase packing materials and organic solvents in use at SBL generate much lower back pressures (e.g., 2.0 MPa, 300 lb in-2).308 HPLC-APPROACHES BY YOUNGER WORKERS Proc. Analyt. Div. Chem. SOC. Sample Introduction The injection valve is preferred for routine analysis as it is easy to use and not operator sensitive.Although Valco, Disc and Rheodyne injection valves are used at SBL, the inex- pensive Specac external loop injection valve, Model 30.100 (available from Analytical Access- ories Ltd., Orpington, Kent), has proved precise and reliable for most routine applications at relatively low pressures (less than 4.0 MPa, 600 lb in-2).The valve has a life in regular use of 6-12 months, but in our experience this is drastically reduced if the valve is operated at pressures over 7.0 MPa (1 000 lb in-2). Columns, Packings and Mobile Phases They are either packed at SBL by a high-pressure slurry-packing technique1 or obtained commercially from E. Merck Ltd.(Hibar range) or Whatman Ltd. (microparticulate silicas). Adsorption Chromatography on microparticulate silica and alumina was used extensively in our early development work. However, problems of irreversible column deterioration and differences in activity led to the increasing use of the more reproducible partition chromato- graphy on bonded-phase packing materials. The functional groups -NH2, -OH and -CN are available in bonded packing materials for normal-phase partition chromatography and hydro- carbon chains of c8 and c,, are available for reversed-phase chromatography.In the normal- phase technique, solvents such as hexane, dichloromethane, methanol, diethyl ether and 1,4- dioxan are used as mobile phases and methanol, acetonitrile and water are used for reversed phases.Most of the routine analysis at SBL is carried out by normal-phase partition chromato- graphy because partition chromatography gives stable, reproducible conditions for quantita- tive analysis. The compounds in use as pesticides tend to be soluble in organic rather than aqueous solvents and a relatively wide range of solvents and packing materials are available in order to achieve separations.Reversed-phase chromatography is used for some polar compounds, such as impurities in organophosphate insecticides. To date, gradient elution has not been necessary for any of the separations required in our routine analysis. The analytical columns used are normally 0.1 or 0.2 m by 4.5 mm i.d. Detectors Most pesticides analysed at SBL absorb in the ultraviolet range, so variable-wavelength ultraviolet detectors, such as the Cecil 212 and the Pye LC3, are used.Solution concentra- tions are typically 2-10 g 1-1 and therefore the detectors are operated on their least sensitive settings, on which they prove to be stable and reliable with a wide rectilinear range. Quantitation External calibration is the more convenient because of the difficulty of finding suitable internal calibrants for the wide range of compounds analysed.External calibration can be less precise than internal but in our experience, using a good reproducible injection valve, the two techniques are comparable in precision. For example, in the analysis of a herbicide with methyl benzoate as internal calibrant and using a Specac Model 30.100 injection valve, the coefficient of variation was *0.51% when using internal calibration as against &0.59% when using external calibra- tion (1 1 repeated injections).There is some controversy over whether peak height or peak area measurement is preferable for quantitative analysis. In an ideal system both peak height and peak area are proportional to concentration, and although both types of measurement are possible, the measurement of peak area can be carried out with much greater precision when using an elec- tronic integrator. However, our experience has shown that when carrying out an analysis under isocratic conditions peak height measurement often gives better precision than peak area.This effect is considered to be a function of the particular chromatographic system that is used.At SBL, both internal and external calibration are used routinely for HPLC. The same view has also been put forward by other workem2308 HPLC-APPROACHES BY YOUNGER WORKERS Proc. Analyt. Div. Chem. SOC. Sample Introduction The injection valve is preferred for routine analysis as it is easy to use and not operator sensitive. Although Valco, Disc and Rheodyne injection valves are used at SBL, the inex- pensive Specac external loop injection valve, Model 30.100 (available from Analytical Access- ories Ltd., Orpington, Kent), has proved precise and reliable for most routine applications at relatively low pressures (less than 4.0 MPa, 600 lb in-2).The valve has a life in regular use of 6-12 months, but in our experience this is drastically reduced if the valve is operated at pressures over 7.0 MPa (1 000 lb in-2). Columns, Packings and Mobile Phases They are either packed at SBL by a high-pressure slurry-packing technique1 or obtained commercially from E.Merck Ltd. (Hibar range) or Whatman Ltd. (microparticulate silicas). Adsorption Chromatography on microparticulate silica and alumina was used extensively in our early development work.However, problems of irreversible column deterioration and differences in activity led to the increasing use of the more reproducible partition chromato- graphy on bonded-phase packing materials. The functional groups -NH2, -OH and -CN are available in bonded packing materials for normal-phase partition chromatography and hydro- carbon chains of c8 and c,, are available for reversed-phase chromatography.In the normal- phase technique, solvents such as hexane, dichloromethane, methanol, diethyl ether and 1,4- dioxan are used as mobile phases and methanol, acetonitrile and water are used for reversed phases. Most of the routine analysis at SBL is carried out by normal-phase partition chromato- graphy because partition chromatography gives stable, reproducible conditions for quantita- tive analysis.The compounds in use as pesticides tend to be soluble in organic rather than aqueous solvents and a relatively wide range of solvents and packing materials are available in order to achieve separations. Reversed-phase chromatography is used for some polar compounds, such as impurities in organophosphate insecticides.To date, gradient elution has not been necessary for any of the separations required in our routine analysis. The analytical columns used are normally 0.1 or 0.2 m by 4.5 mm i.d. Detectors Most pesticides analysed at SBL absorb in the ultraviolet range, so variable-wavelength ultraviolet detectors, such as the Cecil 212 and the Pye LC3, are used.Solution concentra- tions are typically 2-10 g 1-1 and therefore the detectors are operated on their least sensitive settings, on which they prove to be stable and reliable with a wide rectilinear range. Quantitation External calibration is the more convenient because of the difficulty of finding suitable internal calibrants for the wide range of compounds analysed. External calibration can be less precise than internal but in our experience, using a good reproducible injection valve, the two techniques are comparable in precision. For example, in the analysis of a herbicide with methyl benzoate as internal calibrant and using a Specac Model 30.100 injection valve, the coefficient of variation was *0.51% when using internal calibration as against &0.59% when using external calibra- tion (1 1 repeated injections). There is some controversy over whether peak height or peak area measurement is preferable for quantitative analysis. In an ideal system both peak height and peak area are proportional to concentration, and although both types of measurement are possible, the measurement of peak area can be carried out with much greater precision when using an elec- tronic integrator. However, our experience has shown that when carrying out an analysis under isocratic conditions peak height measurement often gives better precision than peak area. This effect is considered to be a function of the particular chromatographic system that is used. At SBL, both internal and external calibration are used routinely for HPLC. The same view has also been put forward by other workem2

ISSN:0306-1396    

DOI:10.1039/AD9781500305

出版商:RSC    

年代:1978

数据来源: RSC

摘要:

November, 1978 PLASMA EMISSION SPECTROSCOPY 309 Plasma Emission Spectroscopy The following are summaries of two of the papers presented at a Meeting of the North West Region and the Atomic Spectroscopy Group held on May 17th, 1978, at The University, Salford. Line Selection and Correction for Spectral Background B. T. N. Newland Materials Quality Assurance Directorate, Royal Arsenal East, Woolwich, London, SE18 6TD The selection of emission lines in spectrochemical analysis is based on a number of criteria or factors, some essential, others desirable.Depending upon the instrumentation and specifica- tion of the material to be tested the relative emphasis placed upon individual factors may vary but, for a line of suitable intensity, a general purpose short list of requirements will be as follows.Essential: symmetrical line profile ; narrow half width ; not subject to self absorption. Desirable : freedom from spectral interference ; freedom from matrix and ionisation effects; emission intensity to vary linearly with analyte concentration. If an internal standard element line is used then, ideally, it should be homologous with the analyte line but as it is not always possible to select strictly homologous line pairs a more practical list of additional requirements is: if the internal standard element is to be added its concentration in the samples must be negligibly low and it should be very pure with respect to the elements sought ; the rates at which the internal standard and analyte elements volatilise should be similar; the internal standard and analyte lines should have similar excitation potentials; and the internal standard and analyte lines should not greatly differ in wavelength, in order to reduce the errors that might occur with photographic processing and measurement.Of lesser importance are the following requirements : the ionisation potentials of the internal standard and analyte elements should be similar; and the intensity ratio of the line pair should be insensitive to changes in matrix.The inductively coupled plasma (ICP) excitation source, compared with arc and spark excitation, possesses a number of advantages. The ICP system gives very little continuum emission, relative freedom from matrix and chemical interferences and self absorption is less pronounced.The use of a solution technique vitually eliminates problems such as metallurgi- cal history, inhomogeneity, sample form and surfacing and facilitates the preparation of calibra- tion standards. As with all atomic-emission procedures spectral interference can be a problem, Interference due to stray specular reflection within the instrument1 should be eliminated, or at least greatly reduced, by the manufacturer and the spectral interferences to be considered further are those due to continuum, molecular and atomic emission.At present there is little published data on the relative intensity of emission lines in ICP excitation. Experience at Woolwich indicates that differences exist between spectra excited310 PLASMA EMISSION SPECTROSCOPY Proc.AnaZyt. Div. Chem. SOC. in the ICP and those excited by arc or spark discharges. It is not always possible, therefore, t o predict the onset or degree of spectral interference on the basis of existing tables of arc and spark spectra. With photographic plate spectrographs all lines within the spectral range are available. However, the linear concentration range is limited by the photographic emulsion to about one and a half orders of magnitude, although this can be extended by the use of neutral density filters or a rotating stepped sector.Precision is often of the order of 5y0, although 2y0 (and better) can be obtained., With simultaneous direct reading spectrometers the choice of lines is limited by the physical dimensions of the slits and photomultipliers and the dispersive power of the instrument.A linear concentration range of four to five orders of magnitude can be achieved3v4 and precisions of the order of 1% have been obtained. Correction for continuum emission and the apparent enhancement of background occurring in the presence of some elements, which is consistent over a relatively wide waveband, can be effected by monitoring and subtracting the signal contribution of the background adjacent to the selected emission line or at a pre-selected fixed wavelength. Molecular band emission can produce a rapidly changing background necessitating measure- ment at higher and lower wavelengths adjacent to the element line. Similar correction may be needed where the analyte line appears as a “shoulder” not fully resolved from a strong matrix line.Direct atomic line interference can be measured from the spectrum of the inter- ferent only, at a concentration equivalent to that occurring in the sample. Alternatively, correction can be effected by monitoring another line of the interferent and applying an empirically determined factor. Other workers have investigated the application of background correction in simultaneous direct reading spectrometer^.^,^ The measurement of background adjacent to the fixed analytical wavelength can be made by offsetting the spectrum’ or scanning a small, discrete, waveband, for example by means of a refractor plate.819 Alternatively, a scanning mono- chromatorlo can be used to monitor intermediate wavelengths as required.Spectral interference is readily observable on photographic plates but, if a significant interference is present, each measured image density must be converted to relative intensity before subtracting the contribution of the background.I t is necessary to calibrate the photo- graphic emulsion, by means of a rotating stepped sector for example, in order to obtain a density - relative intensity graph. In addition, with spectral line overlap it will be necessary to prepare spectra of the internal standard and interferent, or interferent only, at a con- centration equivalent to that occurring in the sample.Subsequent corrections based on the empirically established intensity relationship between alternative lines of the interferent can be applied. With ICP excitation the complex matrix effects such as occur in arc and spark excitation are virtually eliminated and correction for spectral interference becomes a simple mathematical exercise. Correction for the low continuum emission is rarely necessary unless the analyte signal is small.Some molecular band emission is usually present, e.g., OH- or, with organic materials, the C, Swan bands, but these emitters cause serious interference with only a few elements, e g ., Bi 306.77 nm and OH- 306.72 nm. When no alternative line is available and excessive spectral line overlap occurs the solution technique readily accommodates separation procedures. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. References Fassel, V. A., Haas, W. J., Jr., Katzenberger, J. M., Kniseley, R. N., Larson, G.F., and Winge, R. K., Newland, B. T. N., and Mostyn, R. A., I C P I n f . Newsl., 1976, 2, 135. Butler, C. C., Kniseley, R. N., and Fassel, V. A., Analyt. Chem., 1975, 47, 825. Boumans, P. W. J. M., I C P I n f . Newsl., 1977, 3, 71. Ward, A. F., Sobel, H. R., and Crawford, R. L., I C P I n f . Newsl., 1977, 3, 90. Dahlquist, R. L., and Knoll, J. W., Appl. Spectrosc., 1978, 32, 1.Wohlers, C. C., ICP I n f . Newsl., 1976, 2, 196. Snelleman, W., Rains, T. C., Yee, K. W., Cook, H. D., and Menis, O., Analyt. Chem., 1970, 42, 394. Koirtyohann, S. R., Glass, E. D., Yates, D. A., Hindenberger, F. J., and Lichte, F. E., Analyt. Chem., Ward, A. F., I C P In.. Newsl., 1977, 3, 51. I C P Inf. Newsl., 1976, 2, 195. 1977, 49, 1621.November, 1978 PLASMA EMISSION SPECTROSCOPY 31 1 Applications and Problems of the Inductively Coupled Plasma in the Chemical Industry E.J. Newman and R. N. Farrow BDH Chemicals Ltd., Broom Road, Poole, Dorset, BH12 4NN Our interest in the inductively coupled plasma (ICP) at BDH is primarily in the determination of trace impurities in the chemicals that we sell and in our raw materials. Samples are normally tested to meet a specification, ie., the metals to be determined and their maximum levels are known.Our initial work has been directed towards the analysis of acids, solvents and other samples where an ashing or evaporation procedure can be used to remove the matrix. The application of the ICP to salts in solution presents special problems which will be mentioned later . The limits range typically from 0.001 pg g-l for lead to 0.5 pg 8-l for calcium, strontium, magnesium and sodium.This range illustrates the annoying fact that there is often an inverse relationship between the amount to be determined and the sensitivity; the ICP detection limit for lead is worse than those for calcium, strontium and magnesium. We installed an ICP instrument about 9 months ago and it has been in routine use for the analysis of solvents and acids for about 3 months.The RF generator is a Radyne R50, giving a maximum power output of 5 kW. The plasma torch is of the large type described by Greenfield et aZ.l and we use nitrogen cooling. Sample intake is via a peristaltic pump and the nebuliser is of the concentric type. The spectrometer is a Rank - Hilger ElOOO direct reading instrument.Counts of integrated intensity for each of the selected channels are presented on the typewriter at the end of the exposure time. As the wavelength range of the ElOOO does not cover the important potassium line at 766 nm we fitted a separate, adjustable mono- chromator viewing the plasma from the opposite side. Originally we used a Beckman DU, which is a small prism instrument.Recently, we have replaced this with the 0.8-m Optica grating instrument. The instru- ment is set up with 44 channels. For some very common metals (calcium, copper, iron, magnesium, manganese, nickel, lead and zinc) two channels are provided in order to allow for spectral interference, which might occur in some instances. One channel is used for the Optica monochromator. The instrumental variables that affect sensitivity are: power applied to the plasma; viewing height; and the gas flows for the injector, plasma and coolant.The effect of plasma gas flow is relatively small and we fixed this at 5 1 min-l. The effect of coolant flow was not investig- ated. The effect of power depends primarily on the nature of the line concerned.In general, atom lines have best sensitivity at low powers, while ion lines are favoured by high power. Fig. 1 shows the effect of power on the atom and ion lines for calcium and manganese. The intensities of the various lines have been adjusted to read 3 000 for the most sensitive power setting; the graphs are intended to indicate changes in intensity with power and not the relative sensitivity of different lines.The power setting is an arbitrary scale taken from the Radyne power control. The range covered here corresponds approximately to 1.0-3.4 kW in the plasma. This figure shows the effect of power on intensity but it should be noted that the background rises with increase in power. If the effect of power on line to background ratios is considered then the difference between the manganese lines becomes clearer.The line to background ratio is largest at high powers for the ion line and at low powers for the atom line. The behaviour of the ion line is rather different from that which has been reported by Boumans and DeBoer2 for the smaller, argon-cooled torch. In the latter instance both manganese lines show the best signal to background ratios at lower powers. Because atom lines are favoured by low power we investigated the effect of ionisation buffers, particularly the effect of caesium chloride at concentrations up to 80% m/V on the manganese I and I1 lines.We found that the caesium chloride concentration has a marked effect on ionisation, at least under low power conditions (power setting 120 used).The intensity of the atom line increased up to a 40% m/V concentration of caesium chloride. The ion line showed a corresponding fall in intensity with increasing caesium chloride concentration. Caesium chloride also increased the intensity of the lead I line at 283.3 nm. At this stage we The specification of an Aristar high purity acid may list up to 20 metals. This is, of course, useful for metals other than potassium.The remaining three factors have a marked effect on sensitivity.312 PLASMA EMISSION SPECTROSCOPY Proc. Analyt. Div. Chem. SOC. particularly concentrated our efforts on optimising the conditions for lead. From a consider- ation of published detection limits we were aware that lead might be the most difficult metal to determine because our specification limits for it are almost always lower than those for most other metals.We investigated the effect of caesium chloride concentration on both net intensity and line to background ratio. We found that the maxima of the two graphs occur at different con- centrations of caesium chloride so that we had to decide whether to optimise for intensity or line to background ratio.We should also, of course, consider the effect of various factors on precision. This does not seem to be important, however, as our coefficients of variation seem to remain at around 1% under any conditions we have used provided that the signal is at least 100 counts. We would like to optimise for maximum line to background ratio but this can lead to rather small signals in some instances.In practice, we tend to use conditions that compromise between maximum line to background ratio and maximum intensity. Having decided to use an ionisation buffer we chose to use lithium chloride (or more recently, lithium nitrate) as this tends to be purer than caesium chloride. The purity of the ionisation buffer is important because of the high concentrations involved.The effect of lithium chloride is shown in Fig. 2. We decided to use a concentration of 5% m/V. Power setting 0 10 20 Concentration of lithium chloride monohydrate, % niiV Fig. 1. Effect of power on Fig. 2. Eflect of lithium calcium and manganese lines. chloride on lead. We then looked at the effects of different variables on the determination of lead in the presence of 5% m/V lithium chloride solution.Both line to background ratio and net intensity are favoured by low power settings on the Radyne unit. We selected a setting of 120, which gives a compromise between optimum line to background ratio and intensity. Injector flow-rate has a marked effect with both line to background ratio and intensity, having maxima at 1.6 1 min-l. The effect of viewing height over the range 10-30 mm has a relatively small effect.Having decided on the conditions that we would like to use for lead we looked at the other metals to see whether they could be determined adequately under the same conditions. Thus our compromise conditions are very much biased towards one metal and do not attempt to balance the sensitivities of all of the metals.The detection limits were determined for the commoner metals in solutions containing 10% m/V lithium nitrate, water and 5% V/V nitric acid (Table I). These detection limits have proved adequate for our purpose, although we should like to see higher sensitivity, particularly for lead and zinc. The amounts of metals added correspond to the amounts expected from a typical Aristar specification, assuming that the sample has been concentrated one hundred fold.The wide range of linear- We use a height of 20 mm. Recovery tests of metals from lithium nitrate solution were then made.iNovember, 1978 PLASMA EMISSION SPECTROSCOPY TABLE I DETECTION LIMITS UNDER COMPROMISE CONDITIONS 313 Conditions used : power setting, 120 (approximately equivalent to 2.4 kW applied to the work coil) ; plasma flow, 5 1 min-l; injector flow, 1.6 1 min-l of argon; coolant flow, 20 1 min-l of nitrogen ; viewing height, 20 mm; and matrix, 10% yn/ V LiNO,H,O and 5% V / L' HNO,.Metal Ag A1 B Ba Ca Cd CO Cr c u Fe Wavelength/ Detection limit*/ nm pg ml-l 328.1 396.1 249.8 455.4 393.4 228.8 345.4 425.4 324.8 372.0 0.006 0.006 0.01 0.002 0.004 0.04 0.009 0.004 0.001 0.01 Metal Mn Mo Na Ni Pb Si Sn Sr Zn Mg Wavelength/ Detection limit*/ nm pg ml-1 279.6 403.1 379.8 589.0 361.9 283.3 251.6 303.4 460.7 213.9 0.003 0.005 0.004 0.03 0.009 0.04 0.02 0.04 0.01 0.15 * Detection limit = concentration equivalent to 2 x standard deviation of the blank ity of the ICP means that it is not necessary to use more than one standard.We use the same concentration of standard (10 pg ml-l) for all metals. Duplicate exposures were made on blank, sample and standard and the results were calculated on a programmable calculator.The recoveries were satisfactory and the coefficients of variation were mostly around 1%. The lead concentration is only about three times the detection limit and this is reflected in the poor standard deviation (17%).A comparison of results obtained by use of ICP and atomic-absorption spectrophotometry for a sample of hydrochloric acid is shown in Table 11. The agreement between the two techniques is satisfactory. TABLE I1 COMPARISON OF RESULTS OBTAINED BY ICP AND AAS FOR SAMPLE OF HYDROCHLORIC ACID Results found by- Metal A1 Ca Cd co c u Fe K Mn Na Ni Pb Sr Zn Mg ICP/PLg 8-l 0.13 0.17 0.003 7 0.000 3 0.003 3 0.22 0.04 0.066 0.004 0.37 0.004 4 0.003 0.001 5 0.054 1 **S/PLg 8-l 0.14 0.17 0.004 7 0.000 4 0.004 0.21 0.043 0.072 0.004 0.36 0.005 0.003 5 0.001 4 0.058 Recently we have started investigating the determination of impurities in salts.We showed above that the presence of alkali metal salts can have a marked effect on sensitivity. This effect would probably be reduced at a higher power but we still need to make use of the enhancing effect obtained at low powers because of the low levels of lead that we have to determine.The effect of the sample on sensitivity can be overcome by using a standard additions technique. If we make exposures using water and then, say, 10% m/V sodium nitrate solution, we tend to find an increase in intensity with the sodium nitrate that cannot be related to known impurities in the sodium nitrate.This is a result of stray light in the spectrometer and possibly also to continuum emission from the sodium. This effect is well known in flame emission spectro- scopy, in which correction is usually made by scanning the background adjacent to the line. A further problem is the effect of the sample on background.314 PLASMA EMISSION SPECTROSCOPY Proc.Analyt. Div. Chew. SOC. Direct reading spectrometers are, of course, not designed to scan emission lines. The El000 direct reading instrument has micrometer controls on the two entrance slits. These controls are intended for profiling lines when the instrument is set up but they can be used in order to obtain wavelength profiles of lines in the plasma to determine the background adjacent to the line.This is a tedious procedure and is not suitable for routine determinations, but it can be useful at the investigational stage. Fig. 3 shows the wavelength profiles obtained at the 324.8 nm copper line for 10% m/V sodium nitrate, 10% m/V sodium nitrate plus 0.2 pg ml-l copper solution and distilled water. The horizontal axis should be read as an arbitrary wavelength scale.The increase in back- ground on spraying the sodium nitrate is approximately constant over this wavelength region. The amount of copper added corresponds to the amount that we would normally wish to determine, so that we can say that the error which would arise from using distilled water as the blank would be less than 10% in this instance.If we now consider a metal that is less sensitive we find that the position is less satisfactory. Fig. 4 shows the wavelength profile for lead at 283.3 nm in 10% m/V sodium nitrate solution. This lead line is much less sensitive than the copper line. This implies that a higher EHT must be used on the photomultiplier, which results in a wider divergence between readings for the sample and water.The amount of lead added is 10 times the amount that we need to determine so that we can see that the error which would arise from using water as the blank could be as high as 200%. We can also see that any system that determines a background correction by reading the background adjacent to the line would not be valid in this instance.-200 0 +200 Slit position, arbitrary scale Fig. 3. Wavelength profile of copper in sodium nitrate solution. A, Sodium nitrate 10% m/V + 0.2 pg ml-l copper; B, sodium nitrate 10% m / V ; and C, water. 0 0 +200 Slit position, arbitrary scale Fig. 4. Wavelength profile of lead in sodium nitrate solution. A, Sodium nitrate 10% m/I’ + 2 pg ml-l lead: B, sodium nitrate 10% m / V ; and C, water.We next looked at this shift in background for a range of sodium salts to see whether the effect was dependent only on the amount of sodium in solution. The solutions of the various salts were made equimolar in sodium. Standards were also prepared in each salt solution in order to obtain a slope (m) for each calibration line. The blank readings for each salt were corrected for the effect of any impurity known to be present.Table I11 shows the results for magnesium and lead in the range of sodium salts. The magnesium line is ionic and has high sensitivity, while the lead atom line has relatively poor sensitivity. The slopes (m) of the calibration graphs for the metals are reasonably constant over the whole range of salts. Com- parison with the slope for water again shows the enhancement of lead by the alkali metal.In contrast the magnesium ion line is partly suppressed. The error column gives the error that would arise in the determination of the AnalaR limit amount if the mean blank and slope were used rather than the true values for each salt. With magnesium the errors are negligible butNovember, 1978 EQUIPMENT NEWS 315 this is not so for lead.These results are a reflection of the intensities of the two lines and also the concentration of each metal determined. The error is inversely proportional to con- centration, so that if we are determining 20 p.p.m. of lead rather than 2 p.p.m. then the errors drop to a more acceptable level. TABLE I11 EFFECT OF SODIUM SALTS ON BLANK AND SENSITIVITY Magnesium Lead 7-m r-, Slope Error* for Slope Error* for Sample Molarity (m) 20 p.p.m., yo (m) 2 p.p.m., % KaCl 1 961 KaH,PO,.ZH,O 1 94 1 NaNO, 1 1 000 Na,SO, 0 .5 974 Na, citrate 0.33 939 Na acetate 1 925 Na,HPO, 0.5 989 1 101 0 1 95 32 1 110 - 3 1 110 - 66 1 108 - 50 2.3 110 114 1 103 - 44 - 30 JVster - 1294 - * Error which would arise from using mean slope and mean blank.-4nother factor that affects the analysis of salts is the concentration of the sample which can be tolerated by the nebuliser - plasnia system. We showed earlier that 80% m/V solutions of caesium chloride could be used without any blockage occurring, but this is a very soluble salt (solubility 162% m/V). Less soluble salts can cause a blockage by crystallising in the injector tube or in the nebuliser. The problem of sample crystallisation in the injector tube can be reduced by using a larger bore tube. We found that this change also improved the performance for lead. We normally use a 2 mm bore tube with an injector flowof 1.6 1 min-l. By using a 4mm bore at a higher injector flow we can obtain a 33% increase in intensity. There is also a slight improvement in the detection limit. A similar experiment on zinc again showed an increase in intensity on going to a 4-mm injector tube but in this instance an increase in injector flow is not an advantage. The detection limit is substantially improved by using the larger bore. Further work on the use of large bore injector tubes is planned but the preliminary results indicate that there is a tendency for the performance of atom lines to be improved while with ion lines there is a loss of sensitivity. Our instrument has only been fully operational for about 7 months and more investigational work is planned. At present the instrument is handling the routine analysis of all acids and solvents. We hope shortly to start analysing salts for trace metal contents. References 1. 2. Greenfield, S., Jones, I. Ll.,McGeachin,H. McD., and Smith, P. B., Analytica Chirn. Acta, 1975, 74, 225. Boumans, P. W. J. M., and DeBoer, F. J., Spectrochirn. Acta., 1977, 32B, 365.

ISSN:0306-1396    

DOI:10.1039/AD9781500309

出版商:RSC    

年代:1978

数据来源: RSC

摘要:

November, 1978 Equipment News EQUIPMENT NEWS Laser Sources Two new laser products, the Spectrolas El and the LA04 nitrogen laser are announced. The Syectrolas El is a pulsed dye laser, pumped by a nitrogen laser with short cavity and a high efficiency holographic grating to give a high conversion efficiency (15%) and high resolution (0.1 nm). The dye cell is interchangeable with or without dye circulation.The LA04 nitrogen laser is a pulsed laser with 315 high performance and reliability, operating at 40-80 Torr to give an output wavelength of 337.1 nm, with a pulse energy of 4-6 m J at 6-ns duration. EDT Research, 14 Trading Estate Road, Park Royal, London, NWlO 7LU. The peak power is 60-1 000 kW. High - voltage Image - intensifier Supply The Brandenburg Model 82 1 high-voltage power supply is designed for use with image-intensifier316 EQUIPMENT NEWS Proc.Analyt. Div. CJzem. SOC. tubes, having five outputs including a dual- mode grid supply. The Model 821 produces outputs ranging up to 30 kV at 2 PA from a d.c. supply of 38 V as follows: grid 1, 90-434 V at 5pA; grid 2, 540-1655V a t l p A ; grid 3, 2.5 or 3.8 kV a t 1 PA; grid 4, 2.5-3 kV a t 10 PA; and anode, 30 kV a t 2 PA.Input voltage can vary by +lo% or -15% with a maximum ripple current of 10% (peak-to-peak). The Model 821 is capable of withstanding short-term overloads, flashovers and output short-circuit conditions. Maximum output voltage dV/dt is 5 kV ms-l. Brandenburg Ltd., High Voltage Engineering, 939 London Road, Thornton Heath, Surrey, CR4 6JE.Polarising Microscopes A polarising version of the M 17 microscope, equipped for transmitted illumination, is announced. Viclters Instruments, Vickers House, Mill- bank Tower, London, SWlP 4RA. Optoacoustic Spectrometer A commercial optoacoustic spectrometer is now available. The instrument works by shining a beam of light on to the specimen to be examined, which is sealed in a tiny transparent cell. Light is absorbed to a different extent depending on the nature of the specimen. This causes the specimen to heat up and the air in the sealed cell to expand. If the beam of light is then inter- rupted in a regular fashion by a rotating shutter, the process of successive heating and cooling will set up a series of pressure waves in the cell.These waves can be recorded by using a sensitive microphone.Wavelengths from ultraviolet to infrared can be focused on to the specimen in turn, and in this way one can establish those wavelengths which the specimen absorbs. Following this operation, the specimen's chemi- cal composition can be determined. EDT Research Ltd., 14 Trading Estate Road, Park Royal, London, NWlO 7LU. Light Fastness Tester Accessories A new accessory is the AB water-cooled cell, which will accept very thick samples, such as carpets, which may be 11-30 mm thick.The Microscal standard cells, which provide humid- ity control, now offer facilities for the light fastness testing of samples in contact with liquid-phase water. These options can be fitted to existing instruments. Microscal Ltd., 20 Mattock Lane, Ealing, London, W5 5BH.Ultra-pure Water System The Vaponics Type 1 system produces ultra-pure water from demineralised or distilled water. The system employs a three-layer, single cartridge, resulting in a compact design suitable for bench or wall mounting. The cartridge holder includes a battery-operated, temperature- compensated purity meter, which has a calibra- tion check facility and indicates purity in terms of resistivity. The scale is calibrated in MQ cni from 0.05 to 10 with 1 at the mid-point. The cartridge removes chlorine, high relative mole- cular mass organic materials, colloidal silica, hydrous oxides of iron and dissolved inorganic impurities.The disposable membrane filter removes particles larger than 0.22 pM, or optionally, 0.45 pM.Flow-rates of up to 60 gal 11-l (272 1 h-l) can be handled a t up to 30 lb in-2 (2.1 kg cm-2). Stanmore Scientific Systems, 9 Stanmore Hill, Stanmore, Middlesex, HA7 3DP. Vacuum Pump A portable, hand-operated vacuum pump is now available with a pumping capacity of approxi- mately 15 ml stroke-l and an ultimate residual pressure of 170 mbar. A. Gallenkamp and Co. Ltd., P.O.Box 290, Technico House, Christopher Street, London, EC2P 2ER. Dispensers Three Brand Dispensette dispensers are now available, covcring the ranges 0.4-2 ml, 1-5 ml and 2-10ml. They can be mounted on most screw-necked reagent bottles, and have flow paths of chemically resistant materials, such as borosilicate glass, PTFE and platinum - iridium. A. Gallenkamp and Co. Ltd., P.O. Box 290, Technico House, Christopher Street, London, ECBP 2ER.Dispensing Pipettes A selection of microlitre dispensing pipettes by Brand is now available, enabling volumes in the range 5-1 000 pl to be dispensed accurately. With a disposable tip attached, the assembly has an over-all length of 270 mm. It is operated by pressing, releasing and re-pressing a button on the top of the pipettor body.An insulating jacket minimises any effect created by hand heat. A. Gallenkamp and Co. Ltd., P.O. Box 290, Technico House, Christopher Street, London, EC2P 2ER. Dilutor A newly available Brand dilutor offers a choice of dilutions with an adjustment range of 1-5 mlNovember, 1978 EQUIPMENT NEWS 317 for the diluting reagent and 0.05-0.5 ml for the sample. It is manufactured from chemically resistant materials, borosilicate glass, PTFE, fluorocarbon and platinum - iridium.The dilutor is operated by dipping the nozzle into the sample t o be diluted and raising the outer plunger housing. The over-all dimensions are 30 x 70 x 130mm and the dilutor can be mounted on most screw-necked bottles. A. Gallenkamp and Co. Ltd., P.O. Box 290, Technico House, Christopher Street, London, EC2P 2ER.Wash Bottle A hand-held, trigger-operated, 600-ml, gradu- ated polythene wash bottle is available. The wash bottle head can be adjusted to provide any required output from a powerful jet to a fine spray. The materials of construction are polyethylene, polypropylene, polyacetal, nylon and stainless steel. A. Gallenkamp and Co. Ltd., P.O.Box 290, Technico House, Christopher Street, London, EC2P 2ER. Filtration Cartridges A range of cartridge filters in pleated form, for grossly contaminated bulk fluids as well as end- point critical filtration, is announced. The CP and CW series of cartridges are available in 25 and 78-cm lengths with a varying filtration area per cartridge (up to 1.4 m2) and providing flows for single elements up to 4 000 1 h-l under a differential pressure as low as 0.13 bar.The cartridges can be used in multi-tube arrange- ment for high volume filtration, even at micro- metre and sub-micrometre levels. Millipore (UK) Ltd., Millipore House, Abbey Road, London, NWlO 7SP. Gas Chromatography - Mass Spectro- metric System The HP 5992 gas chromatograph - mass spectro- meter is a more powerful version of the earlier desk-top computer controlled instrument, offer- ing automatic valves, a higher ion source temperature, automatic tuning, an efficient hyperbolic quadrupole mass filter, an electron- multiplier detector and a microprocessor- controlled gas chromatograph, to provide quantitative and qualitative identification of unknown chemical compounds.The instrument can carry out on-line library searches during data acquisition in order to identify the compon- ents.Hewlett-Packard Ltd., King Street Lane, Winnersh, Wokingham, Berkshire, RG11 5AP. Headspace Sampler for Gas Chromato- The HS6, a headspace sampler for gas chroma- tography, can perform headspace analyses semi- automatically. The system has a capacity of six samples, providing adequate time for temperature equilibrium to be reached.Samples can be either solids or viscous liquids. The HS6 can be fitted to existing instruments, and is thermostatically controlled to better than 0.1 "C over a temperature range +40-+190 "C. A 5-s injection time is automatically controlled. Perkin-Elmer Ltd., Post Office Lane, Beacons- field, Buckinghamshire, HP9 1Qh.graphy Microprocessor Controller for Thermal Analysis The System 4 microprocessor controller for thermal analysis can store, and recall by simple key strokes, complete programmes for the TGS- 2 thermogravimetric and TMS-2 thermo- mechanical systems. System 4 contains three built-in programmes, offering nine user-definable programmes, one working and eight in memory. Perkin-Elmer Ltd., Post Office Lane, Beacons- field, Buckinghamshire, HP9 1QA.Infrared Air Monitor The Miran 801 microcomputer-controlled ambi- ent air monitor can measure up to ten potentially hazardous gases and vapours a t 12 or 24 remote locations. It can be programmed on a con- tinous 24-h basis for up to ten infrared-absorb- ing gases; these include more than half of the (about 400) gases declared hazardous by OSHA.The concentration of each component is printed out directly, in parts per million, and the sampling location identified. High-concentra- tion alarms are included. For division-2 explosion-proof areas, the moni- tor can be supplied in a purged enclosure (ISA Type 2 purging) with the data, presentation removed to a non-hazardous area. Foxboro Analytical, Division of The Foxboro Company, Wilks Infrared Center, P.O.Box 449, South Norwalk, Connecticut, 06856, USA. Ultraviolet - Visible Syectrophotometer A new ultraviolet - visible scanning spectro- photometer, the SP8-200, combines micropro- cessor control and data handling, a high resolution optical system and a large sample chamber and a wide, 185-950 nm, measuring range. A comprehensive choice of modular options and accessories is available.Pye Unicam Ltd., York Street, Cambridge.318 EQUIPMENT NEWS Proc. Analyt. Div. Chern. SOC. Ultraviolet - Visible Spectrophotometer The Spectracomp 601 is a double-beam, ultra- violet - visible spectrophotometer controlled by a microprocessor. The four cells in sample and reference compartments are provided with magnetic stirring, and are programmable from ambient temperature to 45 “C with digital temperature readout.Absorbance values can be converted to concentration. Single wave- length measurement, spectrum display, kinetic analysis and user-dictated programmes are supplied. Erba Science (UK) Ltd., 14 Bath Road, Swindon, Wiltshire, SN1 4BA. Liquid Chromatograph The 1084 Liquid Chromatograph can now be extended to include variable ultraviolet - visible detection and automatic method development and multi-sample analysis.The integrated modular package is designated the HP1084B. Hewlett-Packard, P.O. Box 529, Van Heuven Goedhartlaan 121, Amstelveen 1134, The Nether- lands. Enzyme Analysers A microprocessor-based Eppendorf photometer, type PCP 6121, is now available in the UK.This photometer can store up to 12 routine kinetic enzyme methods, all of which can be recalled or changed. Enzyme activity is constantly monitored and linearity checked for the duration of the pro- grammed measuring interval. The activity, in U l-l, appears automatically on the large digital display. Anderman & Co., Central Avenue, East Molesey, Surrey, KT8 0 9 2 .Turbidity Measurement by Nephelometry The Model 40 nephelometer now available offers meter or digital display with two ranges, 0-10 and 0-100 NTU (nephelometric turbidity units), with a detectable limit of 0.01 NTU. Techmation Ltd., 58 Edgware Way, Edgware, Middlesex, HA8 SJP. Recorders The MFE 1000 series is a new line of packaged strip-chart recorders, with speeds ranging from 1 mm h-1 to 100 mm s-1.From 1- to 8-channel configurations are available. Recording chan- nels are 50 mm wide, except for the 8-channel units in which they have a width of 40 mm. Techmation Ltd., 58 Edgware Way, Edge- ware, Middlesex, HA8 8JP. Magnetic Flow Meters A range of detector heads, Type VTA, has been added to the Veriflux series of electromagnetic flow meters for conductive fluids, and is avail- able in 16 different sizes.The velocity through a known bore is measured by means of monitoring the voltage developed by the liquid passing through a mag- netic field, thus giving no obstruction to flow, no loss of head and immunity to variations in density, viscosity, pressure and temperature. Type VTA detector heads are available for pipe sizes from 32 to 150 mm (1; in to 6 in).They are suitable for liquids and slurries with conductivities down to 1 mS m-3 (10 pmho ~ m - ~ ) . Kent Instruments Ltd., Biscot Road, Luton, Bedfordshire, LU3 1AL. Chromatography Valve A chromatography valve for use in any process or laboratory chromatograph using automatic sampling or column switching is announced. The pneumatically operated, multi-port valve is suitable for both gas and liquid sample handling, having a long working life and maximum operat- ing temperature of 225 “C.Stainless steel 316 is standard, with Hastelloy “B” or “C” also available. Filled PTFE is used for the sliding transfer pad. The valve is available with from four to ten connection ports, in 1/16 in or 1/8 in 0.d. tubing, and is remotely operated by a 2 bar (30 p.s.i.g.) air supply.Pye Unicam Ltd., York Street, Cambridge. pH Meter The PW 9410 pH meter now available provides accurate pH measurement in a compact and simple-to-use instrument. The PW 9410 is compatible with the established Pye - Ingold range of electrodes and accessories. Pye Unicam Ltd., York Street, Cambridge. Miniature Radiation- survey Meters A number of radiation intensity and radiation contamination detection instruments have been developed that fit into the palm of the hand, have accuracies comparable with full sized instruments, operate on 9 V batteries for 100 h or more and can detect alpha, beta and gamma radiation.Dosimeter Corporation of America, 6196 Interstate Circle, Cincinnati, Ohio 45242, USA. The units weigh less than 1 lb.Ion Beam Thinning Device A small and universal ion beam thinning device is announced. Electron microscope specimens can be ion-thinned to electron transparency in the Microrapid within an hour or less. The Microrapid consists of a modified BllW, water-November, 1978 EQUIPMENT NEWS 319 cooled, saddle-field ion source, which produces a powerful ion beam concentrated on t o a speci- men located adjacent to the water-cooled front cathode of the ion source.Automatic termina- tion is provided in order to protect the specimen. It can be mounted in an existing high vacuum coating unit. A pumping speed of 100 1 s-l is needed with a vacuum of better than lo-* Torr. Ion Tech Ltd., 2 Park Street, Teddington, Middlesex, TW11 OLT. PTFE Chemical Filters A new PTFE Fluorogard cartridge can be used for a wide range of chemicals, including con- centrated acids and alkalis.The cartridges are of pleated construction in order to provide a high surface area [4.645 cm2 per 30 cm (cart- ridge)], removing contaminants larger than 0.2 pm (type CWFG) or 1.0 pm (type CWFA) from liquids or gases. The PTFE and poly- propylene components provide adequate chemi- cal compatibility.Millipore (UK) Ltd., Millipore House, Abbey Road, London, NWlO 7SP. In-line Filter The FB 799 in-line filter is designed for perman- ent mounting directly in the pipeline, and ele- ment changes can be carried out without dis- turbing pipework connections. The casting and cover are of mild steel, and filter elements available include felt, paper, epoxide-bonded glass fibre and metal gauze.The FB 799 has a test pressure of 225 p.s.i.g. and a nominal working pressure of 150 p.s.i.g. The nominal flow rating is 200 gal min-l, but this figure may be exceeded with particular element - fluid combinations. British Filters Ltd., Thames Industrial Estate, Fieldhouse Lane, Marlow, Buckingham- shire. Portable Digital Thermometers A new series of battery-powered digital thermo- meters has been announced.Twelve versions of the Lenton LTD800 series are available, and are powered by HP7 or MN1500 manganese alkaline batteries. The LTD800 series has been designed for use with NiCr/NiAl, Cu/Con, Fe/Con and Plt/Plt and Rhdm thermocouples, and platinum or nickel resistance probes, and therefore covers the temperature range from -150 to + 1750 "C.Thermocouple instruments are supplied com- plete with a naked bead probe, and have fully automatic cold junction compensation. Re- chargeable batteries are also available. Lenton Thermal Designs Ltd., 68 Cannock Street, Leicester, LE4 7HR. Vacuum Photodiodes A range of vacuum photodiodes covering the spectral range 180-1 100 nm with a variety of photocathodes including S1, S4, S 5 and S23 is now available.The narrow spectral ranges are suitable for monitoring ultraviolet radiation in the presence of high ambient backgrounds. Both end- and side-window configurations are available. EM1 Electron Tubes, Blyth Road, Hayes, Middlesex. Multimeter The DMM9 is a 4Q digit, 20 000 count unit with a basic accuracy of &0.05%.Gould Advance Ltd., Instrument Division, Roebuck Road, Hainault, Essex, IG6 3VE. Environment Test Chamber The HCL is a self-contained unit designed for bench mounting, available in 1 5 , 30- and 45-1 capacities. All operate over the air temperature range -70 to +200 "C. Climaire Air Conditioning Ltd., Apsley House, Apsley Road, New Malden, Surrey. Modular Water Purification System Elgastat Spectrum water purifiers use nuclear- grade resins to provide ultra-pure water in the relatively small volumes required for ordinary commercial use.Producing up to 120 1 h-l, the new purifiers consist of a mixed bed de-ioniser containing the nuclear grade, or alternatively, strong mix resins which remove mineral impuri- ties, to which can be added upstream cartridges of activated carbon, organic scavenging resins, colloidal removable resins or a selection of pre- flow or carbon composite filter cartridges and downstream a de-oxygenating cartridge and 0.22- and 0.45-pm filter cartridges.A water quality of better than 10 MQ cm (0.1 pS) resistivity from potable water is claimed for the apparatus. Elga Products Ltd., Lane End, Buckingham- shire, HP14 3JH.Literature The revision of BS3996 has now been published to include the full international range of colour coding for one-mark and graduated pipettes, and test methods for assessing the durability of the enamels based on their resistance to deter- gents and acid solutions. The UK has proposed that these test methods should be included in320 EaUIPMENT NEWS PYOC. Analyt.Div. Chem. SOC. IS01796. ville Road, London, N1 9ND. BSI Sales Department, 101 Penton- The first four sheets in a new series of product application sheets demonstrating end-uses of Techne products are now available. They describe uses in chemical oxygen demand determination by two techniques, in thermal insulation testing and in pitch evaluation, and are numbered respectively L1, L2, L3 and L4.Techne Cambridge Ltd., Duxford, Cambridge, CB2 4PZ. The up-to-date range of gas-detector tubes for use in precision gas-detector systems is contained in the Gastec publication. D. A. Pitman Ltd., Mill Works, Jessamy Road, Weybridge, Surrey. A brochure describes the use of the Miran-80 computing quantitative analyser. Foxboro- Wilks Inc., P.O. Box 449, South Norwalk, Conn.06856, USA. A new brochure covers the range of accessories for capillary column gas chromatographs. Scientific Glass Engineering (UK) Ltd., 657 North Circular Road, London, NW2 7AY. The Spring 1978 edition of Telsec News features the use of a Lab X-200 X-ray spectrometer for copper analysis 600 m underground. The addi- tion of an automatic programmed goniometer to the TXRF X-ray spectrometer is also described.Telsec Instruments Ltd., Sandy Lane West, Littlemore, Oxford. Technical Information Leaflet-General 1 gives an introduction to and brief general description of the Health & Safety Laboratories and their range of activities. Health & Safety Laborator- ies, Health & Safety Executive, Red Hill, Sheffield, S3 7HQ. An advanced information bulletin on two new X-ray fluorescence analysis systems is available.Link Systems, Halifax Road, High Wycombe, Buckinghamshire, HP12 3SE. An illustrated brochure (Pub. No. 23-5952- 5809) describes the Model 5958A gas chromato- graph - mass spectrometer and data system. Hewlett-Packard Ltd., King Street Lane, Winnersh, Wokingham, Berkshire, RGl 1 5AR. A booklet entitled “Specific Detectors for Gas and Liquid Chromatographs” is available.Techmation Ltd., 58 Edgware Way, Edgware, Middlesex. The complete line of Miran portable ambient air analysers is described in a recent brochure. Foxboro-Wilks Inc., 140 Water Street, South Norwalk, Conn. 06856, U.S.A. The March, 1978, edition of the Kent Technical Review contains articles on a process computer system for chemical manufacture (soda-ash), a chemical monitoring laboratory and a device to enable closed-circuit television cameras to neutralise the dazzle from a bright light source.George Kent Ltd., Luton, Bedfordshire, LU3 2BR. The broad line of currently available analytical instruments is detailed in a new brochure. Perkin-Elmer Ltd., Post Office Lane, Beacons- field, Buckinghamshire, HP9 1QA.A note describing benzene in air analysis by charcoal-tube absorption, desorption by carbon disulphide and subsequent gas-chromatographic determination is available and is numbered AN228-6. Hewlett-Packard Ltd., King Street Lane, Winnersh, Wokingham, Berkshire, RGll 5AR. The January 1978 edition of NMR News (No. 17) describes the effects on nuclear magnetic resonance spectra of the presence of para- magnetic materials.Perkin-Elmer Ltd., Post Office Lane, Beaconsfield, Buckinghamshire, HP9 1QA. The Spring 1978 issue (Volume 8, No. 1) of Analytical Advances features the use of the HP 79875A variable wavelength detector in multi-component liquid-chromatographic analy- sis. Hewlett-Packard Ltd., King Street Lane, Winnersh, Wokingham, Berkshire, RGll 5AR.Rank Hilgev News No. 13 describes improve- ments made in the performance of the Atomspek 1580 and Chromaspek. Rank Hilger, West- wood, Margate, Kent, CT9 4JL. Information on Porter precision products for control and measurement of gases and liquids at low flow-rates is included in a recent brochure. Scientific Glass Engineering (UK) Ltd., 657 North Circular Road, London, NW2 7AY.A visual aids handbook for the Porosimeter, Series 200, describes the connections between the Porosimeter, the digital reduction unit and the recorder, plus the calibration and operation of the instrument. A further section deals with sample weighing and outgassing.November, 1978 WHO REPORT 32 1 An additional booklet on applications shows typical pore size distribution curves of a wide range of materials. Erba Science (UK) Ltd., 14 Bath Road, Swindon, Wiltshire, SN1 4BA. A new publication describes the range of port- able instruments for testing dielectric materials. The Micanite and Insulators Co. Ltd., Westing- house Road, Trafford Park, Manchester, M17 IPR. New Materials Test Papers for Serum Cholinesterase The test kits measure the time that elapses while the Acholest paper develops the same colour as that produced in a control paper exposed to the sample at the same time, in order to distinguish between increased, normal, diminished or strongly diminished activities of SCHE (serum cholinesterase). Koch-Light Laboratories Ltd., Colnbrook, Buckinghamshire, SL3 OBZ. Biodegradable Dielectric Fluids Midel 7131 and Midel 7211 are non-toxic, bio- degradable alternatives to polychlorinated bi- phenyl dielectric fluids. Low flammability per- mits their use in critical areas. Midel 7 13 1 also possesses good lubricating properties, and is designed for transformer use. Midel 72 11 is designed for use in capacitors. The Micanite and Insulators Co. Ltd., Westinghouse Road, Trafford Park, Manchester, M17 1PR.

ISSN:0306-1396    

DOI:10.1039/AD9781500315

出版商:RSC    

年代:1978

数据来源: RSC

摘要:

November, 1978 WHO REPORT 32 1 World Health Organization Report The following is a summary report”, prepared by the Working Group on Health Significance of Chemicals Occurring Naturally in Drinking- water of the WHO, of their meeting held in Brussels during March 20th-23rd, 1978. Introduction In collaboration with the Government of Belgium the WHO Regional Office for Europe convened a working group to discuss the health significance of substances occurring naturally in drinking-water, with special attention to the implications to health from the use of desalin- ated and demineralised water.Topics Discussed The Working Group considered the long-term health effects of substances normally or occasion- ally present in drinking-water. Special atten- tion was given t o certain substances that occur in small amounts in water either naturally or through treatment processes such as desalina- tion, demineralisation or water softening. It was recognised that desalinated water is usually corrosive to plumbing and, unless it has been adjusted by the addition or replacement of some of the constituents naturally present in drinking- water supplies, health considerations may make it unsuitable for drinking even though the raw water from which it is prepared may be accept- able.One of the substances of greatest interest is magnesium. Magnesium ions are one of the two main components of what has commonly been called “hardness”i in water. They have recently been recognised as being probably the most important factor in the inverse relationship between death from heart disease and the con- centration of calcium and magnesium ions in drinking-water supplies.Calcium is usually adequately supplied by food, in contrast to magnesium. Calcium, however, has an import- ant technical function in drinking-water supply systems. Water that is undersaturated with calcium carbonate is considered to be aggressive and can leach metals such as lead, cadmium, copper and zinc from pipes and plumbing.Water saturated with calcium carbonate is stabilised and has a greatly reduced potential for corrosion. Many natural waters contain calcium and magnesium in a ratio of about three to one. Stabilised water, containing calcium and magnesium ions a t about this ratio appears to be satisfactory from both health and technical aspects.The Working Group reviewed other elements found in drinking-water. In every instance it was concluded that there was, a t present, in- sufficient justification for recommending the addition of any other element to water that is deficient in minerals. In most instances, the daily intake of minerals from food greatly exceeds the amounts contained in drinking- water.Sometimes, in order to provide mag- nesium and calcium ions, it will be useful to add all of the ions present in a naturally mineralised water when such water is blended with product * A comprehensive final report on the meeting will be issued later. t “Hardness” is an imprecise term and should be avoided. It refers t o the number of polyvalent ions in water, quantitatively, the two main ones being calcium and magnesium.322 OBITUARY water of low mineral content.In such instances, of course, the resultant blend should be stabil- ised and should meet the appropriate drinking- water standards. However, in some special instances such as zinc, if a deficiency is observed it would be better for the supplement to be given through food. Sodium ions are present in some drinking- water a t levels that are considered to be excess- ive, a t least for certain segments of the popula- tion.The Working Group deferred any recom- mendations on this matter to a subsequent WHO Working Group a t The Hague (May lst-5th, 1978), which was to discuss sodium and chlorides in drinking-water. Recommendations The Working Group recommended that special attention should be given to further studies of the effects of magnesium in drinking- water on human health, including the sudden infant death syndrome.Moreover, further studies are needed on the absorption and bio- availability of minerals in food and water, as it is now apparent that water can provide a significant fraction of some of the mineral requirements of the human body. Changes in the content and availability of minerals pro- duced by modern methods of food preparation, mainly cooking, should be evaluated. The mineral content of a local diet should be con- sidered when changes in the mineral content of the drinking-water are contemplated. Pvoc. Analyt. Div. Chern. SOC.

ISSN:0306-1396    

DOI:10.1039/AD9781500321

出版商:RSC    

年代:1978

数据来源: RSC

摘要:

322 OBITUARY Pvoc. Analyt. Div. Chern. SOC. Obituary Douglas William Kent - Jones Douglas William Kent-Jones was born in Camberwell in 1891 and was educated at Mercer’s School and then King’s College, London, where he graduated as a BSc with first-class honours in chemistry in 1912. In 1913 he passed the Branch E examination of the Institute of Chemistry and obtained a, post as chemist with Lactose Ltd.in Tipperary. A few months later, after the declaration of war in 1914, he joined the Public School Brigade (Royal Fusiliers 19th Battalion) and the next year was transferred to one of the four Companies R.E. formed to be employed in gas-offensive operations on the Western Front and saw action at Loos. A year later, when the four Companies were expanded to a Brigade, he was commissioned in “C” Company and was mentioned in dispatches.In 1917, the year in which he was elected to the Fellow- ship of the Institute of Chemistry, he transferred to the Royal Flying Corps as an Observer and early in 1918 was shot down and remained a prisoner in Germany until the end of hostilities. In 1919 he became chemist to Woodlands Ltd., a firm in Dover that manufactured ammonium persulphate electrolytically for use as a flour improver, and during the eleven years with this firm he progressed through a Directorship to Managing Director.One of the founders of the firm was senior partner in a family flour mill that was adjacent to the firm’s laboratories, and this led Kent- Jones to interest himself in cereal science ancl tech- nology to such effect that within 5 years he had published “Modern Cereal Chemistry” (a book that is now in its sixth edition and an inter- nationally recognised cereal textbook), had become Chief Examiner in Breadmaking t o the City and Guilds of London, a post that he held until 1945, and had invented a viscometric procedure for measuring the “strength” of flour, which was very succesfully marketed throughout the milling industry as the “K- J Strength Tester.” He ther, turned his atten- tion to the effect of heat upon cereals and the outcome of these pioneering researches was a PhD of London University in 1926 for a thesis entitled “A Study of the Effect of Heat upon Wheat and Flour, Especially in Relation t o Strength” and the development of a machine for the automatic heat-treatment of flour in a mill, which was marketed as the “K-J Con- tinuous Thermo-Process.” In 1930, Woodlands’ patents ran out and the firm retired from business, whereupon Kent- Jones, with the present writer as a junior partner, took over the Woodlands laboratories and started a consulting practice specialising in cereals under the title “The Dover Labora- tories.” Five years later he published “The Practice and Science of Breadmaking” and in 1938 became Professor holzovis causa of the Institut des Industries de Fermentation, Bruxelles, and also of the Institut Superieur de Fermentation, Gand, and was awarded the Effront Medal.In 1940, because of the likeli- hood of Dover becoming the target of cross- Channel shelling, the equipment and staff of the laboratories were transported, during Dunkirk week, from Dover to rented premises in London whence, with a change of name t o “D.W. Kent-Jones & A. J. Amos,” the practice operated for the next 10 years. During that time the scope of the practice was expanded to cover all foods, drugs and, in particular, microbiological assays. However, cereals re-November, 1978 OBITUARY 323 mained Kent- Jones’ primary interest and when he gave the Royal Society of Arts’ Cantor Lectures in 1949 he chose as his subject “Bread.” In 1950, the practice moved into new laboratories, which it had had built in Willesden, and soon after the move Kent- Jones was primarily responsible for the basic principle and the development of an instrument capable of measuring the grade colour of flour, an instrument now in daily use in all British flour mills and in many mills overseas.In the early thirties, when the practice was at Dover, it undertook a research programme for the inventor of gluten-enriched bread and this led, in 1935, to Kent-Jones becoming a founder Director of a Company, Procea Pro- ducts Ltd., set up to exploit the invention commercially; in 1952 he became Chairman of the Company and continued in that office until 1965.Kent- Jones’ active participation in the administration of scientific societies commenced in the Dover days; he was a member of the Council of the Institute of Chemistry, 1928- 1931, and of the Council of the Society of Public Analysts, 1930-1931. His services to these two bodies, under their new names of the Royal Institute of Chemistry and the Society for Analytical Chemistry, were renewed after the move to London.He served the SAC as a member of Council (1942-1943, 1945-1946, 1950-1951), as a Vice-president (1947-1948, 1952-1953) and as President (1953-1955), whilst his services to the RIC were member of Council (1946), Honorary Treasurer (1946-1953), Vice-president (1953-1955), President (1955- 1957) and Censor (1953-1966).During his Presidency of the SAC he was serving also as Honorary Secretary of the Food Division of the Applied Chemistry Section of the Inter- iiational Union of Pure and Applied Chemistry. In 1962, he became a member of Council of the newly formed British Industrial Bio- logical Research Association. Kent- Jones retired from the practice at the start of 1966, 6 months before his 76th birthday, but continued to serve on the Council of BIBRA of which he was appointed Chairman a few months later.In 1970 he became President of the Association and, on retiring from the office 2 years later, he was made the Associa- tion’s first Honorary Member. In recognition of the contributions he had made to the science and the technology of foods, and particularly cereals, during his professional life he was made an Honorary Member of the Flour Milling and Baking Research Association, the American Association of Cereal Chemists, the Bread Research Institute of Australia and an Honorary Fellow of the Institute of Food Science and Technology.In 1971 he was the Medallist of the Society of Chemical Industry and in 1974 he received the OBE for services to the food industry.In addition to the two books of which he was the senior author he had published some 40 papers in scientific journals. Kent- Jones made a number of overseas visits covering, in addition to Europe, USA, Canada, South Africa, Australia and New Zealand; the investigation into bread quality in New South Wales that he made a t the request of the baking industry of that State in 1947 culmin- ated in the formation of the Bread Research Institute of Australia.Kent-Jones was a member of the Savage Club, a Liveryman of the Worshipful Society of Apothecaries of London and a Freeman of the City of London. Until arthritis took its toll his active relaxation was golf and he was for a long time President of his Golf Club.To all his interests and to all the tasks that he undertook Kent-Jones brought boundless enthusiasm and energy. Just as in the cereal field his dedication and constant searching for new ideas were responsible for advances in analytical procedures and technical equip- ment that bear his name, so too did the same two qualities leave mementoes of the long services that he gave to the scientific societies to which he was devoted.There is no need to recount all that he did for the SAC over a period of nearly 40 years but its value is summed up in the inscription on a presen- tation made to him on his retirement; i t read “To K-J. From the Society for Analytical Chemistry which has gained much from his wise counsel and guidance over many years.” However, just as he became absorbed in whatever task he had on hand during working hours, so did he give all his attention to enjoy- ment during his relaxation; he loved good food, good drink and jovial companionship and he was never happier than when he was enter- taining.He was, by nature, a kindly and generous person, who was thoughtful for the comfort and well-being of others and always ready to give advice or practical help to those in trouble.He was a widower and had no children but there are very many in this country and overseas, friends, acquaintances and business associates, who will be saddened by the know- ledge that K- J , as he was affectionately known so widely, is no longer with us. A. J . AMOS324 IUPAC REPORT IUPAC Report Proposed Terminology and Symbol for the Quantity Representing the Transfer of Solutes from One Solvent to Another The Commission on Electroanalytical Chemistry of the Analytical Chemistry Division of IUPAC has produced a report on this subject which has been prepared by B. Tremillion and J. F. Coetzee. The report appeared in Puve and Applied Chemistry, Vol. 50, No. 6 (1978), and reprints of it can be obtained from Pergamon Press Ltd., Headington Hill Hall, Oxford, OX3 OBW. Proc. Analyt. Div. Chem. SOC.

ISSN:0306-1396    

DOI:10.1039/AD9781500322

出版商:RSC    

年代:1978

数据来源: RSC

摘要:

324 IUPAC REPORT Proc. Analyt. Div. Chem. SOC. and instrumental requirements of atomic absorption ; flame and resistively heated atom reservoirs ; hydride generation ; optical systems ; criteria for instrument design ; optimisation of instrument conditions ; interference effects ; methods of calibration ; applications ; theory and applications of d.c. and inductively coupled plasma emission methods ; atomic fluorescence ; molecular emission cavity analysis ; and candoluminescence.Further details can be obtained from Miss J . M. Brown, Department of Chemistry, Loughborough University of Technology, Loughborough, Leicestershire, LEll 3TU. Gas Chromatography Januavy 8-12, 1979, Loughbovough The aim of the course is to present an up to date account of gas chromatography and is designed to provide a rapid introduction to the theory and practice of the technique.The course includes practical sessions and will be held at the University of Technology. For further information contact Miss J. M. Brown, Chemistry Department, Loughborough University of Technology, Loughborough, Leicestershire, LEll 3TU. Process Analytical Instrumentation March 19-23, 1979, Coventvy The continuing growth in use and importance of process analytical instrumentation in various sectors of industry has created a need for many personnel to acquire a background knowledge of the principles, capabilities and applications of such instruments.To help satisfy this need the Institute of Measurement and Control is now planning its fifth School on Process Analytical Instrumentation, to be held at the University of Warwick.The lecturers will all have considerable industrial experience in their subjects and lecture notes will be provided. In addition to the lectures, there will be small discussion groups to enable participants to Atomic Absorption and Emission Spectro- discuss problems, ask questions and talk to metry lecturers. The School will end with a forward- looking review paper.December 11-15, 1978, Loughborough In general, the following groups will benefit from attendance at the School: those new to The course, which is to be held at the University the instrument field ; those with some experi- of Technology, will cover the following topics: ence in instrumentation who wish to broaden origin of atomic spectra ; fundamental principles their knowledge ; contractors, managers and CoursesNovember, 1978 CONFERENCES AND MEETINGS others indirectly concerned with analytical instruments. In all instances at least HNC qualifications or significant experience in instru- mentation (or its management and installation) are seen as the most useful starting points.The subjects covered by the School include a comprehensive survey of the methods currently used, covering the basic principles, applications and limits, advantages and dis- advantages and practical examples of use in process plants for control, safety and environ- mental protection. In addition, newer types of analysers are reviewed and special emphasis is given to sampling, calibration, electrical safety, instrument evaluation and maintenance. Further details are available from the Deputy Secretary, The Institute of Measurement and Control, 20 Peel Street, London, W8. 325

ISSN:0306-1396    

DOI:10.1039/AD978150324b

出版商:RSC    

年代:1978

数据来源: RSC

摘要:

November, 1978 Conferences and Meetings CONFERENCES AND MEETINGS 325 EMAG'79 September 3-6, 1979, Brighton The Electron Microscopy and Analysis Group of The Institute of Physics is organising EMAG '79 at the University of Sussex. The conference is the next in the series EMAG '75 (Bristol) and EMAG '77 (Glasgow). As in previous confer- ences, the aim will be to present the most recent developments in electron microscopy to an audience of primarily physical scientists, (although some biologists attend), and will emphasise developments of technique rather than applications.Further details will be available later in 1978 from the Meetings Officer, The Institute of Physics, 47 Belgrave Square, London, SWlX SQX. FA- Amsterdam ; International Conference on Flow Analysis Septevvtbev 11-13, 1979, Amsterdam, The Nether- lands A three-day conference on flow analysis will be held in Amsterdam.The program will cover a wide and representative selection of current research on all aspects of flow analysis. The topics will be: instrumentation design for flow analysis ; possibilities for complete auto- mation; new detection systems; theory of flow analysis ; and its application in industrial, environmental and clinical analysis.A first announcement and a preliminary registration form are available a t the secretariat : Secretary FA-Amsterdam, Laboratory for Analytical Chemistry, University of Amsterdam, Nieuwe Achtergracht 166,1018 WV Amsterdam, The Netherlands. Euroanalysis IV August 23-28, 1981, Helsinki, Finland The next Euroanalysis Conference is to be organised by the Association of Finnish Chemi- cal Societies. The Conference will be held a t Helsinki University of Technology, which is situated a t Espoo near Helsinki. For a copy of the first circular contact the Association of Finnish Chemical Societies, Mr. Veikko J. Velamo, Executive Secretary, Pohj . Hesperi- ankatu 3B10, SF-00260 Helsinki 26, Finland.

ISSN:0306-1396    

DOI:10.1039/AD9781500325

出版商:RSC    

年代:1978

数据来源: RSC