ISSN:0144-557X    

DOI:10.1039/AP98724FX001

出版商:RSC    

年代:1987

数据来源: RSC

摘要:

2 ANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 Honorary Publicity Secretary‘s Column There are a couple of trite sayings that might sum up my period of office as Honorary Publicity Secretary, depending on one’s point of view. One concerns the ultimate fate of all beneficent objects and the other the apparent temporal contrac- tion that occurs when undergoing a pleasurable experience. As “all good things must come to an end” and “it’s amazing how time flies when you’re enjoying yourself,” I am just a little surprised to realise that this is my last column. By the time this article is publi- shed my successor, Dr. Clive Jackson, well known to many readers, I am sure, through his sterling work as Honorary Secretary of the Automatic Methods Group, will be well into his stride. I expect he will find some way of telling you what he plans to do over the next 4 years.I have not made any secret of the fact that I have been concentrating on the public relations side of the job and, in particular, concentrating on the next generation of scientists, although the cur- rent generation has not been entirely neglected. Both the Schools Lectures and the glossy brochure seemed to go down quite well, and I hope that the video and the RSC Paperback will as well, when they eventually see the light of day. The work of the Analytical Methods Commit- tee has been brought to the attention of a wider section of the scientific community through the medium of several articles and the display stand. The new Statistical Sub-committee, under the chairmanship of Dr. Mike Thompson of Imperial College, has pro- duced two reports to be published soon, which should be of interest to all analy- tical chemists.These concern firstly the conduct of co-operative trials (the analy- sis of the same material by different laboratories using different methods, not be confused with collaborative trials in which the same method is used by all participating laboratories), and secondly, limits of detection. As with most AMC work, the reports will appear in The Analyst. Also of general interest is the work of the Instrumental Criteria Sub- committee, under the Chairmanship of Professor Stan Greenfield of Loughbor- ough University. The work on instrumen- tation for analytical atomic spectroscopy continues and a report concerning monochromators for use in emission spec- trometry with ICP sources appear this month in Analytical Proceedings (p.3). The Sub-committee intends to follow up with the topics of gas chromatography and high-performance liquid chromato- graphy. There have been some sugges- tions for new sub-committees. A brief report of the AMC’s activities appears in the Division’s Annual Report of the Council and further information can be obtained from the Secretary, Mr. J. J. Wilson (c/o Burlington House). Professor Greenfield has been busy recently as the meeting of Division Coun- cil in May considered the Report of the Working Party on Groups, which is also under his Chairmanship. Readers will be given more detailed information by another route but in summary, some new Groups will be formed (Chemometrics, Molecular Spectroscopy), some Groups will have their remit broadened and pos- sibly a change of title to reflect this change and some Groups will be wound up.This last category includes the Education and Training Group. However, some of its present activities will continue through the creation of a new Committee of Council to deal with educational matters and the Programmes Committee will have responsibility for the organisation of edu- cational meetings. There are no grounds for analytical chemists to feel complacent about the state of the provision of educa- tion in our subject area, particularly in universities. For example, a recent survey by the Analytical Chemistry Working Party of the Federation of European Chemical Societies (FECS) found that many British university chemistry depart- ments could not identify a single member of staff with responsibility for the teaching of the subject.An excellent summary of the present situation was presented by Dr. Paul Worsfold of Hull University at the SAC 86/3rd BNASS conference in July in the form of a poster display entitled Analytical Chemistry News. The poster was also available in magazine format; anyone wishing to obtain a copy should contact Miss Hutchinson at Burlington House. Several other items were discussed at the May Council, apart from the Groups Working Party Report. The Professional Affairs Board has delayed the implemen- tation of the Indicative Register of Analy- tical Chemists to give time for further consultation. Work on the associated Study Guide has continued though, and this is nearly complete.It was decided that a SAC conference should be held in 1989 and that the venue would be Cambridge. In the meantime, the Programmes Committee has a full programme of Divisional meetings and is planning participation in a number of conferences. These include a joint meet- ing with the Royal Netherlands Chemical Society on “Separations” at Canterbury, March 30th-April lst, 1987. The Divi- sional AGM will take place during this meeting. The Sixth International Sympo- sium on Electroanalysis in Biomedical, Environmental and Industrial Sciences will take place in Cardiff on April 6th- 9th, 1987, and is closely followed by the RSC Annual Congress, just down the road in Swansea, on April 13th-16th. The Analytical Division’s theme will concern mass spectrometry.July 5th-lOth brings the 8th International Meeting on NMR Spectroscopy at Canterbury and a brace of schools lecturers can be seen in action at the Division’s Research and Develop- ment Topics meeting at Strathclyde on July 8th and 9th prior to receiving their silver medals. This continues a Scottish theme as Dr. Robert Chalmers, recently retired from the University of Aberdeen, will deliver the second L. S. Theobald lecture on “The Trouble with Moisture Meters,” with a full supporting pro- gramme on the general theme “Usage and Abusage in Analysis.” This will take place on May 5th in London, while Dr. Allan Ure, similarly recently retired, from the Macaulay Institute for Soil Research in Aberdeen, will deliver the Theophilus Redwood Lecture at the RSC Annual Congress in April. Incidentally, it is now almost certain that the “Macaulay” will not move from Aberdeen, as was announ- ced last year by the Secretary of State for Scotland, although it will be relocated and have something of a change of remit. The Division had expressed its concern over the future of the “Macaulay,” an institute with an outstanding record of analytical achievements. For further information about any of the above items, please contact Miss P. E. Hutchinson, Secretary of the Analytical Division, Royal Society of Chemistry, Burlington House, London W1V OBN. J. F. TYSON

ISSN:0144-557X    

DOI:10.1039/AP9872400002

出版商:RSC    

年代:1987

数据来源: RSC

摘要:

ANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 Report by the Analytical Methods Committee Feature 1. Resolvingpower in the wavelength region of interest 3 Definition and/or test procedures and guidance for assessment Importance Reason Maximum score for highest VI In emission spectrometry it is values of 12AA. AA is the smallest difference between two wavelengths which can be distinguished as two spectral lines (normally separation at half height). Suitable lines pairs for this test are listed in the Appendix. essential to be able to resolve and measure a line of interest in a complex spectrum. Evaluation of Analytical Instrumentation. Part IV. Monochromators for Use in Emission Spectrometry with ICP Sources Analytical Methods Committee Royal Society of Chemistry, Burlington House, Piccadilly, London WI V OBN A method is provided for comparing the features of monochromators for use in emission spectrometry with ICP sources. The Analytical Methods Committee has received and approved the following report from the Instrumental Criteria Sub-committee.Introduction The following report was compiled by the above Sub- Committee of the AMC, which consisted of Professor s. Greenfield (Chairman), Professor E. Bishop, Mr. N. W. Barnett (until July, 1985), Dr. L. Ebdon, Dr. E. J. Newman, Mr. D. Squirrel1 and Dr. P. Smith (until April, 1985) with Mr. C. A. Watson as Honorary Secretary. The purchase of analytical instrumentation is an important function of many laboratory managers, who may be called upon to choose between a wide range of competing systems that are not always easily comparable.The objective of the Instrumental Criteria Sub-committee is to tabulate a number of features of analytical instruments which should be con- sidered when making a comparison between various systems. As is explained below, it is possible then to score these features in a rational manner, which allows a scientific comparison to be made between instruments. The over-all object is to assist purchasers in obtaining the best instrument for their analytical requirements. It is also hoped that, to a degree, it will help manufacturers to supply the instrument best suited to their customers’ needs. No attempt has been made to lay down a specification. In fact, the Committee considered that it would be invidious to do so; rather, it has tried to encourage the purchasers to make up their own minds as to the importance of the features that are on offer by manufacturers.This fourth report of the Sub-committee deals with mono- chromators for use in emission spectrometry with ICP sources. Notes on the Use of this Document Column 1. The feature of interest. Column 2. What the feature is, and how it can be evaluated. Column 3. The Sub-committee has indicated the relative importance of each feature and expects users to decide on a weighting factor according to their own needs. Column 4. Here the Sub-committee has given reasons for its opinion as to the importance of each feature. Column 5 onwards. It is suggested that scores are given for each feature of each instrument and that these scores are modified by a weighting factor and sub-totals obtained.The addition of the sub-totals will give the final score for each instrument. Notes on Scoring 1. (PS) Proportional scoring. It will be assumed, unless otherwise stated, that the scoring of features will be by proportion, e.g., WorstiO to Besth00. 2. (WF) Weighting factor. This will depend on individual requirements. An indication of the Sub-Committee’s opinion of the relative importance of each feature will be given by the abbreviations VI (very important), I (important) and NVI (not very important). A scale is chosen for the weighting factor which allows the user to discriminate according to needs, e.g., x l to x 3 , or x l to x10. The factor could amount to total exclusion of the instrument. 3. (ST) Sub-total.This is obtained by multiplying PS by WF. INSTRUMENTAL CRITERIA SUB-COMMITTEE I%STRUMENT EVALUATION FORM Type of Instrument: Monochromator for Use in Emission Spectrometry with ICP Source. Manufacturer: I4 ANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 Feature 2. Wavelength range 3. Scanning speed (for qualitative analysis) 4. Measurement speed 5. Effect of varying light levels 6 . Stray light Definition and/or test procedures and guidance for assessment ( a ) The instrument must cover the spectral range which encompasses the lines of interest to the user. ( b ) Score additionally for an extended range. Score maximum for a wide range of scanning speeds, which will enable qualitative data to be obtained without the use of excessive amounts of sample.Select two lines near the extremes of the range of interes, and measure the time required to obtain results at both lines with the required precision, including two pre-set background corrections; score accordingly. Using a suitable source, e . g . , a hollow cathode lamp run at higk current or an electrodeless discharge lamp, measure the signal resulting from this high intensity source. Insert a flag filter to reduce the intensity by a factor of 10000 and repeat the measurement. This experiment should be repeated rapidly 20 times and the standard deviation and mean at each level calculated. Various sources should be used to cover the wavelength range of interest. There should be no statistically significant difference between the initial and final reading. Score accordingly.A low pressure mercury lamp should be used. The signal at 253.7 nm should be substantial so that a large amount of light enters the spectrometer. Measurements of this signal at minimum gain should be obtained together with measurements at 252.7 nm and 254.7 nm made at high gain. Score maximum for the minimum ratio of readings at the other wavelengths to those obtained at 253.7 nm. Other wavelengths, particularly short wavelengths, should be interrogated using high gain. mportance VI NVI I I VI VI Reason Nhilst it is obviously necessary or the user to be able to access he lines of interest, it is idvantageous to be able to ,elect other lines of interest, vhich may be used to alter #ensitivity or avoid nterferences. scanning speeds are important f qualitative information is .equired, as too slow a speed nay require excessive amounts If sample solution, while inavailability of slow scanning .ates may lead to loss of nformation.rhis parameter defines the iltimate speed of analysis and will affect the amount of sample Pequired and the economics of 3peration. - [n routine use the photomultiplier tubes will be subjected to rapidly changing light levels and this must not affect the response of the PMT to a given level if quantitative measurements are to be reliable. 4 s well as light loss, stray light xoduces unwanted and qariable background readings. kore PS WF ST PS WF ST PS WF ST PS WF ST PS WF STANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 5 Feature 7 . Light gathering power 8. Wavelength search reproducibility 9.Short-term stability 10. Temperature stability Definition and/or test procedures and guidance for assessment This is the minimum amount of energy that can be detected at a suitable selection of wavelengths covering the instrument's range. Use a calibrated tungsten lamp at the normal source position of the spectrometer, focused by the spectrometer lens on the slit. An iris diaphragm, suitably positioned, will determine the useful solid angle, S, subtended by the source. If the area of the slit is A and the magnification of this image M , the energy passing into the spectrometer is BAS M where B is the spectral radiance of the source (watts steradian-1 cm-2) and S the spectral band width. The diaphragm should be closed until a very small net signal is obtained, the result being expressed as counts per watt.Score maximum for the highest value for this function. Using a stable source, for example, a hollow cathode lamp or discharge lamp, use a normal analytical programme to search for appropriate lines. Repeat 10 times and record the mean signal and standard deviation. Repeat using the minimum scan rate and score maximum for closest agreement between two modes. ~~~ Using a stabilised light source such as a hollow cathode lamp or low pressure mercury lamp, produce a series of readings at one per minute for 30 min. This should be repeated using suitable attenuation to cover the dynamic range of the instrument. The system should be allowed to stabilise between each set of measurements. Score maximum for the lowest standard deviations.Drift should be essentially absent over the period of the measurements. Maximum score for the widest range of ambient temperatures over which the stabilities as determined above can be guaranteed by the supplier/ manufacturer. Importance I VI VI VI Reason The light gathering power of the monochromator will affect the sensitivity of the instrument [see Appendix). [naccurate wavelength settings will cause considerable -eduction of analytical Irecision. [f the monochromator is not itable, within acceptable limits, 'or short periods, it will not be Iossible to obtain useful luantitative results. ~ ~ ~~ ~~ The shorter the temperature .ange over which the nstrument will function at full :fficiency, the more complex md expensive will be the .equired laboratory emperature control system.Scort PS WF ST PS WF ST PS WF ST - PS WF ST6 ANALYTICAL PROCEEDINGS, JANlJARY 1987, VOL 24 Feature 11. Slit geometry and selection 12. Grating 13. Focal length 14. Computer compatibility ( a ) Sophistication ( b ) Output ( i ) High quality graphics (ii) Printer (iii) Report (iv) Plotter formatting 15. Background correction modes Definition and/or test procedures and guidance for assessment Vertical rather than horizontal slits are more compatible with the plasma source geometry. Preference should be given to instruments with a selection of entrance and exit slits. ~~~~~~ ~ ~ The properties that are affected by such considerations as ruled or holographic gratings, blaze angle, etc., are light gathering power and stray light and these have been dealt with under the appropriate headings.The properties that are most affected by focal length, such as dispersion, stability, etc., have been dealt with under the appropriate headings. Score maximum for the greatest extent to which the instrument is under computer control. Further score for ease of use and provision of high level language program access. Score according to availability of each of these accessories and their degree of sophistication Background correction is the compensation for extraneous radiation in the measured intensity of spectral lines such as continuum overlap and stray light. In a rapid scanning instrument it should be possible to correct for background by measurements on either side of the line of interest. Score maximum for systems with maximum versatility, e.g., ability to correct using readings on either side of the line with varied weighting of the measurements or on one side only, and an ability individually mportance I I I-VI depending on circum- stances VI Reason The region of maximum signal to background ratio in a plasma source is a small vertical region which is readily matched by vertical slits, minimising critical adjustment of the source.A choice of slit widths and heights is beneficial in selecting conditions to maximise signal to noise and background ratios to minimise interferences. - A compact, easily operable system which has high speed and capacity greatly assists the operator to obtain accurate results quickly, and also facilitates such items as inter-element corrections, background corrections and calibrations.(j) Method development is often facilitated by visual- isation of spectral profiles. (ii) Quality control requires provision of hard copy. (iii) Very useful in conjunction with management systems. (iv) Complements graphics output for investigation of interferences and systems and methods evaluation. Normally the best correction will be achieved by programming the computer to correct for background by subtracting the mean of the intensities on either side of the line. However, visual inspection using the graphics facility may indicate structured background and certain spectral features may make correction using only one wavelength or using a larger than normal wavelength shift advisable. Score PS WF ST PS WF ST PS WF ST PS WF STANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 7 Feature 16.Dynamic range and mode of integration 17. Speed of quantitative analysis 18. Over-all performance 19. Amenities (a)Bench/floor space/ weight (floor loading) ( b ) Services ( i ) Environmenta control (ii) Electrical (c) Servicing and spares (d) Application support ( e ) Availability of major accessories and updates Definition and/or test procedures and guidance for assessment to set the wavelengths for background correction. ~~ ~~~~ Maximum score should be given for digital integration, with the greatest linear dynamic range. This is mainly determined by the “washout” time of the nebuliserispray chamber employed. This can be evaluated by measuring the time for the signal for 1000 p.p.m.of manganese or other suitable element, to decay to a level at which it has no statistically significant effect upon the precision or accuracy of the measurement of a 1 p.p.m. solution. This parameter must be used with caution as the use of a different nebuliserispray chamber may significantly change the assessment. A test procedure is outlined in the Appendix. It is appreciated that most users will only perform part of the exercise because of limitations of time. Self-explanatory. Score maximum for minimum requirements for environmental control (room temperature and humidity) necessary to enable the instrument to operate within its specification. Score maximum for compatibility with existing electrical supply, with regard to both loading and stability.Enquire in detail as to local arrangements and score accordingly. Enquire as to availability of applications support in field(s) of interest and score accordingly. Enquire about manufacturers’ policy on updating software and compatibility of present and future accessories; score accordingly. Importance VI I VI Varies with users circum- stances but may be VI VI Varies with users circum- stances VI I I Reason For the stable signal produced by the ICP, digital integration following A-D conversion is the most accurate method. The source has a linear dynamic range of 5-6 orders of magnitude and the integrator should at least match this. Instruments for routine use may require a high sample throughout for economic reasons. It is essential that any such required rate can be met by the instruments under :onsideration. Evaluation of the over-all system is essential to ensure that performance of individual :omponents is not degraded when they are integrated into a zomplete system.The instrument must be laboratory compatible or else Zxpensive alterations will be required. 4dditional installation costs nay be considerable, if close :ontrol of environmental factors is required. 4dditional power requirements nay significantly increase nstallation costs. Zost of spares, servicing and Ilowntime may severely alter iver-all running costs. rime and facilities for method levelopment may add jignificant costs, especially if :raining facilities are scant. Future analytical requirements. - Score - PS WF ST PS WF ST - PS WF ST PS WF ST PF WF ST PS WF ST PS WF ST PS WF ST PS WF STANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 Feature cf) Training facilities and documentation 20.Value for money Points perf Definition and/or test procedures and guidance for assessment Enquire as to local arrangements for operator training and available documentation and score accordingly. Sum of the previous sub-totals divided by the purchase price of the instrument. Subject to proportional scoring and weighting factor as for previous features. Include ST in grand total. Importance I I APPENDIX EVALUATION OF OVER-ALL PERFORMANCE Although the performance of various components of the instrument are evaluated individually it is desirable to make some evaluation of the over-all system performance. It is also appreciated that light gathering power (test 7) can be as easily tested by an evaluation of sensitivity as in this test of over-all performance. The items for consideration can be summarised as: precision; sensitivity (detection limit, related to sensitivity and precision); accuracy (comparison of subsequent readings with calibration value); drift (calibration shift); freedom from spectral inter- ference (resolution); linear dynamic range and analytical range.A reasonable number of lines/elements should be evaluated and these should be selected to cover the normal range of the instrument. It is essential that the same lines should be evaluated for each instrument under evaluation. Experimental 1. For each wavelength to be tested, prepare five standard solutions; the lowest should have a concentration correspond- ing to about one order of magnitude above the detection limit.The other four should be prepared at intervals of about an order of magnitude so that a total of 5 orders of magnitude is covered. Preparation of such a series of solutions is facilitated by the use of a suitable automatic diluter. 2. The instrument should be set up to examine the appro- priate analytical lines and the above solutions should be aspirated in turn with a blank between each solution. This would conveniently be carried out using an automatic sample changer. The data system should be set to record the blank ( b ) , the total signal (x) and the next signal (x - b). The values of xlb should also be computed and stored. N.B. Prior to commencing a series of measurements it is essential to ensure that the sample introduction system has reached a steady state.3. Measure the second solution in each series 30 times over a period of 1 h, then increase the instrument gain by a factor of two and repeat the measurements. 4. Resolution should be checked at several points in the spectrum by recording the spectrum of suitable elements with closely spaced lines. Suitable sets of lines include the following (in nm). Reason Availability of efficient programme and good documentation can greatly reduce commissioning time for a new instrument. Simple instruments are often good value for money, whereas those with many refinements are often costly. 208.893 208.959 Boron { Score PS WF ST Sum of Sub- totals PS WF ST Grand Total r 309.997 334.884 i310.067 334.941 Iron 310.030 Titanium 237 31 249.773 313.155 Mercury { 313.183 Aluminium { 237:34 Beryllium Boron { 249.678 Germanium { 265.12 265.16 Titanium { i;;:;: Aluminium { 257.41 257.44 Sodium { i;::;; Aluminium { 371.592 371.645 Iron { 371.841 371.994 Iron { 372.256 372.438 390.648 390.794 Iron { Iron { 522.430 522.493 Titanium { Treatment of Results The first set of results should be used to establish the calibration function, (x - b) versus concentration.This will permit a check on the linear dynamic range of the instrument. Statistical examination of the residuals will give additional information on the efficiency of the curve fitting programme. Data should not be presented or analysed in the form of log - log graphs, as large differences in signal show only as small shifts in the graphs.Individual points can be compared by calculating the standard deviation of the residuals of the replicates, while if desired the total plot of each set of data can FJ t I R' D Concentration Fig. 1. Graph of relative standard deviation ( x - b ) versus concentration (log xlb)ANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 9 be compared by means of multi-tailed "F-test" (or analysis of co-variance) using the residuals. Short-term precision should be evaluated by calculating the standard deviation of ( x - b) for the second set of results. The mean of ( x - b) for each set will give a measure of the accuracy i f compared with the computed value from the first set of results. A plot of RSD versus log xlb will provide a graph from which the analytical range and the detection limit can be computed. The detection limit (D, 20) is, by definition, the point at which the RSD of x - b = 50% and i s accepted for the purposes of this document.However, the actual definition is unimportant, provided that i t i s consistently applied. The analytical range R' - R i s the range over which the function has values of less than, for instance, three times the minimum value, rn. These values can be expressed in terms of log xlb, which i s directly related to concentration. The lower the value of D and rn and the greater the value of R' - R, the better the performance of the instrument. GORDON F. KIRKBRIGHT BURSARY FUND This fund was established in 1985 as a memorial to Gordon Kirkbright and his contributions to analytical spectroscopy and analytical science in general.The aim is to enable promising young analytical scientists of any nation to visit a recognised scientific meeting or place of learning in order to further their education. Applications are invited for the Award of the Gordon F. Kirkbright Bursary While there are no formal age restrictions on the award it is expected that the successful applicant will either be undertaking research towards a PhD or be in his or her first postdoctoral position. Please write for an application form to Dr. N. W. Barnett (Vice-chairman of the Association of British Spectroscopists), Department of Environmental Sciences, Plymouth Polytechnic, Plymouth, Devon PL4 8AA. The form must be completed and returned to the above address not later than March 31st, 1987. RSC ELECTROANALYTICAL GROUP 6th International Symposium on Electroanalysis and Sensors in Biomedical, Environmental and Industrial Sciences UWIST, Cardiff, April 69,1987 The Plenary and Keynote Lectures to be presented at this Symposium will include the following: A. G. Fogg (Loughborough, UK), "Electrochemical Pre-treatment and Chemical Modification of Electrodes"; G. G. Guilbault (New Orleans, USA) "Enzymes and Biosensors"; W. R. Heineman (Cincinnati, USA), f'lmmunoassay with Electrochemical Detection"; J. Janata (Utah, USA) "Integrated Solid-state Electrochemical Sensors"; H. J. Marsoner (Graz, Austria), "Quality Control and Standardisation for ISE Analysis in Clinical Practice"; C. Tran Minh (St. Etienne, France), "Biosensors for Electrochemical Analysis of Enzyme Inhibitors"; M. Otto (Freiberg, GDR), "Chemometric Principles in Electrochemical Analysis"; E. Pungor (Budapest, Hungary), "Education and Training of Non-chemist Users of Electrochemical Sensors"; and J. Wang (New Mexico, USA) "Recent Advances in Adsorptive Stripping Voltammetry". Contributed papers will be presented as lectures or posters. Some additional contributions may be accommodated. There will be an exhibition of commercial equipment. Further information and registration details can be obtained from the Short Courses Section (Electroanalysis Symposium), UWIST, P.O. Box 68, Cardiff CF1 3XA. Tel. (0222) 42588, Ex. 2213.

ISSN:0144-557X    

DOI:10.1039/AP9872400003

出版商:RSC    

年代:1987

数据来源: RSC

摘要:

10 ANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 Inductively Coupled Plasma - Mass Spectrometry ~~~ ~ The following are summaries of three of the papers presented at a Joint Meeting of the Microchemical Methods and Atomic Spectroscopy Groups held on March 6th, 1986, at the Geological Society, Burlington House, London, W.1. Inductively Coupled Plasma - Mass Spectrometry: The Manufacturer's View J. E. Cantle VG Isotopes Ltd., Ion Path, Road Three, Winsford, Cheshire CW7 3BX Of inductively coupled plasma - mass spectrometry (ICP - MS) it has often been asked-is it a mass spectrometer with a novel and extremely powerful atmospheric ion source or is it really an ICP with an alternative type of detector? Clearly both views have merit. For VG Isotopes (the inorganic mass spectrometer division of the VG Instruments Group) the PlasmaQuad was our first ICP product, although entering this field did not prove to be a problem: ICP technology is widely available and very quickly we were able to design and build our own ICP torch box and gas control system, including mass flow controllers. We therefore quickly came to terms with the ICP part of the technique.The MS part was even more straightforward. VG Instruments supplies more mass spectrometers (total value) world wide than any other supplier, the vast majority of instruments being for organic molecular analysis. The in- organic side of MS is small, even more so since the non- commercial availability of the spark-source MS. We had been aware of Alan Gray's work at the University of Surrey since the late 1970s, in fact our first quotation to supply part of what can be considered to be the pre-production prototype was prepared in 1978.During the early days ICP - MS was regarded as something of an academic curiosity. Its early characteristics were fast solution sample processing, good limits of detection similar (then) to optical emission ICP, and mass spectra that were cleaner than optical spectra and which contained potentially valuable isotopic information. During 1982, however, limits of detection improved dramatically, and it was at that point that those concerned with trace element analysis took note. ICP - MS could no longer be ignored. In considering the introduction of a new analytical instru- ment a manufacturer looks for a good size market and minimal risk.ICP - MS offered the potential of using well proved components, for example, the ICP and the quadrupole mass filter. VG was, therefore, ideally placed. The Model VG1212 quadrupole was immediately available, having been already extensively field tested in other areas of application, notably GC - MS. So, with the launch of the PlasmaQuad, in May 1983, we had the basis for: making a considerable contribution to analytical science; providing jobs for UK scientists and engineers; and keeping VG shareholders happy. It is fair to say that all of these potentialities have been and are still being realised. A separate division has been created to concentrate on this product and now occupies a 26000 ft2 purpose built factory. A total of 35-40 systems have been, or are in the process of being, installed in user laboratories throughout the world.The current capabilities of the instruments are summarised as follows: wide range of elements determined with sub ng ml-1 limits of detection; automatic operation; multi-element capa- bility; high dynamic range with linearity over six orders of magnitude; minimal matrix effects; fast sample throughput- typically a few minutes; direct analysis of solutions; simple spectra, unambiguous data; rapid isotope ratio determination; and isotope dilution capability for high accuracy deter- minations. Trace Element Analysis by Inductively Coupled Plasma - Mass Spectrometry J. E. Fulford SCIEX, 55 Glen Cameron Road, Thornhill, Ontario, Canada L3T 1P2 B. C. Gale Bristol Industrial and Research Associates Ltd., P.O.Box 2, 6 Combe Road, Portishead, Bristol BS20 9JB Three years of experience with inductively coupled plasma - mass spectrometry (ICP - MS) have indicated that there are certain limitations to attaining good analytical performance with “real-world’’ samples. However, as these problems have been encountered, instrumental developments have been initiated to overcome them. Routine analysis with any system requires that the set-up conditions should be reproducible from sample to sample, and that the analytical figures of merit (detection limits, precision, long-term stability and sample throughput) can be met. In this paper we present the system characteristics which make ICP - MS a routine method for many different samples, and further, illustrate the analytical figures of merit with analytical results from certified “real-world’’ samples.Experimental The instrument used for this work is the SCIEX Elan 250 ICP - MS System.1ANALYTICAL PROCEEDINGS. JANUARY 1987, VOL 24 11 Sample solutions were prepared with Ultrex acid digestions and distilled, de-ionised water was used for sample dissolution and dilution. Results and Discussion In ICP - MS ions from the ICP are extracted and focused into a quadrupole mass filter by electrostatic ion optics. The focusing properties of these ion optics are strongly dependent on the ion kinetic energy as the ions emerge from the plasma. If a secondary discharge exists between the plasma and the interface, the ion energy varies strongly with small changes in aerosol flow-rate ,2 forward power and sample composition3; thus, for the optimum performance with this type of system, ion optical adjustment is required if the plasma conditions or samples change. At the same time as these focusing conditions change, the production of doubly charged and oxide species can change dramatically, depending on plasma parameters. With the system used in this study the plasma nominally operates at the same electrical potential as the sampling interfaced and the plasma characteristics are not interactive with the ion optics.This is illustrated in Fig. 1, wherein the ion energies are seen to vary by less than 1 V over a large range of 12 1 I - E 4' LI - I I 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 Aerosol flow-rate I min Fig. 1. Dependence of ion energy on aerosol flow-rate aerosol flow-rates. In this system a single ion optical setting is required for most plasma conditions and yields the same relative levels of doubly charged and oxide species over a broad range of plasma running conditions, which are appropriate for good analytical performance.(The mass dependence of ion energy indicated in Fig. 1 is in agreement with theoretical expectation of the molecular beam sampling technique . 5 ) The freedom from interactive effects offered by control of the plasma potential makes the routine of set up and sample analysis a very simple and fast process. Table 1. Feldspar FK-N Association Nationale de la Recherche Technique (ANRT) standard ICP - MS Reference methodipg g- 1 value Be P Cr Mn c o Ni c u Zn As Sr Cd Sn Sb Ba T1 Pb Bi 1.71 k 0.C35 257 k 14 2.05 k 0.043 26.3 t 0.51 18.0 t 0.36 1.77 t 0.088 1.99 k 0.030 10.2 k 0.23 1.99 t 0.08 39.8 & 0.79 0.057 f.0.006 2.00 t 0.018 0.708 & 0.008 206 t 8.5 4.38 k 0.19 282 t 2.7 0.089 t 0.007 1 105 5 39 16 3 2 10 39 - 0.02 0.5 200 240 - For samples of geological interest, Table 1 shows results from a rock digested by hydrofluoric acid analysed at the equivalent of 1% mlVsolutions in 2.5% nitric acid with a trace of hydrochloric acid. The results show reasonable accuracy to below 1 p.p.m. in the solid, demonstrating the detection capability. This sample was run as one of 10 similar samples of soil and rock, which were analysed in 40 min including washout times. The precision of the measurements shown in Table 1 shows that 2% precision is achievable at levels of 10 p.p.m.in the solid. Interferences for P(HN0) as As (ArCl) are evident and uncorrected in these results. An example of analysis in a biological matrix is shown in Table 2, for bovine liver. The sample was ashed and run as 0.1% mlV in 0.5% perchloric acid, and the results, which are not corrected for molecular ion interference, show excellent agreement with the certified values and detection limits well below 1 p.p.m. in the original solid. Table 2. NBS SRM 1577a: bovine liver Element and Average of 3 samples Certified values isotope measured (pg g-1 or mass Yo) (pg g- 1 or mass %) 23Na 14Mg 3'P 34s 3yK MCa 55Mn s7Fe 6"u 0.217 k 0.007 624 k 2 1.18 k 0.005 0.79 k 0.02 0.894 & 0.03 145 t 3 9.1 k 0.08 202 k 2 160 * 0.6 0.243 k 0.013 600 t 15 1.11 t 0.04 0.78 & 0.01 0.996 t 0.007 120 k 7 9.9 k 0.8 194 k 20 158 _+ 7 The results for coal fly ash (shown in Table 3) show good long-term stability as the precision of the system over the 2-h period was only slightly higher than the short-term precision Routine analysis of materials with highly refractory oxides can cause instrument drift as a result of blockage of the orifices in the interface.The blockage is such that the effect on all species occurs to the same degree, thus internal standardisation can be used for reliable quantification. This is illustrated by Fig. 2, where Mn has been used as the internal standard for several elements in 0.2% A1203. The internally standardised (1-2%). Table 3. NBS SRM 1633a: coal fly ash. Seventeen repeats in 1 h 52 min; 1 p.p.m.in internal standard Average measured Element and concentration Actual concentra- isotope in original R.s.d. of tion in original measured solution, p.p.b. 17 repeats solution, p.p.b. 75As 370 3.2% 362.5 "Mo 73 2.1% 72.5 60Ni 330 2.7% 318 208pb 176 1.7% 181 l2lSb 17.2 4.1% 17.5 78Se 29.8 40% 25.8 120Sn 9.9 3 .O% 9.8 205T1 14.3 4.2% 14.25 'Be* 33.6 1 2 O/O 30 S2Cr 525 3.6% 490 63Cu 307 3.6% 295 55Mn 516 3.5% 475 51Vt 810 5.1 Y" 750 WZn 576 3.3% 5.50 232Th 58 3.5% 61.8 235u 25.6 0.23% 25.5 * Poor r.s.d. caused by background from unresolved shoulder of Poor accuracy and r.s.d. due to background horn 35C1160 from intense 1°B peak present due to boric acid in sample. HCI in sample.12 ANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 o.8 t 0 50 100 150 200 250 Ti me/m in Fig.2. standardisation. A, Cobalt; B, copper; and C, titanium Signal stability for trace elements in 0.2% A1,03 using internal results are stable over several hours to within 5% and the detection limits in the sample deteriorate by less than 10% as a result of the orifice blockage. Conclusion The analytical “figures of merit” for trace elemental analysis using ICP - MS show that the technique has come of age and has good accuracy, precision and long-term stability for even the most difficult samples. This analytical performance, combined with the ease of daily routine set-up provided by careful interface design, makes ICP - MS worthy of serious consideration in most routine applications. References “Elan 250 ICP - MS,” SCIEX, Thornhill, Ontario, Canada.Gray, A. L., Spectrochim. Acta, Part B , 1986, 41, 151. Houk, R. S., Pittsburgh Conference, 1986, Paper 002. Douglas, D. J . , and French, J . B., Spectrochim. Acta, Part B , 1986, 41, 197. Fulford, J . E., and Douglas, D. J., Appl. Spectrosc., in the press. 1. 2. 3 . 4. 5 . A User’s View of Inductively Coupled Plasma - Mass Spectrometry in Routine Analysis P. Allenby Technical Department, British Nuclear Fuels plc, Spring fields Works, Salwick, Preston, Lancashire PR4 OXJ The determination of trace metal impurities in uranic materials by emission spectrographic techniques has always been limited by the complex nature of the uranium spectrum. Lengthy chemical procedures, to separate the impurities from the uranium, or methods based on reducing the volatility of the uranium, the so-called “carrier distillation” technique, are necessary for such analysis.The introduction of atomic-absorption spectrophotometers made possible the direct determination of the lighter, less refractory, elements in uranic solutions. However, a consider- able number of elements remain, where the classical emission techniques are still the only methods capable of achieving the detection limits required. As inductively coupled plasma mass spectrometry (ICP - MS) does not suffer from spectral limitations we decided to evaluate the technique for our applications. Currently, we are assessing a Vacuum Generators (VG) PlasmaQuad for use in the determination of trace metallic impurities in a range of uranic materials.Our work has been directed initially at those elements not readily amenable to analysis by atomic absorption. The elements of prime interest are shown in Table 1 and are divided into three groups, dependent on the required determination range. Table 1. Elements determined in uranic materials Determination rangeipg g-’ of 1-10 Group uranium Elements A B C Li, Be, Co, Ga, Ge, As, Sr, Cd, In, Sn, Ba, T1, Pb, Bi Ti, V, Zr, Nb, Mo, Ru, Sb, Hf, Ta, W La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Th 0.1-1 0.005-0.1 Many uranic materials that we analyse contain high concen- trations of fluoride and in some instances fluoride has to be added to solutions to prevent hydrolysis of the impurities in the uranic matrix. In order to accommodate these high fluoride concentrations and other corrosive matrices sometimes encountered, we required an inert nebuliser and spray cham- ber for our work.Nebuliser System An inert nebuliser system was supplied with the PlasmaQuad and was found to be unsuitable for our work, giving poor drainage and high memory values. A smaller chamber was manufactured, to our specification, and designed so that different commercial nebulisers could be fitted. After trials we chose the Jarrel Ash fixed crossflow nebuliser for our work. With the smaller chamber a different torch box arrangement was possible, the nebuliser now inclined at 45”, which gave better drainage. In addition, we connected the drain to a peristaltic pump so that it could be continuously purged. This nebuliser has proved to be very successful, giving detection limits comparable to other systems.Its compact size and orientation have contributed to its good thermal stability, drainage and low memory effects. The chamber and nebuliser have been in use for 12 months now with no evidence of attack or wear. Solutions containing up to 2% of fluoride have been sprayed, in addition to phosphoric and sulphuric acids and various fusion mixtures. Analytical Work After initial work, we estabished that a uranic solution containing 4 g 1-l of uranium could be tolerated by both the nebuliser system and the ICP interface. The main acid matrix was nitric acid with or without the inclusion of fluoride or hydrofluoric acid, depending on the elements and materials under investigation.ANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 13 Detection limits for the elements in our Groups B and C for various matrices are shown in Tables 2 and 3, the nebuliser configuration and conditions for all this work being given in Table 4.Table 2. Detection limits (2s) for group B Matrix Non-uranic, 1 YO HN03 Element and isotope Ti-48 Zr-90 V-5 1 MO-95 RU-102 Sb-121 Hf-178 Ta-181 V-184 ng ml-1 0.21 0.12 0.02 0.08 0.04 0.04 0.08 0.03 0.08 Uranic 4 g 1-1, 1% HN03 and 2 g 1-1 HF !% 8Y1 of ng ml-1 uranium 0.23 0.06 0.09 0.02 0.11 0.005 0.13 0.03 0.05 0.01 0.08 0.02 0.04 0.01 0.03 0.01 0.06 0.015 Table 3. Detection limits (2s) for group C Matrix Non-uranic, 1% HN03 Uranic 4 g 1-1, 1 % HN03 and 2 g 1- 1HF Element and isotope La- 139 Ce-140 Pr-141 Sm-149 Nd-146 EU-151 Gd-158 Tb-159 Dy-163 HO-165 Er-166 Tm-169 Yb-174 LU- 175 Th-232 ng ml-1 0.09 0.03 0.05 0.13 0.13 0.06 0.03 0.04 0.12 0.03 0.09 0.03 0.07 0.03 0.03 ng ml- * 0.16 0.08 0.07 0.28 0.37 0.11 0.19 0.05 0.18 0.06 0.14 0.05 0.13 0.04 0.09 I% s:' of uranium 0.04 0.02 0.02 0.07 0.09 0.03 0.05 0.01 0.045 0.015 0.035 0.01 0.03 0.01 0.02 This work showed that a direct solution technique could produce detection limits for our Group B elements within the required determination range, but a concentration stage was necessary for our Group C elements. Stability and Precision The long-term stability of the system was checked by continu- ously spraying a solution containing the Group B impurities and collecting data over a period of 60 min.A drift of approximately 10-20Y0 was found, which was mass dependent.In order to compensate for this effect and improve the precision an internal standard was proposed. Tests were carried out using praseodymium-141 as the internal standard for our Group B elements. A series of solutions was prepared containing 0, 1, 10 and 50 pg g-1 of Table 4. Conditions for the analysis Nebuliser Jarrel Ash, fixed crossflow Chamber PTFE, BNFL design Torch 2 piece quartz Sample uptake 1.20 ml min-' Drain pump rate 2.40 ml min-l 0'7 mm} Pure uncoated nickel Sampling cone Skimmer cone l.Omm uranium of all of the elements. Each solution contained 4 g of uranium, 2 g of hydrogen fluoride and 100 yg of praseody- mium-141 per litre in nitric acid (1 + 99). Statistical data were obtained for the 1 and 10 pg g-1 of uranium solutions using the 0 and 50 yg g-1 solution for calibration; the mean results of 10 runs are shown in Table 5.Table 5. Statistical data for determination of trace elements in uranium solutions Nominal value 10 pg g-1 of 1 CLg s;' of uranium uranium Element Titanium Vanadium Zirconium Niobium Molybdenum Ruthenium Antimony Hafnium Tantalum Tungsten Mead 0.97 1.07 1.06 1.06 1.05 1.14 1.10 1.09 1.04 1.06 v g g-l S.d. (Is)/ 0.18 0.14 0.10 0.05 0.21 0.14 0.07 0.03 0.05 0.05 PLg g-l Mean/ 9.82 9.90 9.91 10.02 9.68 10.09 9.91 9.82 9.87 9.83 g-' S.d. (Is)/ 0.51 0.41 0.25 0.34 0.65 0.34 0.32 0.25 0.19 0.34 g-l Further work has been initiated on an extraction procedure using tributyl phosphate as the extractant for our Group C elements. This work has shown that for a sample mass of 5 g of uranium, two extractions with tributyl phosphate using odour- less kerosene as diluent will remove sufficient uranium to yield a final solution containing less than 0.2 g per 100 ml of uranium. Work is in hand to determine the over-all precision and accuracy of this procedure. Conclusion Our initial work on the PlasmaQuad has been encouraging and has shown it to have considerable potential for our applica- tions, but the long-term reliability of the instrument has to be proved. 1987 PITTSBURGH CONFERENCE Once again, the RSC is organising a tour group for Members of the Society attending the Pittsburgh Conference. Travel will be with TLYA from London Heathrow to Kennedy, New York, and will include coach transfer to Atlantic City and accommodation on a room-only basis in selected hotels close to the Convention Centre. Additional requirements such as transfer to Heathrow and personal onward itineraries after the meeting can be catered for, as well as car hire, assistance with visas, etc. The pressure on hotel space in Atlantic City is enormous, as any visitor to previous Pittsburgh Conferences will testify. Our rooms are already reserved, so booking with the RSC Group is your guarantee of good accommodation and a trouble-free meeting. For further details, telephone Karen AMizel on 01 437 8656, extension 250.

ISSN:0144-557X    

DOI:10.1039/AP9872400010

出版商:RSC    

年代:1987

数据来源: RSC

摘要:

14 ANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 Annual Chemical Congress: New Spectroscopic Sensors and Techniques The following are summaries of five of the papers presented at the Analytical Symposium of the RSC‘s Annual Chemical Congress, held on April 8th-llth, 1986, in the University of Warwick, Coventry. The Theophilus Redwood Lecture, delivered at the same meeting by Professor G. M. Hieftje, was published in the November, 1986, issue, p. 382. Fibre-optic Probes for Chemical Sensing Otto S. Wolfbeis Institute of Organic Chemistry, Karl-Franzens-University, 80 I0 Graz, Austria A sensor is a device that is capable of reporting continuously and reversibly the concentration of an analyte or a physical parameter. There is considerable interest in sensors by virtue of the real-time nature of most sensors, the increasing concern about environmental quality and, in a more and more cost-conscious world, their considerable personnel savings in comparison with manual off-line methods.Optical sensors have a few advantages over the widely used electro-chemical sensors: firstly, they do not require a refer- ence signal, as is necessary in all potentiometric sensing methods; secondly, because the primary signal is optical it is not subject to electrical interferences by, for example, static electricity or surface potentials; thirdly, low-loss optical fibres allow transmittance of optical signals over long distances, typically 2-100 m, thus facilitating remote sensing, for instance in ultra-clean rooms, when samples are hard to reach, dangerous, too hot or too cold, or radioactive; and fourthly, fibre optic sensors lend themselves to miniaturisation.Typical inner diameters of fibre ends are in the 100-500-pm range, a fact that makes them most useful for invasive sensing. Notwithstanding these advantages, one should note the following disadvantages: ambient light interferes in many instances, and it is therefore necessary to prevent light from entering the fibre, or to encode the optical signal so that it can be discerned from background light; photobleaching and wash-out of immobilised indicators gives rise to a limited long-term stability and to signal drifts; and sensors with immobilised indicators have limited dynamic ranges because the respective equilibria obey the mass action law rather than the Nernst relationship.Plots of signal versus the log of analyte concentration are therefore S-shaped rather than linear. Plain Fibre Sensors In the simplest version, a fibre sensor consists of a light guide that transports light from the source to the sample. The sample absorbs or reflects part of the light or emits fluorescence of a different wavelength. Transmitted, or reflected, or emitted light is collected by the same fibre, or another one, and guided back to an optical system that detects its intensity. This kind of sensor is frequently referred to as a “plain fibre sensor.” It makes use of the intrinsic colour or fluorescence of an analyte, but, in fact, this kind of “sensor” is nothing other than a device for performing classical photometric analysis outside the pho- tometer.Because of the ruggedness and inertness of plastic fibres, the plain fibre technique can be exploited to solve unusual problems. Hieftje and co-workers, for instance, utilised the 820 nm absorption of copper(I1) ions in dilute sulphuric acid in order to monitor their concentration in an electroplating bath. In a similar fashion, the uranyl ion has been detected in groundwater using fibres that transmit excitation light to the sample and guide back its fluorescence to a detector.2 Plain fibre detectors are very simple, cheap and display good long-term stability. On the other hand, they are not very selective. Plastic fibres can also be applied to monitor the course of titrations (such as the argentimetric halide determination), the end-point of which can be indicated optically.3 The advantage of the fibre-optic method is that it can easily be automated, and that the end-point determination is operator-independent .Indicator Phase Sensors Plain fibre sensors cannot be used to detect non-absorbing species such as hydrogen ions and most gases. It has therefore become necessary to immobilise suitable indicators on solid supports. In contact with the analyte, the colour of the indicator phase is a measure of the concentration. The sensing layer is frequently attached to the end of a fibre optic. These arrangements are referred to as “reagent phase sensors.” A few representive examples are given below. pH Sensors A typical representative is provided by the optical pH sensor developed by Peterson et al.4 The working principle is based on the measurement of spectral changes of phenol red with pH.Light from a tungsten lamp is directed via the input fibre on to dyed polymer particles. The dye is chemically bonded to polyacrylamide microspheres. The material is kept in position at the fibre end by cellulose tubing. Reflected light enters a second fibre and passes two optical filters that isolate two analytical wavelengths. One of these is adjusted to the maximum spectral change of the indicator with pH, whereas the other is used as a reference signal that accounts for fluctuations in light source intensity, bleaching and other variables. The sensor measures pH over the physiological range to the nearest 0.01 pH unit, but has a fairly slow response. Fluorescent pH sensing membranes have much shorter response times than absorbance-based sensors, typically 30 s.This is because of the great sensitivity of fluorescence, a fact that allows the fabrication of extremely thin membranes, which are quickly penetrated by protons. A disadvantage of all optical pH sensors is their sensitivity towards changes in ionic strength. This is in striking contrast toANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 electrodes, where a true potential is measured. Interferences resulting from changes in ionic strength are, at present, a limiting factor, and various attempts have been made to circumvent the problem, but none of these is simple enough for routine instrumentation. Oxygen Sensors Oxygen is usually detected with fluorosensors that rely on the dynamic quenching of the fluorescence of suitable indica- tors.5.6 A fibre optic based instrument for the continuous monitoring of pH, oxygen and carbon dioxide in blood has been developed by the CDI Corporation (in 1984).All three parameters are measured by fluorescence techniques, using appropriate sensing layers attached to the ends of the fibres, which are in contact with blood that circulates in an extra- corporeal loop. Electrolyte Sensors Various principles have been applied to probe metal ions. Absorbance-based sensors are rather rare because most of the ions of interest are not coloured. Table 1 summarises the current state of the art. Table 1. Optosensors for electrolytes Species Sensing principle Alkali ions Al( III), Be( 11) Mg(II), Al(II1) Cu(I1) UOz(I1) Pu( 111) C1.Br, I Sulphide Competitive binding between Na and a fluorescent dye for Cu(1I) - polyethyleneimine Spectral changes of fluorescent crown ethers in PVC Fluorescence of imrnobilised morin Fluorescence of immobilised Static quenching of fluorescence Absorbance at 820 nm Native fluorescence at 570 nrn Dynamic quenching of the Tb(II1) fluorescence Quenching of the fluorescence of glass-immobilised quinoline Quenching of the fluorescence of immobilised acridinium oxine-5-sulphonate of immobilised indole Reference 10 11 12,13 14 15 1 2 16 17 18 ~~ Current Trends Optical effects other than absorbance or fluorescence may, of course, also be exploited. These include refractometry, ellip- sometry and Raman scatter. A very promising detection principle relies on evanescent wave spectrometry, which may experience its greatest success in studies on interface phenomena such as antigen - antibody binding processes, when one of the reaction partners is immobilised.7 There are three significant trends recognisable in the development of chemical sensors at present.The first trend 15 involves measurement of parameters other than simple light intensity, for instance polarisation and fluorescence lifetime. The latter technique has a few decisive advantages over the former technique, which include inertness to leaching, bleach- ing and stray light, and an absolutely linear calibration plot. The second trend is to a multiple sensor. A sensor has been developed for in vivo measurement of pH, oxygen, carbon dioxide and temperature.8 It consists of three single fibres, each covered with the analyte-sensitive material at the distal end.The sensor, covered with a black coat to prevent other fluorescent compounds interfering, is about 1 mm thick. In order to achieve long-term stability, all sensors work at two analytical wavelengths, one of which serves as a reference signal and the other as the analytical signal. A third trend at present is to find a more general concept for metal ion sensing, as a more general approach is needed. Currently, thin layers of a polymer, or long-chain fatty acid films of the Langmuir - Blodgett type, with an ion carrier such as valinomycin together with a potential-sensitive dye incor- porated into the membrane, are under investigation for their suitability as “general purpose” electrolyte sensors.9 The advantage of this sort of sensor is that a number of electrolyte sensors could be fabricated almost identically, differing only in the nature of the carrier.1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. References Freeman, J. E., Childers, A. G . , Steele, A. W., and Hieftje, G. M., Anal. Chim. Acta, 1985, 177, 121. Malstrom, R . A . , and Hirschfeld, T., Anal. Chern. Symp. Ser., 1984, 19, 25. Wolfbeis, 0. S., and Hochrnuth, P., Mikrochirn. Acta, 1984, 129. Peterson, J. I . , Goldsteein, S. R., Fitzgerald, R. V., and Buckhold, D. K., Anal. Chern., 1980, 52, 864. Bergman, I . , Nature (London), 1968, 218. Peterson, J. I., Fitzgerald, R . V., and Buckhold, D. K., Anal. Chern., 1984, 56, 62. Place, J.F., Sutherland, R. M., and Dahne, C., Biosensors, 1985, 1, 321. Gehrich, J. L., Lubbers, D. W., Opitz, N., Hansmann, D. R., Miller, W. W., Tusa, J. K . , and Yafuso, M., IEEE Trans. Biomed. Eng., 1986, 33, 117. Wolfbeis, 0. S . , and Schaffar, B. P., Anal. Chim. Acta, submitted for publication. Zhujun, Z . , Mullin, J. L., and Seitz, W. R . , Anal. Chirn. Acta, 1986, 184. 251. Wolfbeis, 0. S . , and Schaffar, B. P . , 1986, unpublished work. Saari, L. A . , and Seitz, W. R., Anal. Chern., 1983, 55, 667 Sarri, L. A , , and Seitz, W. R., Analyst, 1983, 109, 655. Zhujun, Z . , and Seitz, W. R., Anal. Chirn. Acta, 1985, 171, 251. Wolfbeis, 0. S . , 1985, unpublished work. Hirschfeld, T., “Remote Analysis Using Fiber Optics,” Paper presented at the Thirteenth Congress of the International Commission for Optics, Sapporo, Japan, August 20-24, 1984.Urbano, E., Offenbacher, H., and Wolfbeis, 0. S . , Anal. Chem., 1984, 58, 427. Trettnak, W., Diplomarbeit, University of Graz, 1986. Waveguide lmmunoassays A. M. Smith Unilever Research, Sharnbrook, Bedford MK44 7 LQ Antibodies and immunology are used widely for the detection of analytes in body fluid samples. The test methods used usually require sophisticated instrumentation and/or trained staff in clinical laboratories, so that only in particular circum- stances. usually where a simple yesino answer is required, are tests using antibodies available to the non-specialist user, the most obvious example being the home use pregnancy test. There is, therefore, considerable interest in tests that can be performed by non-specialist staff in hospital clinics or the doctor’s surgery and where results are available in minutes16 ANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 rather than hours.Some tests are available for this expanding market but very few employ immunology. This paper describes potential optical methods that could find application in easy to use and rapid immunosensors. Work by various groups worldwide is summarised and a specific optical immunosensor, which is under development within Unilever, is outlined. Optical Principles There are a number of different immunoassay methods in use, but most require precise measurement of a volume of sample and one or more reagents, a period of waiting while the reaction reaches equilibrium and a separation step in which excess reagent is removed before a measurement is taken, Various optical methods have been suggested in order to remove the need for a separation step.In each instance, antibodies are immobilised on a solid phase, which is an optical material, and modifications to the optical properties of the system are measured. A fundamental principle which may be used is modification of the total internal reflection properties of an optical prism as a result of changes in the layers of material close to or attached to the totally internally reflecting surface. This is a well known spectroscopic method1 and makes use of the fact that the incident and reflected light waves set up a standing wave pattern around the interface, which decays exponentially (evanescent field) into the surface layer on the optical material.Any absorbing species within the evanescent field, which extends for a distance of about one wavelength from the interface, will result in a change in the measured reflectivity. Similarly, if a fluorescent species is close to the surface it may absorb light and some of the fluorescent re-emission will be relaunched into the optical substrate. In this way the presence of a fluorescently labelled molecule near the interface can be detected either by a decrease in the reflected pump light or by an increase in the fluorescence emission. A further adaptation of the total internal reflection concept uses a thin film of silver, about 50-nm thick, on top of the optical substrate. For a particular total internal reflection angle it is possible to excite a surface electron wave mode of the interface between the metal and the sample.This phenomenon is known as surface plasmon resonance2 and, as the plasmon is lossy, it results in a sharp dip in the reflectivity at one particular angle. The angle or wavelength at which the dip occurs depends critically on the properties of the surface layer on top of the metal film and therefore can be used to monitor changes in lhe surface layer caused by, for example, antibody - antigen binding. Optical Separation Methods It was recognised that total internal reflection spectroscopy could be used to study antibody - antigen binding.3 The sensitivity of the method was, however, limited and later attempts have concentrated on using geometries where mul- tiple total internal reflections occur, such as optical fibres and waveguides, or on using fluorescently labelled molecules.Fibre based systems have been proposed46 where an antibody is immobilised on the outer surface of an exposed fibre core. Sample antigen and fluorescently labelled antigen conjugate are then allowed to compete for the limited number of binding sites. The fluorophor is pumped evanescently through the fibre and the re-launched fluorescence is measured in order to monitor the binding. This concept is very attractive because it represents a single-ended “dipstick” sensor that can simply be inserted in a tube of pre-mixed sample and reagent. A similar approach uses multiple reflection in a slab of silica in order to monitor binding.7 In addition to making measurements of the signal from a fluorescent reagent,8 changes in the scattered light levels accompanying binding have also been observed.9 Sensitivities of around 10 nM have been achieved.The ability to carry out an assay without having to use a labelled reagent is very attractive and has spurred efforts to look at direct methods for detecting changes in surface layers. The surface plasmon resonance phenomenon yields an evanes- cent field, which is more intense than the equivalent total internal reflection disturbance. Relatively large changes in the resonance angle have been observed when successive layers of IgG and anti-IgG molecules are laid dQwn on a silver layer.lo%ll More recently, it has also been suggested that metal films on very fine grating structures could be used more conveniently than their flat-film counterparts, 12 All sensing methods which do not use labels, however, suffer from the disadvantage that the change in signal is dependent primarily on the mass of material deposited. For a large relative molecular mass protein this is no problem, but for low relative molecular mass materials, such as therapeutic drugs or hormones, it is difficult to achieve the sensitivities needed for practical assays.Fluorescence Capillary Fill Device The work being carried out at Unilever on optical separation technology has led to a new assay format, which incorporates a rectangular optical waveguide and uses a fluorescently labelled conjugate reagent. 13 The format is known as the fluorescence capillary fill device and relies on many aspects of liquid crystal display technology for its manufacture.The device consists of two plates of glass separated by a narrow, precisely defined gap of about 0.1 mm. The lower plate of the cell, which acts as an optical waveguide, has a dried layer of immobilised antibody and the upper plate has a pre-dosed dried fluorescent conjugate reagent. A drop of sample is presented at one end of the narrow cell gap and is drawn in by capillary action. The reagent dissolves in the sample and the labelled and unlabelled antigen molecules compete for the limited number of binding sites on the waveguide. After the assay has reached comple- tion, which can be a matter of minutes, the fluorescent molecules are excited by an external light source and the fluorescence emission from the end of the lower plate is used to measure the amount of binding.Angular discrimination is used to separate light coming from bound antigen molecules from the light emitted by conjugate still in solution. The potential advantages of this approach are that in addition to the incorporation of an optical separation step, the need for precise metering of sample and reagent is eliminated and a fast result is possible. In addition, the instrument required to “read” the device is of low cost and many of the required manufacturing methods are already established within the electronics industry. Conclusions Optical separation methods offer considerable potential for simplifying immunoassay procedures and bringing them closer to the doctor’s office.The successful format must, however, be able to offer ease of sample handling, a fast result and also low cost manufacture. References 1. Harrick, N. J . , “Internal Reflection Spectroscopy,” Harrick 2. Agranovich, V. M., and Mills, D. L., “Surface Polaritons,” 3. Kronig, M. N., and Little, W. A . , Bull. Am. Phys. Soc., 1973, 4. US Pat., 4050895, 1976. 5 . Eur. Pat., 0103426, 1982. 6. Andrade, J . D., van Wagenen, R. A.. Gregonis, D. E., Newby, K., and Lin, J. N., IEEE Trans. Electron. Dev., 1985, ED-32, 1175. Scientific Corporation, 1979. North Holland, Amsterdam, 1982. 18, 782. 7. Eur. Pat., 0075353, 1981. 8. Sutherland, R . M., Dahne, C., Place, J . F., and Ringrose, A. S . , Clin. Chern., 1984, 30, 1533.9. Sutherland, R. M., Dahne, C., and Place, J . F . , Anal. Leu., 1984, 17(B1), 43.ANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 17 10. Liedberg, B., et al., Sensors Actuators. 1083, 4, 299. 11. Flanagan, M. T., and Pantell, R. H., Electron Lett., 1984. 20, 12. Eur. Pat., 0112721, 1982. 13. Badley, R. A., Drake, R. A. L., Shanks, I. A., Smith, A. M., 968. and Stephenson, P. R., Phil Trans. B. 1987, to be published. Opto-thermal Transient Emission Radiometry: a New Surface Analysis Technique R. E. Imhof, D. J. S. Birch and F. R. Thornley Photoph ysics Research, Strathclyde University, Glasgow G4 ONG J. R. Gilchrist Edinburgh Instruments Ltd., Research Park, Riccarton, Currie, Edinburgh EH14 4AP A host of spectroscopic techniques has been invented in recent years for studying optical, thermal and related properties of “real” materials, such as powders, surface coatings, polymer composites, catalysts, etc.Their common feature is the use of modulated optical excitation to generate a signal from the degraded heat in the sample. Photo-acoustic Spectroscopy The most popular technique at present is photo-acoustic spectroscopy (PAS), developed in the early 1970s’ from A . G. Bell’s pioneering work. The two key parameters in such experiments are the wavelength, h, and the modulation frequency, v, of the excitation light. A measurement of signal changes with wavelength explores the absorption spectrum of the sample. A measurement of signal changes with modulation frequency explores thermal conduction at different depths below the surface, because the thermal diffusion length, 1-1, is given by p = (D/xv)”2 where D is the thermal diffusivity.There are two fundamental limitations of PAS. Firstly, theoretical analysis of the signal in terms of the physical properties of the sample is difficult, because of the indirect means of detection. Secondly, it is difficult to measure the frequency dependence of the sample response, because of the general problem of resonances in acoustic systems. This problem has been compared to measuring the properties of a hammer by hitting a bell with it! Photothermal Radiometry Photothermal radiometry (PTR)* overcomes these difficulties by using the thermal infrared emission from the sample as the information carrier. The “grey body” infrared power, W , emitted at temperature T , is given by W = EO T4 where E is the emissivity and o is the Stefan - Boltzman constant.A small change of temperature, bT, caused by the absorption of excitation light, leads to an increase of emitted power by an amount bW, where 6W = ( 4 ~ 0 73) 6T In this approximation, infrared detection gives a direct measure of degraded heat in the sample. There are no heat-transfer interfaces nor resonant components. Theoretical analysis of this signal generation path and measurement of the frequency dependence of the sample response are now straightforward. Opto-thermal Transient Emission Radiometry The frequency domain can be explored either by narrow-band (signal amplitude and/or phase versus modulation frequency) or by wide-band (impulse response) techniques.The relative merits of these approaches are often hotly debated, despite the fact that they are related through the Fourier transformation. In practical terms, the measurement of impulse response, as in opto-thermal transient emission radiometry (OTTER) ,3,4 offers important advantages: efficient signal capture by means of high speed transient averaging,5 a band width of sampled frequencies, ranging potentially over tens of MHz, the availability of powerful methods of data analysish.7 and the availability of pulsed lamps and lasers spanning wide ranges of intensity and wavelength. Two main theoretical models have found application to date. An opto-thermal decay function of the form Sl(t) = exp (t/tl) erfc[(t/t,)l’2] is often appropriate for homogeneous samples, with thermal emission from the surface (see reference 4 for a detailed discussion).The opto-thermal decay time, T ~ , is related to the s - I 1 I 1 I L 0 12 24 36 48 60 Time/s x 10 5 Fig. 1. Opto-thermal decay curves for fresh and weathered paint films. The decrease in opto-thermal decay time is caused mainly by photochemical degradation, leading to changes in the optical absorp- tion properties of the polymer matrix18 absorption coefficient, a, and the thermal diffusivity, D, of the sample by Fig. 1 shows examples of opto-thermal decay curves from fresh and weathered paint films,s with best-fit functions, S , ( t ) , superimposed. Opto-thermal decay times thus obtained are useful in two ways. Firstly, in non-destructive testing, they are empirical parameters indicating degradation.Our experiments show that they are particularly sensitive in the early stages of degradation. Secondly, in fundamental research into degrada- tion mechanisms, they give information about changes of thermal and optical properties that would be difficult to obtain by other means. S , ( t ) has also been used to analyse signals from powders, biological samples, optical thin films, etc. (see reference 9, for example). In our recent work on thermally insulating films on thermally conducting substrates,lO we have used an opto-thermal decay function of the form where the exponential decay time L and D are the thickness and thermal diffusivity of the film and s is a “substrate constant,” which gives a measure of the effectiveness of the substrate as a heat sink.With a reliable thermal contact, this decay time gives a relative measure of thermal diffusivity or film thickness. With bonded films, variations in s can give information on the effectiveness of the ANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 bond or, with painted metal panels, for example, corrosion onset at the interface. Conclusion OTTER, already useful in a number of application areas, has the potential for further development in experimental tech- niques, theoretical understanding and data analysis. We thank the Paul Instrument Fund and SERC for equipment grants, and SERC and ICI Paints Division plc for a co- operative research studentship held by one of us (J.R.G.). References 1. 2. 3. 4. 5 . 6. 7. 8. 9. 10. Harshbarger, W.R., and Robin, M. B., Acc. Chem. Res., 1973, 6, 329. Nordal, P.-E., and Kanstad, S. O., Phys. Scripta, 1979. 20, 659. Tam, A. C., and Sullivan, B., Appl. Phys. Lett., 1983,43.333. Imhof, R. E., Birch, D. J. S., Thornley, F. R., Gilchrist, J. R . , and Strivens, T. A., J . Phys. E: Sci. Instrum., 1984. 17, 521. Gilchrist, J. R., Hallam, A . , Imhof. R. E.. and Birch, D. J . S . , Comput. Enhanced Spectrosc., 1986, 3, 41. Imhof, R. E., and Birch, D. J. S., “Proceedings of the International Conference on Deconvolution and Reconvolu- tion of Analytical Signals, Nancy. 1982,” ENSIC-INPL. pp. Birch, D. J . S . , and Imhof, R. E.. Anal. Insmim., 1985, 14, 293. Imhof, R. E., Birch, D . J. S . , Thornley, F. R . , Gilchrist. J . R.. and Strivens, T. A., J . Phys. D: Appl.Phys., 1985, 18, L103. Imhof, R. E., Birch, D. J. S . , Thornley, F. R . , and Gilchrist, J. R . , Poster presentation, Xth IUPAC Symposium on Photochemistry, Interlaken, July, 1984. Imhof, R. E., Thornley, F. R., Gilchrist, J . R . , and Birch, D . J. S . , J. Phys. D: Appl. Phys.. 1986, 19, 1829. 4 1 1-423. Inductively Coupled Plasma Atomic Emission Spectrometry (ICP - AES) Source Housed in a Glove Box for Alpha-active Material Containment T. Berry and K. C. Macleod United Kingdom Atomic Energy Authority (Northern Division), Dounrea y Nuclear Power Development Establishment, Thurso, Caithness KW14 7TZ An Applied Research Laboratories (ARL) Model 34000C Quantovac 72-channel direct reading emission spectrometer has been in use for elemental analyses at Dounreay Nuclear Power Development Establishment (DNPDE) since 1979, and a fume cupboard was built around the ICP source in 1980 to allow its use with slightly radioactive solutions.Details have been published of the application of this instrument to the routine determination of trace impurities in the sodium coolant of the Prototype Fast Reactor,lJ and in uranium metal and compounds following solvent extraction separation of the uranium.3>4 An assessment of the possibility of using this instrument for analysis of plutonium solutions4 found that, following solvent extraction separation of the plutonium, up to 20 pCi ml-1 could remain in the 2 ml of solution analysed on the ICP. It was considered advisable to limit the alpha activity for the fume cupboard trials to 80 nCi ml-1, so a 250X dilution was used.Applied Research Laboratories have now supplied an ICP source, which has been modified to be suitable for housing in a glove box, together with a glove box interface to an ARL Model 3520 spectrometer. The spectrometer provides a novel solution to having the wavelength selection flexibility of a scanning monochromator, without a serious time penalty when performing sequential analysis of several elements, over the wavelength range 175.G797.0 nm. This is achieved by having 255 fixed exit slits mounted on a frame, and by moving the primary slit under computer control to locate the required wavelength in the nearest exit slit. One of two detectors is moved simultaneously behind this exit slit, depending on whether the wavelength is in the ultraviolet region or in the visible and infrared region of the spectrum. The glove box system was designed by the UKAEA and installation of the ICP - glove box - ARL 3520 at DNPDE was completed in January, 1986.This paper describes the glove box system and experiments to measure the particle size distribution of solutes vaporised in the ICP and subsequently condensed. It also describes penetra- tion tests on the filters that form an important part of the containment. Prior to using this facility with radioactive solutions the operating conditions are being extensively investigated. This has included calibration of the wavelength scale, optimisation of the ICP variables, quantitative calibration for individual elements and measurement of spectral line interferences. The results of these investigations are tabulated.Only natural thorium and uranium, of the actinides, have been included in the work to date. On completion of theANALYTICAL PKOCEEDINGS. JANUARY 1987, VOL 23 19 inactive work, neptunium, plutonium, americium and curium will be included, as pure standard solutions of their long-lived isotopes become available. A problem with radioactive elements, and plutonium is no exception, is that transmutation to daughter products is a continuous process, so that the impurity concentration is always increasing. Analytical results should always include the date of analysis to be of full value. A further ARL ICP source is being housed in an a, 0, y-containment facility, and is scheduled for completion in 1987.This facility will share the 3520 spectrometer, which will be moved between fixed containment facilities for this purpose. ICP Glove Box System The glove box system is shown in Fig. 1 and, following the Karlsruhe practice,5 there are separate compartments, referred to as the ICP box and the work box. The ICP box contains the peristaltic pump, concentric capillary nebuliser, conical spray chamber with impact bead and drain tube, the drainage vessel, the ICP torch and radiofrequency (RF) induction coil, and the ignition spark electrode. The torch is surrounded by a small stainless steel box fitted with a chimney to duct the ICP argon away and having a hinged side carrying a viewing port; the window filters out the ultraviolet and infrared radiation and includes a wire mesh RF barrier.Fig. 1. box, ARL 3520 and RF generator General view of the equipment showing the work box, ICP Selection of the 4-mm deep horizontal section of the plasma seen by the spectrometer is by manual adjustment of the plasma torch height relative to the spectrometer. A 15-cm focal length quartz lens focuses the image of the selected section of plasma on the entrance slit of the spectrometer at a reduction of 0.7. A ceramic tube encloses the light path within the glove box, and is purged with argon to prevent the attenuation of the vacuum ultraviolet wavelengths that would be produced by air. ARL modifications to the standard ICP source allow the RF tuning unit, which compensates automatically for changes in impedance of the plasma during start up, and the radiator in the closed-loop water circuit for cooling the RF coil, to be sited outside the plasma box. The valves controlling the four argon flows (cooling, plasma mpport, sample aerosol conveyance and external optical-path purge), together with the start and stop switches, the peristaltic pump controls and the nebuliser tip wash reservoir and control switch, have also been made remote and are mounted in a separate control box, which is conveniently wall mounted.In addition, the Tesla coil circuit that generates the high voltage sparks used to initiate the plasma has been repositioned to allow exterior mounting. The ARL interface to the 3520 spectrometer consists of a short, circular, stainless steel bellows section, carrying a quartz lens in a special housing, and a positive location mount for the spectrometer.The mount allows quick separation and re- coupling of the spectrometer to allow it to be shared with other emission sources, in particular the ICP for use with inter- mediate levels of a, p and y activity. The lens can be changed without breaking the containment. The ICP box roof has a 14 cm diameter hole immediately above the plasma torch, which connects the plasma box proper to an upper chamber, extending above, but normally isolated from, the work box. This section contains four parallel HEPA filter holders with 50 ft3 min-1 filters, and its roof is penetrated by the four extract pipes, one from each filter housing. The filter chamber has three glove ports for use in filter changing operations, and filters are transferred to and from the work box through a communicating trap door, which is normally held shut against a gasket seal.The arrangement of the plasma box extract, immediately above the plasma, ensures that the air flow past the plasma is parallel to its vertical axis, and there is no sidestream that could upset the precise central alignment of the plasma about the spectrometer optical axis. In use, the plasma box air tempera- ture only rises 1 "C from the plasma heat transfer. The ICP and work boxes have a common wall with a transfer port, which is normally closed by a bung, and the narrow plastic capillary tube, which is joined to the peristaltic pump, passes through a sealed penetration of this bung. In this way the solutions used can be handled through the gloves in the work box without the resulting pressure surges affecting the plasma.When not in use the glove ports are sealed with bungs, inserted between the gloves and box. The work box has its own two extract filters and extract pipes, but contains no fixed apparatus. Transfer of materials, including extract HEPA filters, is via a la Calhene dual concentric fitting in the work box wall, which allows material to be transferred between the appropriate cylindrical containers forming part of the la Calhene posting system6 and the work box. The plasma box and work box have their own inlet HEPA filters, rated for flows of 250 ft3 min-1 and 50 f t 3 min-1, respectively. The extract branch-pipes for the plasma and work boxes join separate manifolds, which lead to separate vortex amplifiers,' from where they are connected into the manifold from the extract pump.After the extract pump a further HEPA filter leads to the 20 m atmospheric discharge chimney stack. The vortex amplifiers, in conjunction with the glove boxes inlet and outlet regulation valves, maintain the normal glove box depression at about 5 cm water gauge below atmospheric pressure. In the unlikely event of a partial breach of contain- ment they operate to increase the air flow so that no material escapes from the containment. The ICP radiofrequency power supply, external to the box, is designed for intermittent periods of use at a forward power to the plasma of 2 kW, but will usually be operated below its maximum continuous rating of 1.6 kW. The calorimetric heat input into the plasma has been shown to be about half the indicated forward power,s so the air flow through the plasma box has been designed to dissipate up to 1 kW of heat whilst keeping the wall temperature below 55 "C.A metal shield above the plasma, but in the filter chamber, protects the HEPA filters from heat radiation. Connection points have been provided upstream and down- stream of the extract filters to allow routine checks of the filtration efficiency to be made. Currently, these checks are carried out by injecting an aerosol of dioctyl phthalate (DOP), which is measured by a near forward light scattering photo- meter, including diameters down to 0.1 pm.9 Experimental Determination of the Particle Sizes Generated by the ICP Operations and the Filter System Efficiency It was decided to measure the size distribution of particles generated by the ICP.This was done by feeding suitableANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 20 Table 1. Particle size distribution from ICP operations Number of particles per m3 air Number of particles per m3 air Particle sizeiFm 0.3 0.4 0.5 0.6 0.7 1.4 1.5 1.6 1.7 1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.5 4.0 4.5 5.0 6.0 6.5 7.0 1 M HNO,, 1 . 2 6 ~ U 137 678 430 232 376 592 123 344 296 184 161 376 72 232 65 596 63 732 136 206 96 426 104 300 72 840 80 842 56 488 151 374 109 966 48 074 56 866 99 332 30 888 30 546 28 384 1 M HN03 8 704 25 614 20 768 6 436 14 962 7 786 3 420 3 224 2 892 6 132 4 234 4 474 3 004 3 350 2 244 5 610 3 982 1672 1876 3 194 936 846 884 Particle sizeipm 7.5 8.0 9.0 10 12 13 14 15 16 17 18 19 20 22 24 26 28 30 35 40 45 50 55 1 M HN03.1 . 2 6 ~ U 19 896 33 064 19 192 43 730 32 472 32 196 24 502 8 216 4 930 6 634 3 114 3 434 2 248 3 848 2 930 2 412 1646 1294 1984 1326 744 762 1396 1 M HNO, 560 924 490 1032 208 200 138 44 16 44 44 46 16 44 28 24 10 8 10 8 2 6 8 Table 2. ICP and ARL 3520 operating conditions ICP Henry Radio-Inc. (Supplied by ARL) Power supply: 27.12 MHz operated at 1.15 kW forward power, <5 W reflected power Nebuliser: Meinhard concentric capillary operated at 300 kN m-2 Ar pressure and fed with solution by a peristaltic pump at 1 ml min-1 Spray chamber: Conical, 50-ml volume, with impact bead ICP torch: Fixed concentric fused silica tubes Ar flow-rates (1 min-1): Coolant 12 Plasma 0.8 Sample transport 1 .0 Optical path purge 1.0 Plasma viewing height above top of load coil: 19 mm Spectrometer ARL 3520, with vacuum option Grating: Concave reflection, 1080 grooves mm- with access to orders 1-4 Configuration: I-m radius, Paschen - Runge mount Primary slit width, 20 pm Exit slits width, 50 pm Order sorter: One of 7 filters selected by computer control Signal integration time, 2 s Number of measurements of analysis solutions: 10 Slewing time between lines, less than 1.5 s Background measurements, on peak or both sides of peaks Computer: Digital Equipment Company (DEC) LSI-l1/04 with 64 kb RAM Permanent storage device, 10 Mb Winchester (5Y4 in floppy disc back Hard copy device, DEC LA210 letter printer Video terminal, DEC VT 240 Software, ARL SAS/DPS-11 (Spectrometer Automation System and Data Processing System-1 1) UP) solutions and counting and sizing the particles in the air stream before the extract filters.The measuring equipment was the Kratel AR EDM-32 forward scattering visible light pho- tometer, which covers the size range 0.3-50 pm diameter. The extract filtration efficiency for the fume cupboard housing the separate ICP had been tested with the same instrument, but the inlet air from the laboratory was not filtered in this instance so that the contribution from particles in the laboratory air was not assessed separately but was included in the total particles measured in front of the extract filter.4 In the instance of the filtered inlet glove box, the contribution of particles from the laboratory air was very slight, so that the measurements included a direct measure of the particles emanating from the ICP.The results from the Kratel equipment are given in Table 1. The inlet and outlet filtration systems were also tested by the routine DOP method, and the penetration was found to be less than 0.05% on a mass basis. Commissioning Work As part of the commissioning work, before using this facility to determine impurity elements in plutonium nitrate solutions recovered from the reprocessing of irradiated Prototype Fast Reactor fuel, the ICP operating parameters have been optimised for a number of individual elements using the variable step size sequential simplex method. 10.11 Compromise parameters for multi-element analysis have been chosen and are included in Table 2.This table also includes the other operating conditions. The exact locations of sensitive analysis lines, their calibra- tion constants (net mV per pg of element per ml of solution analysed) and detection limits have been determined for 20 elements and are given in Table 3. Spectral line interferences have been investigated empirically from 20 elements, but the facility has not been used with radioactive solutions, so natural uranium and thorium are the only actinide elements measured to date. The interference matrix examined to date is given in Table 4. Results The main results are included in Tables 1-4. Even at impurity concentrations well below the specified upper concentration limit the coefficient of variation for a single determination is about 1 'YO.Conclusions The ICP installation in a glove box interfaced to a direct reading spectrometer functions as intended and will allow more precise, and more efficient, analyses of impurities in medium21 ANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 Table 3. Representative analytes, wavelengths, calibration factors and detection limits Symbol A1 B Ca co Cr Fe Hg Mg Mn Wavelengthlnm 308.215 394.401 396.152 182.589 208.959 317.933 393.366 422.673 228.802 237.862 205.552 206.149 267.716 259.940 271.440 273.955 371.994 184.950 194.227 279.080 279.553 257.610 293.306 294.920 Anal ytes mV per pg ml- 0.45 0.72 0.94 0.22 1.01 6.4 8.3 0.69 0.46 1.2 0.85 17.6 11.1 0.47 3.1 1.7 0.24 0.20 1.2 51 .0 8.4 21.0 268 364 ng ml- 50 60 30 150 40 8 0.1 9 48 74 29 37 2 4 110 13 80 120 130 20 0.2 0.8 14 5 Analytes Symbol Mo Na Ni P Pb Sr Ti Th U Zn Wavelengthlnm 202.030 281.615 330.237 588.995 589.592 221.647 227.021 23 1.604 178.287 177 SO0 255.328 216.999 220.353 346.446 407.771 421.552 308.802 336.121 337.280 374.120 385.958 409 .0 14 424.167 202.55 1 206.191 mV per pg ml-I 5.3 12.7 1.5 7.2 2.34 0.77 0.25 0.45 0.06 0.08 0.03 11.2 10.0 6.6 1565 863 17.5 43.0 33.0 0.80 2.0 1.8 1.2 0.79 0.92 ngml-l 20 8 80 16 60 30 60 40 310 250 800 50 50 15 0.2 0.3 5 1 5 30 130 110 330 30 20 213.856 4.2 3 Table 4.Partial interference matrix. The entries in the matrix are interference equivalent concentrations (IEC) defined as the apparent analyte concentration in mg 1-1 produced by a 1 mg ml-* solution of the interferent Analytes Symbol A1 B Ca c o Cr Fe Mg Mn Mo Na Ni P Sr Ti U Zn nm 308.215 394.401 396.152 208.959 3 17.933 393.366 422.673 237.862 206.149 267.716 259.940 271.440 273.955 371.994 279.080 279.553 257.610 293.306 294.920 281.615 330.237 588.995 589.592 227.021 231.604 255.328 346.446 407.771 421.552 308.802 336.121 337.280 385.958 409.014 424.167 202.551 206.191 213.856 Interferent A1 Co Cr 3.0 1.6 2.3 Fe Mg Mn 2.1 1 .0 1.2 72 3.4 0.9 0.1 0.3 2.3 120 13.3 0.6 0.3 1.1 0.4 0.4 220 55 8.3 1.4 Mo 1.6 0.7 15 0.2 3.1 0.1 0.1 NI 3r i n 1 1 U 111 42 11.0 0.4 18 9.3 1.6 8.9 7.6 2.7 2.2 3.3 2.2 0.5 11.8 64 37 3.0 15 3.9 5.6 5.1 2.4 6.7 5.7 3.5 17 21.3 320 380 0.2 0.2 7.8 0.1 - 0.3 0.2 0.3 3.3 0.2 0.3 1.4 1.8 88 0.3 2.5 Order 2 2 2 3 2 2 1 2 3 2 2 2 2 2 2 2 2 2 2 2 2 1 1 3 2 2 2 1 1 2 2 2 2 1 1 3 3 322 ANALYTICAL PROCEEDINGS, JANUARY 1987.VOL 24 level alpha-active material than was possible using a spark source coupled to a spectrograph. The particle size measurements were made by Dr. D. Graham and Mr. D. Webster of Reprocessing Development Group, and assistance with the operation of the ICP and spectrometer was provided by Mr. S. Lowes during a period at UKAEA, Dounreay , whilst an undergraduate of Skeffield City Poly- technic, studying for the Degree of BSc (Applied Chemistry). References 1. 2. Berry, T., Macleod, K. C., Christie, A. C., and Cunningham, J. A., Analyst, 1983, 108, 189. Hendrie, R. W., Macleod, K. C., and Berry, T . , “Determina- tion of Impurities in Reactor Grade Sodium, Without Precon- centration, by Inductively Coupled Plasma Atomic-emission Spectrometry,” Second Biennial National Atomic Spectro- scopy Symposium, Leeds, July 10-13, 1984.3. 4. 5. 6. 7. 8. 9. 10. 11. Hendrie, R. W., Macleod, K. C., and Thomson. B. J.. “The Determination of Impurities in Uranium Solutions by Induc- tively Coupled Plasma Optical Emission Spectrometry.’’ Analyticon ’84, London, September 4-6, 1984. Macleod, K. C., Hendrie. R. W., and Berry, T., “Application of Inductively Coupled Plasma Atomic Emission Spectrometry to Measurement of Impurities in Uranium and Plutonium,” International Conference on Analytical Chemistry in Nuclear Technology, KfK, Karlsruhe, FRG, June 3-6. 1985. Karnowski, K.-D., and Berg, R., Labor. Prax., 1981, 5 , 574. Lefort, G . , and Vertut, J., At. Energy Rev., 1973, 11, 95. “Vortex Amplifiers: a No Moving Parts Controller for Use on Ventilation Systems,” Systems Engineering Design Office.Service and Sales, UKAEA, Risley, Warrington. Greenfield, S . , Jones, I. L., McGeachin. H. McD., and Smith. P. B., Anal. Chim. Acta, 1975, 74, 225. Stevens, D. C . , and Green, B. L., “In situ Filter Testing Using DOP Aerosol and Photometric Detection,” AERE Report 11255, 1984, UKAEA, London. Spendley, W., Hext, G . R . , and Himsworth, F R . , Techno- metrics, 1962, 4, 441. Nelder, J. A . , and Mead, R . , Comput. J., 1965. 7. 308. ASIA: Atomiser, Source, Inductively Coupled Plasmas, in Atomic Fluorescence Spectrometry 15 Stanley Greenfield and Maryanne Thomsen Loughborough University of Technolog y, Department of Chemistry, Loughborough, Leicestershire LE 1 1 3TU - Atomic fluorescence is not in itself new.It is a technique which, hitherto, has not captured the imagination of the analytical community, mainly because of a paucity of suitable sources and atomisers, the difficulty of using the technique in a simul- taneous multi-element mode and, above all, the absence of a commercial instrument of general acceptability. The use of inductively coupled annular plasmas in atomic fluorescence spectrometry (AFS) is comparatively new. 1-18 Moreover, their use promises to have a similar revolutionary effect to that which they have had on emission spectrometry, as an ICP has many of the requirements for both source and atomiser. The essential requirement for an excitation source in AFS [and in atomic absorption (AA)19] is that it shall have a high radiance over the centre of the absorption line of the analyte atoms, good short-term and long-term stability, be available for a large number of elements, be simple to operate and have a long life time.On the other hand, the main requirements for an atomiser are that it should be capable of producing a high density of analyte atoms and that these atoms should have a long residence time in the optical path. It should have high volatilisation efficiency to avoid light scatter, low quenching properties and low background radiance. Again, good reproducibility and ease of handling are desirable. Atomic fluorescence is the process of radiational activation of ground state atoms followed by a radiational de-activation, and the fluorescence spectrum is relatively simple, being confined principally to the resonance lines used in the excitation source.Emission, on the other hand, depends upon collisional excitation of the spectral transitions, and the resultant spectrum consists of a multitude of spectral lines from all the accompanying elements, which, in turn, leads to problems of spectral interference, exacerbated by the high temperature of the source if an ICP is used. The conditions for spectral interference are more stringent for AFS than for AES and there are fewer such interferences. It is this aspect of AFS that is the principal reason for a rigorous investigation of the technique, part of which this paper describes. The system employed at Loughborough uses a high power ICP, which acts as a line source to excite fluorescence in ground state atoms produced in the tail-flame of a low power ICP.It has been described in detail elsewhere,15,17 together with an account of its operation, curves of growth, sensitivity and linear dynamic range. In general, the limits of detection are in the same p.p.b. range as atomic emission spectrometry (AES) for the non-refractory elements and not as good for the refractory elements, where it is necessary to use an alkane gas or an 20 - (a) l 5 t l o t 5 t 0 200 210 220 23C Wavelength nm Fig. 1. Freedom from background shift in ASIA. The lower trace ( b ) is a scan of the 19G220 nm region with de-ionised water in the atomiser plasma and a 5% zinc solution in the source plasma. (The fluorescence wavelength for zinc is 213.9 nm.) The upper trace (a) is a scan with 10000 p.p.m.of aluminium in the atomiser plasma and a 5% zinc solution in the source plasma. High amplifier gain was used in both scans; slit width, 3.6 mm; time constant. 1 s; scan speed. 5 nm min-lANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 > E - m & 30 .- v) a, c a, 0 ?! 3 0 >. v) C a, C a, > - 2 0 - .- c .- .- 1 0 - - a, LT 23 - alcohol to scavenge the oxygen which prevents fluorescence being produced,20 or so it is thought. Spectral Interference: AFS versus AES Larson and FasseP have shown that approximately 2500 p.p.m. of aluminium will produce a background shift of one order of magnitude in the 190-220 nm region in ICP - AES due to radiative recombination continua. Because the ASIA instrument employs a.c.coupled electronics, which discrimi- nate against changes in d.c. signals, it is not so susceptible to this type of background interference as can be seen from Fig. 1, where the addition of as much as 10 000 p.p.m. of aluminium has little effect on the background. These authors also describe in the same paper another type of spectral interference, that occasioned by collisional line broadening. They show the effect of 1000 p.p.m. of calcium on the aluminium lines at 394.4 and 396.2 nm. A background shift is seen to extend as far as 10 nm from the calcium ionic lines at 393.4 and 396.8 nm. This phenomenon is also potentially present in ASIA and would not be avoided by a.c. coupling of the electronics. However, Fig. 2 shows that 10 000 p.p.m. of calcium, when aspirated into the atomiser plasma of the ASIA system, does not have the same marked interference that 1000 p.p.m.of calcium has in emission. 390 395 Wavelengthinm 400 Fig. 2. Freedom from collisional broadening interference in ASIA. The lower trace ( b ) is a scan of the 390-400 nm region with de-ionised water in the atomiser plasma and a 5% aluminium solution in the source plasma. The upper trace (a) is a scan with 10000 p.p.m. of calcium in the atomiser plasma and a 5% solution in the source plasma Winge, Fassel, Peterson and Floyd22 have shown the interference of 200 p.p.m. of chromium and 1000 p.p.m. of iron on 10 p.p.m. of lead. The emission of lead is 283.31 nm, those of chromium 283.23 and 283.34 nm and that of iron 283.31 nm, and there occurs marked spectral overlap.Fig. 3 shows the fluorescence peak of lead at 283.31 nm, produced by the ASIA instrument, and no interference from the same amounts of iron and chromium as were used in the emission example. The major resonance line of zinc, at 213.856 nm, is subject to direct spectral interference by the copper 213.853 non- resonance transition in emission. There is another zinc line at 206.2 nm, but this is four times less sensitive. Fig. 4 shows a graph of the relative fluorescence intensity obtained by nebulising a 5% zinc solution into the source plasma and an increasing concentration of copper into the atomiser plasma. The monochromator was set to the zinc resonance line of 213.856 nm. If there was no fluorescence interference from copper it might be expected that no signal would be apparent.As can be seen in Fig. 4, there was a signal which increased with increasing copper concentration. However, the slope of the line varied with the source of the copper, and although the signal could be due to copper fluorescence it is much more probable that it is due to a zinc impurity in the allegedly pure copper materials. I 260 270 280 290 300 0 Wave1ength:nrn Fig. 3. Wavelength scan over the fluorescence peak of lead at 283.31 nm, showing the absence of spectral interference from chromium and iron. A , Lead (10 p.p.m.); 0, chromium (200 p.p.m.); X. iron (1000 p.p.m.) Fig. 5 shows a standard addition plot of the zinc content of a 3% copper matrix prepared from two sources of copper, and determined on the ASIA instrument by AFS.The concentra- tion of zinc in the copper sulphate and copper metal solutions were found to be 1.7 and 0.125 p.p.m., respectively, corre- sponding to 58 and 4 p.p.m., respectively, in the solid. Neither of these concentrations could be determined on the ASIA instrument in the emission mode. The discrimination obtain- able by the fluorescence technique arises from the low quantum efficiency that the non-resonance copper line has in fluorescence. It is interesting to note that there is some interference from the non-resonance line in atomic absorption because in Fig. 5 it can be seen that the graph for zinc without any added copper is steeper than those with copper. This is caused by absorption of some of the zinc radiation by the copper. Non-resonance Transitions in AFS All the transitions so far discussed have been resonance transitions, where the radiational excitation and de-excitation processes are between the same upper and lower energy levels.As a consequence, the absorbed and emitted radiation are of the same wavelength. Other transitions can be used of which the direct line transition of barium has been investigated in this work. In direct line fluorescence, where only the upper level is common to the excitation and de-excitation processes, the excitation wavelength differs from that of the fluorescence line, affording further scope for avoiding spectral interference. The two most intense emission - fluorescence lines of barium occur at 455.403 and 614.172 nm. They were investi- gated by using an interference filter, which isolated the line at 455.403 nm.(The spectral window of the filter was 450-500 nm, with a 28% transmittance.) The observed fluorescence, when the filter was not used, was caused by a combination of resonance and non-resonance fluorescence transitions result- ing from the multiple line excitation of the source. With the24 ANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 filter in place there was a marked reduction in the signal, as might be expected from the known transmittance of the filter, but it was quite clear that the observed fluorescence at the two lines studied was due to the 455.403 nm line excitation, i.e., resonance fluorescence at 455.403 nm and non-resonance fluorescence at 614.172 nm. v) a, C a, u 0.4 0 3 0 >. - Lc Lc c. ’Z 0.2 ’ a, f c .- Concentration of Cu in atomiser plasma, % Fig.4. concentration of copper Relative fluorescence intensity at 213.856 nm with increasing Apart from the possibility of avoiding spectral interference, non-resonance fluorescence enables multi-pass optical systems to be used. This is not easy to accomplish in resonance fluorescence, as light scattered from the source beam causes 50 > E -._ 1. v) c a, c (0 C 0) a, 0 C a, m c .- c .- - .- * 25 z 3 u C N - .I- .- 2 1 0 Zinc, p.p.rn. 1 2 Fig. 5. Standard addition graphs of the zinc content of a 3% copper matrix prepared from: A , copper(I1) sulphate, AnalaR; 0, BCS copper standard; x zinc aqueous solution. A, 213.9 nm; slit width, 3.6 mm; 5% zinc in source plasma problems. However, when the excitation wavelength is differ- ent from the fluorescence wavelength, as in non-resonance work, scatter is no longer a problem.Thus, with barium, a double-pass optical system at the atomiser plasma increased the signal by a factor of two. Conclusions It has long been known that AFS has one great advantage over AES, namely freedom from spectral interference. This present work has been undertaken to demonstrate this fact by taking a few examples of known spectral interference which occur in AES and demonstrating that these same interferences do not occur when the examples are run on the ASIA instrument. Earlier work17JO has shown that this instrument using two ICPs also retains many of the properties associated with ICP - AES, sufficiently so, in the opinion of the authors, to justify further investigation of the technique and improvement of the ASIA instrument. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. References Hussein, A. M. Ch., and Nickless, G., Paper presented at the 2nd ICAS, Sheffield, England, 1969. Montaser, A., and Fassel, V. A., Anal. Chem., 1976,48,1490. Montaser, A., Spectrosc. Lett., 1979, 12(10), 725. Pollard, B. D., Blackburn, M. B., Nikdel, S., Massoumi, A., and Winefordner, J. D., Appl. Spectrosc., 1979, 33, 5. Omenetto, N., Nikdel, S . , Bradshaw, J. D., Epstein, M. S . , Reeves, R. D., and Winefordner, J . D., Anal. Chem., 1979, 51, 1521. Epstein, M. S . , Nikdel, S . , Omenetto, N., Reeves, R., Bradshaw, J., and Winefordner, J. D., Anal. Chem., 1979, 51, 2071. Omenetto, N., Nikdel, S . , Reeves, R. D., Bradshaw, J. D., Bower, J. N., and Winefordner, J. D., Spectrochim. Acta, Part B , 1980,35, 507. Demers, D. R., and Allemand, C. D., Anal. Chem., 1981,53, 1915. Cavalli, P., Omenetto, N., and Rossi, G., At. Spectrosc., 1982, 3, 1. Omenetto, N., Cavalli, P., and Rossi, G., Rev. Anal. Chem., 1982, 5, 185. Uchida, H., Kosinski, M. A., and Winefordner, J. D., Spectrochim. Acta, Part B, 1983, 38, 5. Kosinski, M. A,, Uchida, H., and Winefordner, J. D., Talanta, 1983, 30, 339. Kosinski, M. A., Uchida, H., and Winefordner, J. D., Anal. Chem., 1983, 55, 688. Omenetto, N., Human, H. G. C., Cavalli, P., and Rossi, G., Spectrochim. Acta, Part B, 1984, 39, 115. Greenfield, S., Anal. Proc., 1984, 21, 61. Long, G. L., and Winefordner, J. D., Appl. Spectrosc., 1984, 38, 563. Greenfield, S., and Thomsen, M., Spectrochim. Acta, Part B, 1985, 40, 1369. Krupa, R. J., Long, G. L., and Windefordner, J. D., Spectrochim. Acta, Part B , 1985,40, 1485. Greenfield, S . , Smith, P. B., Breeze, A. E., and Chilton, N. M. D., Anal. Chim. Acta, 1968, 41, 385. Greenfield, S . , and Thomsen, M., Spectrochim. Acta, Part B , 1986, 41, 677. Larson, G. F., and Fassel, V. A., Appl. Spectrosc., 1979, 33, 592. Winge, R. K., Fassel, V. A., Peterson, V. J., and Floyd, M. A., “Inductively Coupled Plasma Atomic Emission Spec- troscopy. An Atlas of Spectral Information,” Elsevier, Amsterdam, 1985.

ISSN:0144-557X    

DOI:10.1039/AP9872400014

出版商:RSC    

年代:1987

数据来源: RSC

摘要:

ANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 25 Equipment News Colorimetric Bioassay System The capabilities of the MasterLab system have been expanded to meet the needs of biological laboratories performing repeti- tive, routine ultraviolet - visible col- orimetric bioassays, including protein assays, immunoassays, microtitrations, RIAs and drug binding assays. Robotics allow for the automation of manually performed procedures, such as the Lowry assay. Use of a commercial software package such as Lotus 1-2-3 allows data to be analysed by the least squares tech- nique. Final protein concentrations are then calculated and data can be plotted in a user-programmable format. Perkin-Elmer Ltd., Post Office Lane, Beaconsfield, Buckinghamshire HP9 1QA. X-ray Microanalysis System A desk-top system, Model QX200, offers fully quantitative and qualitative analysis functions, including extensive data acqui- sition and manipulation, spectrum pro- cessing and sophisticated display capabili- ties, such as on-screen Peak Seak, label- ling and KLM identification.A fully quan- titative X-ray microanalysis program is included as standard and the QX200 can be extended with a wide range of applica- tion programs, covering the analysis of thin films on substrates and digital image acquisition and processing of both X-ray maps and electron images. Link Systems Ltd., High Wycombe, Buckinghamshire. Photometer The MCP microprocessor controlled photometer, the latest addition to the Vitatron range of photometers, can be used for “one offs” or a series of photo- metric measurements.Wavelength selec- tion is by means of interference filters, zero blanking is automatic and concentra- tion readout is direct once a factor has been entered or a standard value has been programmed. A variety of cuvettes is available, including a drain cuvette, and a digital printer and chart pen recorder can also be provided. Vital Scientific Ltd., Huffwood Trading Estate, Unit 14, Partridge Green, West Sussex RH13 8AU. Gas Chromatography Columns DURABOND-Wax+ columns tolerate a wide range of solvents and temperatures (0-260 “C). The fused silica columns are bonded with a pure, cross-linked amor- phous polyethylene glycol phase which, in addition to being stable at high tem- peratures, will not crystallise at low ones. Thus, DURABOND-Wax+ columns are suitable for analysing early eluting polar compounds as well as those in the conven- tional range.Suitable for both splitless and on-column injection, the columns are available with three film thicknesses: 0.15, 0.25 and 0.5 pm. J & W Scientific Inc., 91 Blue Ravine Road, Folsom, CA 95630, USA. Liquid Chromatograph The Philips PU4100 is a fully integrated liquid chromatography system that can be upgraded from the simple isocratic mode into a fully automated quaternary chromatograph by use of plug-in optics, the system offers excellent stabil- ity, low noise and high sensitivity over the range 19&700 nm. First and second derivative chromatograms can be scanned to resolve overlapping peaks, and other features include programmed wavelength changes during analyses and automatic- ally synchronised background correction.Any one of nine factory-configured units can be ordered or a laboratory- tailored system can be designed. The top of the range quaternary system offers sample sequencing, highest performance gradient programming, a highly stable column oven and scanning ultraviolet - visible detection. Pye Unicam Ltd.. York Street, Cam- bridge CB1 2BX. Pyrolysis Unit for Gas Chromatographs The unit, which is suitable for use with either packed or capillary column chromatographs, consists of a constant temperature furnace into which samples are loaded using the SGE solids injector without introducing air to the system. The unit can be interfaced to most gas chro- matographs by means of a range of specially designed adaptors.Scientific Glass Engineering (UK) Ltd., Potters Lane, Kiln Farm, Milton Keynes, Buckinghamshire MK11 3LA. Philips PU4100 liquid chromatography system modules, including binary and quaternary solvent accessories, column ovens, auto- matic injectors and full detector scanning. A twin-piston pump design provides precise and uniform solvent flow-rates down to 1 pl min-1, with a range up to 5 ml min-1, and a microbore autoinjector allows full use of low dispersion tech- niques. Configured with the PU4110 ultra- violet - visible detector, with dual-beam Gas Sampling System for Gas Chromatography Made under licence from ICI, the system is based on the pressure balancing system developed by Dr. D. R. Deans. Called UNIVAP, it can easily be fitted to any gas chromatograph.Scientific Glass Engineering (UK) Ltd., 1 Potters Lane, Kiln Farm, Milton Keynes, Buckinghamshire MKll 3LA.26 ANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 Analytical Standards Kits for Chromatography The kits include alcohols, glycol ethers and glycols, phenols, amines, hydro- carbons, ketones, pesticides, PCBs, alde- hydes, fatty acids and esters, sulphur compounds, phthalate esters and McRey- nolds constants. The latest additions to the range are capillary probe solutions (used to compare columns and liquid phases as outlined by Grob), food addi- tives, essential oils and calibration mix- tures. Field Analytical Co. Ltd., P.O. Box 113, Weybridge, Surrey KT13 9UZ. Chromatography Accessories A new version of the maker’s poly- ethylene plugs for standard 2-ml vials has been introduced.The new plugs, refer- ence 11-PEP2, can be used in place of conventional crimp or screw caps; they have a height of 2 mm above the top of the vial. Polyethylene plugs for the stand- ard 4-ml vials used by Waters, Shimadzu and Kontron are also available and pro- vide an alternative to conventional screw caps with silicone or PTFE seals; the reference is 12-PEP4. The 06-CTV(A) is a new, 600 p1 tapered vial for chromato- graphy autosamplers. Amber in colour, it is approximately 30 x 7 mm and has been designed for the 60- and 100-vial carousels of instruments such as Dynatech Precision Sampling and Perkin-Elmer. It can be sealed with conventional 8 mm crimp caps or with one of the makers’ poly- ethylene plugs. A support sleeve, refer- ence WS-1, is available for lateral support where required.Two trays designed to hold chromatography autosampler vials are announced: the T-200, which holds 200 vials with a diameter of around 8 mm, and the T-105, which holds 105 vials with a diameter of approximately 12 mm. Chromacol Ltd., Glen Ross House, Summers Row, London N12 OLD. Diode Array Detector for HPLC The Merck - Hitachi L3000 enables spec- tra to be obtained for the components of a mixture as they pass through the detector. It can store up to eight spectra at the touch of a button or by timed event. The L3000 allows the detection wavelength to be changed at any point in the run. It features a ratio method, which gives precise determination of peak purity. There is also a compensation algorithm, which ensures good sensitivity and base line stability.Baird and Tatlock Ltd., P.O. Box 1, Romford, Essex RM1 1HA. HPLC Columns and Accessories The Chiral-1 Nucleosil column has been designed for the control of optical purity; it separates all chiral substances which can form chelate complexes with Cu2+ ions. HPLC columns, 100 x 7.8 mm, packed with the stable copolymer styrene - divinylbenzene, can be used over the entire pH range of 0-14 and can be employed for the rapid analysis of alco- hols, hydrophobic organic acids and glycols. A new cartridge system based on columns (100 or 250 mm) and guard columns, which can be coupled by means of a union, enables the user to couple them with or without reduction of cross section, as required. Also announced is a family of silica packings for HPLC; these are known as Nucleosil and Polygosil.Nucleosil is totally porous and is available in seven different pore diameters. Also porous, Polygosil is available in 60, 100, 300 or 500 8, pore diameter, giving nar- row fractionation. Series 7000 micro- syringes are suitable for the rapid injec- tion of minute volumes. Field Analytical Co. Ltd., P.O. Box 113, Weybridge, Surrey KT13 8BJ. HPLC Columns The Ultraprep Series columns, support- ing the maker’s Prep Series of chromato- graphs, are available in a wide range of chemistries, including C18, C3, FAC and HIC, in addition to the existing TSK (SW, PW, DEAE, CM and SP Phenyl) preparative products. The main features of the new columns include high sample loading capabilities, easy scale-up from analytical to preparative separations, high sample throughput and high performance packings.Beckman Ltd., Progress Road, Sands Industrial Estate, High Wycombe, Buckinghamshire. Preparative HPLC System The Prep-350 gradient chromatograph is a dedicated preparative system for the large-scale purification, isolation and separation of biomolecules. Methods developed on 4.6 and 10 mm i.d. columns with 2-5 pm media can be directly scaled up to the new 10 pm, 1 in and 2 in diameter columns. Even columns as large as 4 in diameter can be used. The Prep- 350 system has a flow-rate range of 5-350 ml min-1 for binary gradient oper- ation and up to 700 ml min-1 for isocratic operation. The pressure rating of 4000 Ib in-2 extends over the full range of available flow-rates.The system is avail- able with two high pressure dual piston pumps, one sample loading pump, a manual injector, a system controller, built-in fractionator and a variable wavelength ultraviolet - visible detector with preparative flow cell. Beckman Ltd., Progress Road, Sands Industrial Estate, High Wycombe, Buckinghamshire. Chromatography Automation Two CALS systems, the Phase 1 and Phase 2, are now available as a modular approach to computerising chromato- graphy instruments. They feature the maker’s MK5 Digimetry instrument inter- face coupler and PeakPro chromato- graphy software. Phase 1 is for the smaller laboratory, supporting 3-15 instruments and 1-4 simultaneous users, and it can be upgraded to Phase 2 (20-30 instruments, 8-10 simultaneous users) and even further to include 60 linked instruments and/or LIMS software. Non-chromatographic instruments can also be supported in these systems. PeakPro software will process chromatograms with up to 1000 peaks, identifying peaks and assigning base lines automatically.Beckman Ltd., Progress Road, Sands Industrial Estate, High Wycombe, Buck- inghamshire. Scanner for Thin-layer Chromatography Plates The Camag Scanner I1 gives detection at the low nanogram level in the absorbance mode and at the low picogram level in the fluorescence mode. All lamps and power sources for absorbance and fluorescence work for the wavelength range 200- 800 nm are standard and pre-aligned. The scanner features automatic lane changing and the ability to record spectra. Options are available for measuring electrophero- grams and circular and anti-circular plates, and data handling options range from the SP4270 integrator to a computer system using the Hewlett-Packard 9816 computer.Software includes video inte- gration, multi-wavelength scanning, spot optimisation and full calibration facilities. Baird and Tatlock Ltd., P.O. Box 1, Romford, Essex RM1 1HA. Water Monitoring Systems An HPLC-based system features Coulo- chem , a multi-electrode electrochemical detector with which it is possible to achieve direct injection and to perform the analysis isocratically . The Coulochem uses coulometrically efficient, porous graphite electrodes in series to provide the necessary sensitivity, stability and selectivity for monitoring phenols in water.The detection limit is some 50 times lower than the required level, that is the 0.5 p.p.b. limit laid down in EEC regulations. Severn Analytical, 36 Brunswick Road, Gloucester GL1 1JJ. Electrophoresis System Electro-4 is an electrophoresis system for DNA - RNA analysis. It includes a trans- illuminator, a gel tank, a power supply and a camera. Ultraviolet Products Ltd., Science Park, Milton Road, Cambridge CB4 4BN. Volumetric Solutions The Volusol range of standard volumetric solutions has been extended with the addition of 5 new solutions: 0.1 N EDTA, 0.1 N iodine, 0.1 N sodium thiosulphate,ANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 27 ~ / 9 sodium hydroxide and 0.282 N silver nitrate. The Volusol range of solutions are all accurate to within f O .l o / b and are available in the maker's new 2.5-1 glass bottles, except for the standard alkalis, which are marketed in 5-1 plastic contain- ers. Tetra-n-butylammonium hydroxide, 0.1 N , in toluene - methanol is also avail- able in 500-ml bottles. May and Baker Ltd., Liverpool Road, Eccles, Manchester M30 7RT. Titrator A new titrator is to be added to the Metrohm range. It will give a full visual screen display of the progress of the titration, showing curves, parameters, methodology and results. Roth Scientific Co. Ltd., Alpha House, Alexandra Road, Farnborough, Hamp- shire GU14 6BU. Pipetting System The Cetus Pro/Pette System is a com- puterised pipetting system specifically designed for biological procedures in microtitration plates. It transfers and dispenses micro-volumes of liquids with an accuracy and consistency which cannot be duplicated manually.It also automatic- ally picks up and ejects a r3w of dispos- able tips after each filling, aspiration, dilution or mixing cycle. The Pro/Pette can be programmed, using the hand-held controller, to transfer in 1-1.11 increments through the entire range of 1-200 yl. A typical serial dilution of an entire 96-well plate can be done in 1 min. Special software links pipetting protocols in any sequence for automating complete pip- etting procedures. Perkin-Elmer Ltd., Post Office Lane, Beaconsfield, Buckinghamshire HP9 1QA. Sample Changer The ST20 sample changer is a peripheral unit for the maker's DL20 compact titra- tor, in combination with which it can automate entire analysis sequences in routine operation, from the dilution of samples, via dispensing of auxiliary reagents, up to and including the actual titration, computation of the results and rinsing of the electrodes.The system calibrates the electrodes automatically. A printer, printer - plotter or a personal computer can be connected to the system, which can accept up to 40 sample weights from one of the maker's balances and reconcile the consumption after com- pletion of the titrations in the desired result calculation. Mettler Instrumente AG, CH-8606 Greifensee, Switzerland. Data Module for Protein - Peptide Sequencing The Model 900 data module controls the maker's gas phase sequencer and on-line analyser, performing simultaneous data acquisition, reporting and storage.It also provides fully automated assignment of amino acids from the sequencing of proteins and peptides. Applied Biosystems Inc. , 850 Lincoln Centre Drive, Foster City, California 94404, USA. Chlorine Monitor A new solid-state, thin-film, semiconduc- tor, diffusion type sensor and also a control module, Model 3301, are avail- able. The sensor, which is protected by an inner fixed flame arrester and an outer removable filter, is chlorine selective, with a fast response to chlorine in air. The control module is mounted in a chassis, which provides the facility for the Model 3301 to be used in conjuction with Model 4801 hydrocarbon gas modules and Model 2601 hydrogen sulphide modules to pro- vide a combined toxic and combustible gas monitoring system. General Monitors Ireland Ltd., Queens Avenue, Hurdsfield Industrial Estate, Macclesfield, Cheshire SKlO 2BN.Balances The PM series of precision balances con- sists of 9 models, covering a readability span of 0.001 to 0.1 g and weighing ranges between 0-100 g and 1-4000 g. Included are two DeltaRange models with dis- placeable fine range. The PM range of balances feature DeltaTrac, a graphic display which tells the user how much of the weighing range is used and how much is still available. The standard balance models have built-in solutions for count- ing, percentage weighing, plus - minus checkweighing, animal weighing and selection of weight units; they also have a bidirectional RS232CCL data interface. Twelve adapter consteliations are avail- able for adapting PM balances to different weighing needs.Mettler Instruments AG, CH-8606 Greifensee, Switzerland. Aerosol Mass Monitor The portable TSI Model 5500 Piezoba- lance monitor measures the true mass of respirable particles without constant cal- ibration for different aerosol materials. The use of an electrostatic precipitator ensures that all respirable aerosol par- ticles (0.01 pm to the upper respirable limit) are efficiently collected on a quartz crystal sensor which accurately detects concentration changes as small as 0.001 mg m-3 on a real-time basis. BIRAL, 6 Combe Road, Portishead, Bristol BS20 9JB. Particle Size Analyser The capability of the Microtrac particle size analyser has been extended. It now features a small volume recirculator which will not corrode, thus making it suitable for use with most common sol- vents used as carriers. Consequently the use of Microtrac has been extended, enabling it to analyse 99% of material requiring particle size measurement.In addition, it readily converts to a dry powder feed system and, alternatively, a 4 1 system for high sp. gr. (up to 18.5) metal powders, ores and alloys. The capabilities of Microtrac have been further extended by the introduction of an enhanced IBM compatible data module system which permits the automatic com- parison of samples of standard production material with particles from each new production batch. A further advantage is the enhanced capability in blending results from a standard range analyser and small particle analyser, with a readout on computer blending from 0.1 to 300 pm from two separate data disks.Leeds and Northrup Ltd., Wharfdale Road, Tyseley, Birmingham B11 2DJ. Scanning Electron Microscope The TlOO offers magnifications to ~ 1 0 0 000. Similar in cost to many advan- ced optical microscopes, it gives about 100 times the resolution at 8 nrn. The depth of field can be measured in mm rather than in pm. Jeol UK Ltd., Jeol House, Grove Park, Colindale, London NW9 OJN. Scanning Electron Microscope The SEM 525-M features a conical objec- tive lens and a motorised eucentric specimen stage, which facilitate a high degree of manipulation for specimens up to 150 mm in diameter, whilst operating under high resolution conditions. Other features include automatic focusing, auto- matic astigmatism correction and a multi- function detector system which allows several detectors to be mounted and operated in parallel.Philips Electronic Instruments, 35 McKee Drive, Mahwah, NJ 07430, USA. Nucleic Acid Extractor The Model 340A is an automated system for purification of DNA and RNA from plasmids, viruses, cells and tissues. It optimises the nucleic acid phenol extrac- tion method and processes up to 8 samples simultaneously. The 340A is designed to minimise DNA shearing and it has an automated chemical delivery system, which reduces worker contact with toxic extraction solvents. Applied Biosystems Inc., 850 Lincoln Centre Drive, Foster City, CA 94404, USA. Thermal Analysis System A new operating system has been devel- oped for the 9900 computer - thermal analyser, enabling users to customise and continually upgrade a system to meet their changing needs.The operating system combines with other hardware and28 ANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 software options to create more than 100 000 different system configurations. Du Pont (UK) Ltd., Jezz Leckenby, SPSD, Wedgwood Way, Stevenage, Hertfordshire SG1 4QN. Thermal Analysis System and Accessory A new system, EUROLAB 7, adds a DSC capability to any laboratory already in possession of the manufacturer's Model 360013700 data station. Based upon the DSC 4 differential-scanning calorimeter, EUROLAB 7 comes complete with tem- perature programmer, software and A4 plotter. A new controlled cooling access- ory is available for the maker's power- compensated DSCs. Compatible with the current Models DSC 4 and DSC 7, it can also be fitted to older Model DSC 2s.The accessory permits sub-ambient DSC oper- ation to -170 "C, using nitrogen coolant stored in a pressurised Dewar. Perkin-Elmer Ltd., Post Office Lane, Beaconsfield, Buckinghamshire HP9 1QA. Centrifuges Hettich Rotanta centrifuges are middle capacity range bench centrifuges taking from 160 x 1.5 ml reaction vials to 4 x 250 ml bottles. A complete set of accessories for cytology can also be fitted, and rotors for 8 p1 plates of 4 LKB racks, as well as most common centrifuge tube sizes, are available. Arnold R. Horwell Ltd., 73 Maygrove Road, West Hampstead, London NW6 2BF. Rotor for Benchtop Ultracentrifuge The TLA-100.3 fixed angle rotor increases the capacity of the manufactur- er's Model TL-100 ultracentrifuge, a benchtop model with a controlled temper- ature environment for ultracentrifugation of samples as small as 0.2 ml.The new rotor spins larger sample volumes in 3 ml open-top or 3.5 ml Quick-Seal tubes. A total of 6 tubes are spun at 100 000 rev min-1 or at ultracentrifugal forces to 541 000 times gravity. At top speed the TLA-100.3 has a k factor of 16.5. Beckman Ltd., Progress Road, Sands Industrial Estate, High Wycombe, Buck- inghamshire. Viscometer The DV-I1 is a digital viscometer which automatically calculates and displays vis- cosity (cP), shear stress (dyn cm-2) and % scale (Brookfield). It offers simultaneous output of all instrument parameters (limit indicators, %, CPS, SS, RPM, Model, spindle) and it is user programmable for the calculation of any spindle boundary condition.It has an eight-speed range, giving it the capability of performing rheological studies. Other features include hard copy output for connection to a recorder, printer or data logger, autozeroing, autoranging and display hold. Baird and Tatlock Ltd., P.O. Box 1, Romford, Essex RM1 1HA. Tube Furnaces Additions to the manufacturer's MTF family of precision modular tube furnaces offer the advantage of multi-zoned, pro- grammable temperature profiles to meet the needs of specific process applications. The new furnaces are available to accept reaction tubes of up to 90 mm outside diameter. In their standard form they may be supplied with maximum operational temperatures of 1700 "C. Custom-built versions are available.Lenton Thermal Designs Ltd., 12-14 Fairfield Road, Market Harborough, Leicestershire LE16 9QQ. Laboratory Information Management for Quality Control A new package is announced for LIMS. With its specification management feature the new package, QC LIMS, ensures tight control of product specifica- tion and quality control limits. It allows specifications to be generated for those situations where a product is being manu- factured for several different markets, thus requiring different analytical testing limits. The system will keep track of the specification associated with each batch of product and this, combined with the security of the system, helps the labora- tory in its compliance with good labora- tory practice. Perkin-Elmer Ltd., Post Office Lane, Beaconsfield, Buckinghamshire HP9 1QA.Dynamic Mechanical Analyser The 983 dynamic mechanical analyser (DMA) provides four modes of analysis: fixed frequency, resonant frequency, stress relaxation and creep measurement. Thus, only one instrument is needed to assess the structure, mechanical proper- ties and engineering performance of materials. DMA can determine the over- all mechanical, or viscoelastic, perfor- mance of materials such as polymers and composites. Du Pont (UK) Ltd., Jezz Leckenby, SPSD, Wedgwood Way, Stevenage, Hertfordshire SG1 4QN. Refractometer The Atago Model RX-3 automatic digital refractometer has a range from 0 to 25% Brix with a reproducibility of _+0.05%, and results are obtained within 10-30 s. The instrument is also designed to read automatically the percentage concentra- tion of the sample, the concentration range being easily set for different types of materials using a built-in converter.Measurements can be made over a range from 5 to 40 "C using a circulating thermostat, which feeds two flow lines around the prism and the photosensor. Chemlab Instruments Ltd., Horn- minster House, Upminster Road, Horn- church, Essex RMll 3XJ. Glassware Was her The Tornado I1 cleans most types of laboratory glassware, including narrow- necked items. Constructed from stainless steel, it occupies 2 m2 of floor space. Items to be cleaned are held in four 350 x 350 mm removable wire baskets, which are placed on a roller-mounted washing table. Between 200 and 2000 items can be washed in an hour depending on their size.Newsmith Stainless Ltd., Langley Mills, Roberttown, Liversedge, West Yorkshire WF15 7LF. Protective Matting Poly-Mesh is low density polyethylene protective matting, available in 18- or 24-in widths. It is flexible and can be used in laboratories to help reduce glass breakage and as a protective liner on tables, shelves, sinks, etc., to reduce scratching and chipping. Field Analytical Co. Ltd., P.O. Box 113, Weybridge, Surrey KT13 8BJ. Spectrophotometers The PU8700 Series of ultraviolet - visible scanning spectrophotometers consists of four main low to medium cost instruments based on a fixed 2 nm or variable 0.2-2 nm band width with a high resolution colour or monochrome VDU. They have no keyboard, but feature a mouse-driven user interface and a 68000-based multi- tasking operating system.The instru- ments are set up and controlled via aANALYTICAL PROCEEDINGS. JANUARY 1987, VOL 24 combination of horizontal softkeys and vertical "pop-up" menu and number-pad windows. For every parameter selection the user is supported by audio and colour coded visual prompts and error warnings and, where appropriate, on-screen help information is automatically presented. For scanning applications, the PU8700 will scan 190-900 nm, display the data graphically and produce a peak table in seconds. Pye Unicam Ltd., York Street, Cam- bridge CB12PX. X-ray Spectrometer The SRS 303 is a compact, sequential X-ray spectrometer, with an end-window tube for sample excitation. The emission stability of the end-window tube and the low control time constant of the generator permit any change in current and voltage within an analytical programme.The basic model has an internal 10-sample changer with which one sample after the other can be brought to a defined measuring posi- tion under vacuum. SRS 303 AS analysers have an internal 2-sample changer (one sample in the measuring position, the other in the stand-by position) as well as an external 72-sample changer. Features include individual sample coding, sample position selection and preferred treat- ment of high-priority samples. Siemens Ltd., Siemens House, Wind- mill Road, Sunbury on Thames, Middle- sex TW16 7HS. Automated X-ray Powder Diffrac tometer The Philips PW1800 is a fully integrated diffractometry system, designed specific- ally for the demands of routine industrial and research laboratories requiring quali- tative and quantitative powder analysis by non-specialist operators.Philips long fine-focus tubes, which pro- vide both high intensity and high resolu- tion, although a broad focus tube can be used for quantitative analysis. Automatic divergence slits allow measurements down to 1" 28, and a single-wavelength secondary monochromator gives im- proved peak to background ratios and suppression of K(3 lines. The high-effi- ciency generator consumes up to 40% less power than earlier models. Rapid scanning and slewing rates, including continuous digital scanning at up to 75" 28 per minute, give very rapid data collection. Automatic sample loading is standard, and there is an optional 20-position sample changer under microprocessor control for unattended operation.The microprocessor-based control system handles system operation and monitoring, data collection and output plus analytical processing. Compatibility with DEC 300, PDP or VAX computers enables the Philips ADP 1700 diffraction software to be employed for a wide range of analytical, data manipulation and dis- play options. The single-cabinet assembly provides effective exclusion of dust and contami- nants and makes the system ideal for application in industries such as cement production, metallurgical processing and pharmaceuticals manufacture. Philips Industrial and Electroacoustic Systems Division, 5600 MD Eindhoven, The Netherlands. Atomic Absorption Spectrophotometer The Model 5100 is a fully automated instrument, its flame, graphite furnace and autosamplers being controlled via a single interface, which also stores collec- ted data and user methods.Providing a Ph ilips P WI 800 X-ray powder d i ff ra ctometer A major feature is the new high-preci- high throughput of samples without oper- sion goniometer, designed to operate with ator intervention, it can collect new data 29 while previously stored data are reported or new methods generated. The optical system is identical to that of the makers' Model 5000: its two large gratings provide for optimum light transmission over the whole wavelength range, thus offering good limits of detection and precision. Perkin-Elmer Ltd., Post Office Lane, Beaconsfield, Buckinghamshire HP9 1QA. Remote Analyser A combination of process spectropho- tometry, fibre optics and data processing offers on-line analysis with the distance between the analyser and the point of measurement being as high as 100 m or more.Readings can be taken in corrosive and sterile environments at temperatures from -250 to +500 "C and under pressure of up to 1000 lb in-2. The ultraviolet - visible - near infrared range (23C2200 nm) is covered with an accuracy of 0.25 nm. Guided Wave International AB, Box 1264, S-252 12 Helsingborg, Sweden. Spectroscopic Software Jobin - Yvon packages contain a com- pletely integrated series of programs and special routines for the acquisition and treatment of spectroscopic data. The soft- ware allows the control of any Jobin - Yvon spectrometer, whether sine or cosine drive, in increments of A, pm, absolute and relative wave numbers.All calculations as to mechanical coverage and detector security are automatically computed before any acquisition routine is run. The packages offer complete auto- matic control of multi-channel detection, including positioning of the spectrometer, acquisition of the data and automatic calibration and linearisation of the spec- trum in desired spectral units. EDT Research, 14 Trading Estate Road, London NW10 7LU. Spectral Libraries Sadtler's full spectrum Fourier transform infrared search libraries have been expan- ded to over 100 000 spectra, with 9200 vapour phase infrared spectra and 93 000 condensed phase infrared spectra subdi- vided into over 30 different application libraries. Included among these libraries is Sadtler's Standard Spectra library of 54 000 full digital spectra of pure com- pounds.There are also over 37 000 com- mercial compounds divided into over 30 libraries such as Monomers and Poly- mers, Surface Active Agents, ATR of Polymers, Adhesives and Sealants, Com- monly Abused Drugs, Coating Chemi- cals, Flame Retardants, Inorganics, Lub- ricants, Fats, Waxes and Derivatives, Rubber Chemicals, Plasticisers, Polymer Additives and Solvents. Heyden and Son Ltd., Spectrum House, Hillview Gardens, London NW4 2JQ.30 ANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 Multi-element Analysis System The Plasmascan Model 8410 is a sequen- tial inductively coupled plasma atomic emission spectrometer which can perform rapid measurements of most elements.Features include a low argon consump- tion of typically 10 1 min-1, ease of maintenance and the Stop-flow GMK nebuliser system, which is able to operate continuously without blocking on a wide variety of sample types. The optical system uses two orders of the spectrum to cover the wavelength range 170-820 nm. Beaconsfield, Buckinghamshire HP9 1QA. Chromatography Accessories A range of Hamilton syringes, columns and a new guard assembly are available. There are 4 columns in the Hamilton range. The PRP-1 is a reversed-phase column composed of a macroporous co- polymer of styrene and divinylbenzene, which can be used over a pH range of 1-13 with up to 0.5 N buffers. The PRP-X100 is a resin based anion column designed for Labtam Plasmascan Model 8410 ICP - AES A high dispersion of 0.37 nm mm-1 is achieved with a resolution of 0.01 nm in the wavelength region of 170-310 nm.Wavelength selectability is 0.0005 nm per step. Labtam International Pty Ltd., 43 Mal- colm Road, Braeside, Victoria 3195, Australia. Utilities Package for Gas Chromatography A GC/IBM utilities package for use with the maker’s 8000 series gas chromato- graphs and IBM or IBM-compatible per- sonal computers is designed primarily for the automatic collection of raw data and reports from the chromatograph. It may be used for single chromatographic runs or for multiple runs using an automatic form of injection, e.g., AS-8300 liquid autosampler, automated gas sampling valves, ATD 50 automated thermal desorption systems or HS 101 headspace systems. The package provides the facility to process raw data and reports with programs provided by the user.Perkin-Elmer Ltd., Post Office Lane, the single column ion chromatographic separation of inorganic solvents. The HC40 and HC75 polystyrene - divinyl- benzene sulphonic acid cation exchange resin gels are formulated for the separa- tion of carbohydrates, polyols and glycols. Also available are a large range of inert miniature valves and the Howe GyroVap, which concentrates samples by evaporating the solvent under vacuum. V. A. Howe and Co. Ltd., 12-14 St. Ann’s Crescent, London SW18 2LS. Preparative Liquid Chromatography System Labomatic is a system for high perfor- mance medium pressure liquid chromato- graphy (HP - MPLC). Employing fine silica gel, it can be used for the purifica- tion of up to 100 g of chemicals.It provides a completely inert system for the purification of biologically active mole- cules. The system includes a gradient former, medium pressure piston pumps, a pulse damper, peak detectors, a spec- trophotometer, a differential refrac- tometer, fraction collectors and control instruments. Severn Analytical, 36 Brunswick Road, Gloucester GL1 1JJ. HPLC Instruments A range of instruments in modular form to make up HPLC systems includes the Model K65B autosampler, which offers precision low volume handling with a choice of pre-column reaction routines, giving sample injection from 1 to 1000 pl. Other modules include single and dual plunger pumps, a gradient controller, a variable ultraviolet detector, column heaters - coolers, a buffer switching module and a post column reactor.The K25D single plunger pump is designed for use with conventional and microbore columns, while the K35D dual plunger pump is a digitally controlled device also designed for such columns. The K45 gradient computer is capable of control- ling two pumps in addition to six external devices. The K95 variable wavelength ultraviolet detector offers high sensitivity and freedom from refractive index effects. ETP-Kortec Pty Ltd., 31 Hope Street, Ermington NSW 2115, Australia. HPLC Column Packing Spherisorb ODs-2 is a bonded phase material with a carbon content (12% m/m) higher than that of the maker’s Spherisorb ODs-1 (7% mlm), and in contrast with the latter it is fully capped, making it an especially suitable reversed phase material for the separation of amino acids, aromatic compounds such as benzenes, amines and phenols, barbitu- rates and catecholamines.It may be used in ion pair reversed phase chromato- Chrompack UK Ltd., Unit 4, Indescon graphy * Court, Millharbour, London E l 4 9TN. HPLC Column for Protein - Peptide Applications Ultrapore-C8 is a column that is especially suitable for the isolation and purification of biomolecules in protein structural studies. Surface characteristics of the column are enhanced by exhaustive end- capping, thus ensuring minimal non- specific interaction and high mass recovery. Beckman Ltd., Progress Road, Sands Industrial Estate. High Wycombe, Buck- inghamshire. System for Protein Analysis Using the established rate nephelometric method, the Array protein analyser is complemented by 18 specific protein test kits and requires no incubation, off-line sample preparation or out-of-range repeats. A single calibration is required every 2 weeks or so.The operator inter- face can be selectively programmed on installation to meet individual require-ANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 31 ments, including specific test panels and result units. Daily operation then needs only random selection from the user- defined menu. Beckman Ltd., Progress Road, Sands Industrial Estate, High Wycombe, Buck- inghamshire. Software for Chromatography BALANCE and BARCODE are packages for use with the makers’ IBM PC based chromatography data system; they allow the automatic entry of balance and bar- code data.XTRA TALK is a data communi- cations package for the makers’ Model 4430X multi-instrument system for chro- matography data handling in analytical chemistry applications; the package pro- vides bi-directional data communications between any Model 4430X data system and other Series 4400X systems (based on the HP Series 9000), HP minicomputers (HP 1000 and HP 3000) and personal computers (IBM, PC, HP 150 and HP Touchscreen). XYPLOT and ~DPLOT pro- grams complement the makers’ HP 9000- based chromatography work stations, allowing direct output of chromatography files from the work station to X - Y plotting devices. Both operate as auxiliary programs to the makers’ XTRA CHROM data acquisition, processing and post-run soft- ware, and both are compatible with the IEEE-488 line of 2-pen, 6-pen and 8-pen X - Y plotters from Hewlett Packard.XYPLOT allows the plotting of up to 8 chromatograms simultaneously on an X - Y plotter, with the individual selection by the operator of scaling options along with overlay or stacked modes. ~DPLOT allows plotting of up to 16 chromatograms with user-selectable offset and angle offsets. A “hidden chromatogram” feature provides three-dimensional simulation of the data files so that users can examine multiple data files with respect to time of measure- ment. Both XYPLOT and ~ D P L O T have a graphic editing feature allowing the user to re-scale and proportion data on the CRT using cursor graphics. Nelson Analytical Inc., 10061 Bubb Road, Cupertino, CA 95014, USA. Electrophoresis System A new budget system the Electro-4, includes a transilluminator, a gel tank, a power supply and a camera. It is able to carry out electrophoresis, visualisation and photodocumentation at one station using only 2 ft2 of bench space.Ultra-Violet Products, Science Park, Milton Road, Cambridge CB4 4HF. Chemical Oxygen Demand Analyser The Radiometer DTS895 COD analyser is a modular system consisting of a titra- tor, an automatic burette, a printer and a sample changer, which is equipped with a removable turntable. The measuring elec- trode is a combined platinum - mer- cury(1) sulphate electrode. The DTS895 can titrate unattended up to 20 samples in the narrow digestion tubes. V. A. Howe and Co. Ltd., 12-14 St. Ann’s Crescent, London SW18 2LS. pH Meters The Models 20 and 21 “PHI” meters have been tested and proclaimed “intrinsically safe for Class 1, Division 1, Groups A , B, C and D hazardous locations” in the USA.Both meters feature micropro- cessor control for unattended measure- ment in potentially hazardous environ- ments and both have display, error and out-of-temperature-range flags, constant temperature display and temperature computation with or without an automatic temperature compensation probe. They feature auto reads, auto finds, automatic temperature compensation, slope indica- tion and computation, automatic stan- dardisation, stability detection, calibra- tion and recognition of 5 buffers. Both measure pH in the &14 range, with resolution to 0.01, and temperature in the range 0-99.9 “C, with resolution to 0.1 “C.The pH1 21 measures mV with a resolution to 1.0. Beckman Ltd., Progress Road, Sands Industrial Estate, High Wycombe, Buck- inghamshire. pH Electrodes Two refillable models have been added to the maker’s range of unbreakable epoxy- bodied pH electrodes. Called the RX Series, they can be filled with a free- flowing KC1 solution. The models 91-56 US and 91-56 BN have a pH range of 0-14, with a relative accuracy of t-0.02. The 91-56 US is equipped with US-stan- dard and pin-tip connectors; the 91-56 BN has a BNC connector. MSE Scientific Instruments, Sussex Manor Park, Gatwick Road, Crawley, Sussex RHlO 2QQ. pH Electrode Switchbox The Orion Research Model 607 electrode switchbox allows up to 7 separate elec- trode inputs to be linked to a single pWISE meter. Suitable for use with most pWISE meters, the Model 607 can either measure one parameter in 6 different samples, using the same electrode on each channel, or split one sample and analyse several parameters by placing a different electrode on each channel.MSE Scientific Instruments, Sussex Manor Park, Gatwick Road, Crawley, Sussex RHlO 2QQ. Solution for Ammonia Analysis Orion Research have introduced a pH- adjusting ISA solution for ammonia analysis. It quickly adjusts the pH of a sample, thus eliminating the need to take pH measurements and adjusts the am- monia sample accordingly. MSE Scientific Instruments, Sussex Manor Park, Gatwick Road, Crawley, Sussex RHlO 2QQ. Nep helome ter The analyte nephelometer uses fibre optics to transmit light in the near infrared spectrum and to receive light scattered back at 180” by particles in suspension, enabling direct turbidity measurements to be made in liquids ranging from drinking water to whole milk simply by inserting the probe in the undiluted sample.BWD Precision Instruments Pty Ltd., 5 Dunlop Road, Mulgrave, Victoria 3170, Australia. Surface Tension Meter The meter makes use of a thin plate suspended from a precision strain gauge and partially immersed in a liquid, where it is subjected to a downward force due to the surface tension of the liquid. The resulting electrical output is then dis- played digitally as a direct readout of surface tension in mN m-1. BWD Precision Instruments Pty Ltd., 5 Dunlop Road, Mulgrave, Victoria 3170, Australia. Sample Changer The ST20 is a peripheral unit for the maker’s DL20 CompactTitrator, in com- bination with which it can automate entire analysis sequences in routine operation: from the dilution of samples via dispens- ing of auxiliary reagents, up to and including the actual titration, computa- tion of the results and rinsing of the electrodes.The system calibrates the elec- trodes automatically and these can be conditioned automatically in accordance with selectable parameters and with the use of any definable reagents. Mettler Instrumente AG, CH-8606 Greifensee, Switzerland. Software for Thermal Analysis TA70 Graphware plots all data and results of thermoanalytical measurements graphically on a computer display screen. Up to 4 thermoanalytical graphs can be depicted simultaneously and compared with one another, the graphs being super- imposed or each in its own window, TA70 Graphware is designed for use with the maker’s TA3000 thermal analysis system and an IBM personal computer.Mettler Instrumente AG, CH-8606 Greifensee, Switzerland. ANAPRODECREV02/0132 ANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 Trace Metals Analyser Designed for use in the field, the voltam- meter was developed after several years of research by CSIRO. It can be operated from its own batteries as well as from a 12-V or 24-V supply in a vehicle or from the mains, and it is capable of analysing 10 metals down to the p.p.b. level, including copper, lead, zinc, cadmium, arsenic and gold. The solution analysis is micro- processor controlled and the results are displayed digitally in p.p.b.if a standard calibration has previously been carried out. For some elements there is the capability for simultaneous analysis and for all elements a wide linearity range. Chemtronics Pty Ltd., Unit 2, Tech Centre, Brodie Hall Drive, Bentley, WA 6102, Australia. Iron Analyser Ferrochem 11, which employs coulometry for measuring trace levels of iron, pro- vides digital display serum-iron analyses in only 30 s using samples of only 25-pl size. Severn Analytical, 36 Brunswick Road, Gloucester GL1 1JJ. Syringe Filling Machine The device facilitates automatic filling of twin syringes at the rate of 1000 h-1 by one operator. Capable of use with differ- ent types of syringes, it consists of 2 units. The first allows automatic filling of free flowing liquid from 1 to 3 ml as standard, while volumes to 50 ml can be accommo- dated.The secondary unit is connected to the main unit with plastic air hoses and houses the pneumatic valves, speed con- trol and adjustment. Arthur Webster Pty Ltd., 226 Windsor Road, Northmead, New South Wales 2152, Australia. Titrator The Radiometer TitraLab series of titra- tion systems perform complex titration procedures for single as well as batch samples, unattended switching automatic- ally between multiple reagents, titrants, electrodes and titration procedures, according to selected programme. Titra- Lab systems are programmable, with memory space for up to 60 user-defined methods, which can be selected from four different titration techniques, pH-stat work and pH - mV measurement, or linked together with automatic switch between reagents.For method development a pilot titration mode helps the user by suggest- ing suitable titration techniques including parameter settings. The formula library, with 21 formulae, assists with the calcula- tion of sample concentration. The series consists of several systems to fit various automation needs. V. A. Howe and Co. Ltd., 12-14 St. Ann's Crescent, London SW18 2LS. Vacuum Pumps The DD range of direct double stage high vacuum pumps all feature the VACPAK interchangeable vacuum cartridge, which ensures that all moving parts are inter- changeable; the cartridge can be replaced without disturbing critical vacuum set- tings. The DD covers 30,60, 125 and 250 1 min- and the pumps feature built-in gas ballast, oil pump, an automatic vent to prevent suck-back, low oil consumption, TEFC electric motor with built-in over- load and a carry handle.Javac Pty Ltd., 54 Rushdale Street, Knoxfield, Victoria 3180, Australia. Platinum Electrodes A custom design service is announced for thick film platinum electrodes. Thick film platinum can be high-temperature fused on to flat alumina substrates of simple or complex shape or it is available in an ultraviolet cured form for use on materials unsuitable for high temperature applica- tions. The possibility of providing intri- cate electrode designs opens up new opportunities in diverse applications, such as chemistry, hygrometry, trans- cutaneous and surface skin measure- ments, animal husbandry, etc. Matthey Electronics, Burslem, Stoke on Trent ST6 3AT. Radiation Shields Naigene acrylic beta radiation shields are designed to provide maximum shielding during procedures which require the handling of commonly used beta-emitting isotopes on the laboratory bench.The new family of shields, which cannot shield Radiometer Titralub titration system against secondary X-rays or gamma radia- tion, includes a free-standing Benchtop Beta Shield, Benchtop Beta Waste Con- tainers, Beta Block Test Tube Racks, Microcentrifuge Tube Beta Racks and a Beta Storage Box. Nalge Co., Division of Sybron Corpor- ation, 75 Panorama Creek Drive, P.O. Box 365, Rochester, NY 14602, USA. Liquid Circulator The Haake Model HT400 is a totally enclosed circulator designed for use between 70 and 350 "C. The liquid reser- voir is enclosed and not available for immersion of samples, thus avoiding con- tact between hot bath liquid and oxygen.The HT400 is suitable for continuous unsupervised operation, conforming to the German DIN standard 12879 Class 2. Gallenkamp, Belton Road West, Loughbourough, Leicestershire LE11 OTR. Application Packages for Balances The redesigned series of Mettler Pacs has appeared on the market, together with the maker's PM range of balances, which feature the DeltaTrac graphic display. The Pacs are available in English, Ger- man, French, Spanish and Italian. All calculations and conversions, and logging if a printer is available, are carried out automatically. The LabPac simplifies for- mulating tasks, calculating net total at the touch of a key. PharmaPac has the same function and can handle many statistical operations as well.ProPac makes it pos- sible to count with fixed or variable reference quantities. CountPac meets counting requirements, StatPac optimises filling amount checkweighing operation, and DataPac is able to communicate with a computer. Mettler Instrumente AG, CH-8606 Greifensee . Switzerland. Radiochemical Fume Cupboards The general specification of the fume cupboards is built to at least Class C standard, although up to Class A situa- tions can easily be met, and it includes an extraction rate equivalent to an entry velocity of 0.5 m s-1 maximum working opening. Where users require entry velo- cities up to 1.0 m s-1 the duct outlet size can be adjusted. Internal linings are provided in the form of one-piece, fully welded PVC or stainless steel, and lead sheet can be built below the worktop to offer extra protection against ionising radiation.A discharge tank can be fitted if needed. Hoare Laboratory Engineering Ltd., 3 Victoria Road, Sevenoaks, Kent TM13 1YB. Lamp Crusher The FSL lamp crusher provides a solution to the problem of disposal of spent fluorescent tubes. Capable of acceptingANALYTICAL PROCEEDINGS, JANUARY 1987. VOL 24 33 up to 20 fluorescent tubes up to 8 f t long, or their equivalent, in any one loading. the crusher is mounted on an outside wall and connection to a mains water supply allows the lamps to be sprayed during crushing to dampen dust and vapour and to neutralise the fire risk from sodium. Balcan Engineering, Woodhall Spa, Lincolnshire LNlO 6RW.Recorder The Series 2000 offers complete inte- grated measurement capability, the measurement modules currently available permitting direct recording of pH, con- ductivity, pressure, temperature, current changes, dissolved oxygen, humidity and strain. A "breadboard" module kit can be tailored to the user's own design function. Featured are three active pens, electric pen lift, easy paper installation, tilt out locking platen, rapid paper advance, remote chart control, 0.5 s response time and 1-5 V signal for re-transmission to other instruments. The Series 2000 main- frames are available in up to 3 channel configurations with 12 chart speeds. Linear Instruments Ireland, P.O. Box 3, Bay 89, Shannon Industrial Estate, County Clare, Ireland. Scanning Proton Microprobe Developed at the Micro Analytical Research Centre at the University of Melbourne, the microprobe system can be used for ultrasensitive microanalysis in many areas of science and industry.Similar in concept to a scanning electron microscope, it focuses a beam of protons or other nuclei. The beam of particles must be provided by a low energy charged particle accelerator. ATICCA, Office of Research, Univer- sity of Melbourne, Parkville, Victoria 3052, Australia. Polarising Microscope The POLYVAR-POL is a wide field polarising microscope for use with both incident and transmitted light. Its rotary stage facilitates specimen orientation, and a Bertrand module allows rapid inter- change between techniques without optics change or loss of image definition.The modular design of the POLYVAR- POL enables optomechanical com- ponents to be inserted between the objec- tives and the eyepieces without restricting the field of view or altering the magnifica- tion. By sliding the Bertrand module into position a single crystal can be located under orthoscopy and then examined under binocular conoscopy without changing the eyepieces. The POLYVAR- POL features an integrated camera system. Reichert-Jung Ltd., 820 Yeovil Road, Slough SL1 4JB. Clean Air Cabinets Horizontal laminar flow clean air cabinets and work stations are now available on only two week's delivery. Standard widths range from 900 to 1800 mm, free-standing or bench mounted. All units comply with Class 1 of BS 5295. Envair (UK) Ltd., York Avenue, Haslingden, Lancashire BB4 4HX.Software Spectra-Physics SP4270190 and SP4290 integrators can now be linked with IBM compatible computers through new Link- up software. Linkup is an Apricot com- puter program offerjng terminal emula- tion plus file and results storage for the SP4270 integrators. Quadrant Scientific Ltd., 36 Brunswick Road, Gloucester GL1 1JJ. Literature A brochure describes a range of high sensitivity, static vacuum mass spec- trometers for noble gas analysis. The VG 1200C is a standard mass spectrometer, enabling the isotopic analysis of all noble gases with some limitations on helium only. The VG 1200s is an argon dedicated instrument using the Baur - Signer ion source. The VG 5400 has been developed without compromise for the determina- tion of the 3HePHe ratios and is suitable for the measurement of all other noble gases.A document has also been pub- lished summarising the state of the art of the technique of inductively coupled plasma mass spectrometry, with reference to the PlasmaQuad instrument, on which a brochure is also available. VG Isotopes Ltd., Ion Path, Road Three, Winsford, Cheshire CW7 3BX. A catalogue describes a range of access- ories for infrared - visible - ultraviolet spectroscopy. It includes a wide range of equipment: instruments for optical spec- troscopy, crystals for optical spectro- scopy, attachments for reflection - trans- mission and other accessories and com- ponents. It also includes a list of other publications. Harrick Scientific Corporation, 88 Broadway, Box 351. Ossining, NY 10562, USA.A Handbook of Sample Preparation and Handling describes a range of spectro- scopic accessories and sample preparation equipment, as well as offering informa- tion on techniques and giving useful hints. The makers are extending their line of disposable X-ray fluorescence cells and window films, now offering semi-micro cells to hold small environmentally sensi- tive samples, double ended cells for liquid, powder or slurry samples, and window films of various thicknesses and types. Glen Creston Instruments Ltd., 16 Dalston Gardens, Stanmore, Middlesex HA7 1DA. A catalogue on low flow measurement for chromatography and other associated analytical techniques deals with purgemeters, a low flow armoured flow- meter for dealing with high pressure and fluids that are difficult to handle, fine needle valves, flow controllers, extremely low flow pressure regulators, electrically operated control valves for liquids and gases, and a number of other related topics.Field Analytical Co. Ltd., P.O. Box 113, Weybridge, Surrey KT13 8BJ. A series of chromatography application notes are available. They describe the GC and HPLC analysis of a large number of components, such as hydrocarbons, al- cohols, esters, halogenated compounds and amines in synthetic as well as life samples. Dedicated techniques, such as thermal desorption, cold trap injection and purge and trap injection are also shown. Chrompack UK Ltd., Unit 4, Indescon Court, Millharbour, London E l 4 9TN. A brochure describes the Lee Scientific Model 501 SFC system for supercritical fluid chromatography.Eleven chromato- grams provide an understanding of the system's sensitivity. Data are shown for erythromycin, cholesterol, carbon black, pesticides and a polyol surfactant. The brochure also discusses the wide range of capillary columns, and LC and GC detec- tors compatible with the new system, which is available in the UK from Dionex (UK) Ltd., Eelmoor Road, Farnborough, Hampshire GU14 7QN. Lee Scientific. 4426 South Century Drive, Salt Lake City, UT 84123-2513, USA. An application sheet giving full perfor- mance figures describes the method used by Dr. David Batty and Miss Sima Paz- ouki of the Department of Biochemical Medicine at Ninewells Hospital, Dundee, for the analysis of plasma fatty acids with a Philips analytical gradient liquid chro- matograph. Using a 3 ym (C,) column and fluorescence detection they produced a complete profile on anthrylmethyl ester derivatives of a whole series of fatty acids, ranging from C1+" to Cz0+ Pye Unicam Ltd., York Street, Cam- bridge CB1 2PX. A leaflet is available on the Digichem 3000 process chemical analyser.This microprocessor controlled instrument, using multiple reagents and various detec- tors, can perform a wide variety of titri- metric, colorimetric and ion selective measurements on aqueous and organic solutions. Ionics, 10 Statham Avenue, Lymm, Cheshire WA13 9NH.34 ANALYTICAL PROCEEDINGS. JANUARY 1987, VOL 24 A disposable containers catalogue con- tains information on plastic screw cap sample containers, pipettes, Petri dishes and other laboratory consumables. Medfor Products, 15 King’s Road, Fleet, Hampshire GU13 9AA.Leaflets give details of a wide range of laboratory skills training courses, which are available in two formats: videotape and slide - tape. The courses, which are presented with scripts, visuals and narra- tions, cover various aspects of subjects such as atomic absorption, chromato- graphy, electrochemistry, electrophor- esis, enzymology, haematology , immuno- assay and spectroscopy. Savant, P.O. Box 3670, Fullerton, CA 92634, USA. A technical report describes recent devel- opments in the application of the Plasma Quad inductively coupled plasma mass spectrometer. Results show that detec- tion limits (sub ng ml-1) for most ele- ments are similar to those obtained with aqueous sample introduction and can be routinely achieved with minimal spectral interference. The studies described included full mass range semi-quantita- tive and restricted mass range quantita- tive analysis. They showed that the use of ICP - MS for the analysis of trace ele- ments in an organic matrix represents a significant advance in this type of study. VG Isotopes Ltd., Ion Path, Road Three, Winsford, Cheshire CW7 3BX. A brochure describes the VXR Series of nuclear magnetic resonance spectromet- ers. This new series of superconducting Fourier transform instruments at 100, 200, 300, 400 and 500 MHz offers flexi- bility in research applications from biotechnology to synthetic materials. Varian Instrument Group, 28 Manor Road, Walton on Thames, Surrey KT12 2QF. A leaflet, “Optimise Sample Resolution with Pierce HRGC Columns,” describes a range of fused silica capillary gas chromat- ography columns. A complete selection of columns, bonded phase or standard wall coated open tubular columns, each with a wide range of stationary phases and film thicknesses, is offered. Pierce UK Ltd., 36 Clifton Road. Cambridge CB1 4ZR. The MEGABORE Column Update Bro- chure contains information on new appli- cations and new columns. Chromato- grams of alkaloids, amphetamines, barbi- turates, anticonvulsants and other drugs illustrate column sensitivity and reduced analysis time. The new DB-624 column is designed for analysing purgeable organ- ics, as specified by EPA methods 601, 602, 604, 501, 502 and 524. Chromato- grams show ethylene dibromide and purgeable hydrocarbons and aromatics, all peaks resolved in a single 25-min run without cryogenic cooling. J & W Scientific Inc., 91 Blue Ravine Road, Folsom, California 95630, USA. A brochure describes a recently launched range of high-temperature ovens operat- ing at 400,500 and 400 “C with a choice of five chamber sizes. A data sheet describes a range of small chamber furnaces for use in laboratories and in the heat treatment of small components: the maximum oper- ating temperature of these units is 1200 “C. Carbolite Furnaces Ltd., Bamford Mill. Bamford, Sheffield.

ISSN:0144-557X    

DOI:10.1039/AP9872400025

出版商:RSC    

年代:1987

数据来源: RSC

摘要:

34 ANALYTICAL PROCEEDINGS. JANUARY 1987, VOL 24 Conferences and Meetings Chromatography in the Analysis of Water February 4, 1987, London The Chromatography and Electrophore- sis Group of the Analytical Division and the Water Chemistry Forum of the RSC, together with the Chromatographic Society, will hold a symposium in the Scientific Societies’ Lecture Theatre, New Burlington Place, London, W. 1. The lectures given will be as follows: “Water for Chromatography,” by S. Sullivan; “Micellular Chromatography of Anions,” by F. G. P. Mullins; “Ion Chromato- graphic Analysis of Waters in the Central Electricity Generating Board,’’ by G. Goodfellow; “A Silicone Rubber Post- suppressor Device for Use in Ion Chro- matography,” by M. R. Cave; “Monitor- ing of Phenol in River Water by Auto- mated HPLC,” by P.J. Rennie; “Analysis of Organics in Sea Water,” by E. R. Adlard; “Coupled Chromatography - Atomic Absorption Spectrometry for Trace Metal Speciation in Water,” by L. Ebdon; and “Problems Encountered in Installing and Commissioning GC - MS in a Major Water Laboratory,” by a Mem- ber of the Welsh Water Authority. For further information contact Dr. D. Simpson, Analysis for Industry, Factories 2/3, Bosworth House, High Street, Thorpe-le-Soken, Essex C016 OEA. New Techniques for the Forensic and Industrial Analyst February 14, 1987, London A Joint Meeting of the Chromatography and Electrophoresis Group of the Analy- tical Division and the Eastern England Region of the Industrial Division of the RSC, together with the Forensic Science Society and the Association of Consulting Scientists, will take place at St.John’s Hall, 15 Monck Street, London, S.W.l. The meeting will provide an opportunity for the presentation of short (15-min) papers in addition to the following invited papers: ‘‘IT - IR Microscopy,” by C. Curry; “Optical Microscopy of Poly- mers,” by D. Helmsley; “Analysis of Plasticisers in Plastic Packaging,” by J. Gilbert; and “The Determination of Synthetic Colours in Foodstuffs.” by N. Boley. For further information (or if you wish to present a paper) contact Miss P. Hamer or Mrs. J. Gilburt at the Metropolitan Police Forensic Science Laboratory, 109 Lambeth Road, London SE1 7LP. Biotechnology in Animal Health: the Dynamics of the Marketplace February 23-24, 1987, Washington, DC, USA Major changes are taking place in the animal health field.Genetically engineered vaccines, pharmaceuticals and new diagnostic systems are making a significant impact on veterinary work. For example, the commercial market for veterinary diagnostic reagents for infec- tious diseases is expected to triple between 1985 and 1990. A conference is announced that will cover this area in depth. The two-day meeting will take place in Washington. DC, at the Omni- Shoreham Hotel. A group of prominent speakers from industry, government and academia will gather to discuss the central issues of the impact of biotechnology on the animal health business. Markets, technology, regulatory issues and the newest products from research and development will beANALYTICAL PROCEEDINGS.JANUARY 1987. VOL 24 35 among the subjects addressed. Among the key speakers will be David Shaw of Agritech Systems, James W. Glosser of the USDA and Harris A. Lewin of the University of Illinois. For further information about the con- tents of the conference or about registra- tion, contact Robert S. First Inc., 707 Westchester Avenue, White Plains, NY 10604, USA. Electroanalysis and Sensors in Biomed- ical, Environmental and Industrial Sciences April 6-9, 1987, UWlST, Cardijf The Electroanalytical Group of the Analytical Division of the Royal Society of Chemistry is organising an Interna- tional Symposium at UWIST, Cardiff. The programme will be on aspects of electroanalysis, including sensors, relat- ing to biomedical, environmental and industrial sciences.Emphasis will be laid on methodology and applications of the various electroanalytical methods, espe- cially regarding use of the various mem- brane and membrane-clad electrodes, gas sensors, biosensors, etc. Principles and methods of teaching electroanalysis to practitioners in the theme areas will also be included. Specially invited lecturers will deliver Plenary Lectures, and these will be sup- plemented by contributed papers as lec- tures or posters. The Plenary Lecturers include: A. G. Fogg (University of Lough borough) on ”Electrochemical Pre- treatment and Chemical Modification of Electrodes”; G. G. Guilbault (University of New Orleans, USA) on a theme related to “Enzymes and Biosensors”; W. R. Heineman (University of Cincinnati, USA) on “Immunoassay With Electro- chemical Detection”; J. Janata (Utah, USA) on “Integrated Solid State Electro- chemical Sensors”; H.J. Marsoner (Graz, Austria) on “Quality Control and Stan- dardisations for ISE Analysis in Clinical Practice”; C. Tran Minh (St. Etienne, France) on “Biosensors for Electrochem- ical Analysis of Enzyme Inhibitors”; M. Otto (Freiberg, GDR) on “Chemometric Principles in Electrochemical Analysis”; E. Pungor (Budapest, Hungary) on “Edu- cation and Training of Non-chemist Users of Electrochemical Sensors”; and J. Wang (New Mexico, USA) on “Recent Advances in Adsorptive Stripping Vol- tammetry.” For further information contact The Secretary, Short Courses Section, UWIST, P.O. Box 68, Cardiff CF1 3XA. Ion Exchange Conference April 13-16, 1987, Wrexham The First International Conference on Ion Exchange Processes, ION-EX ’87, will be held at the North East Wales Institute, Wrexham, Clwyd.Four areas will be discussed: Inorganic Ion Analysis, Organic and Base Analysis, Theory of Ion Exchange and Novel Developments, and Industrial Ion Exchange Procedures including Effluent Treatment. Over 35 papers are to be read by authors from 10 countries; a poster presentation and exhi- bition will also take place. Delegate registration forms can be obtained from the Organisers, Ion-Ex ’87, Research Division, The North East Wales Institute, Deeside, Clwyd CH5 4BR. International LIMS Meeting June 23-25, 1987, Pittsburgh, PA, USA The First International Laboratory Infor- mation Management Systems (LIMS) Meeting will be held at the Westin- William Penn Hotel. The meeting is being organised by a volunteer committee Chaired by Dr. Gerst A. Gibbon of the US Department of Energy’s Pittsburgh Energy Technology Center. It will be the first single topic meeting held to discuss all facets of LIMS, including design, specification, construction or acquisition , installation and evaluation. The meeting will also offer laboratory managers and scientists considering the construction or purchase of a LIMS an excellent oppor- tunity to meet with experienced users and a wide range of vendors and their tech- nical staff personnel. Papers are solicited from both analy- tical and clinical laboratories addressing all areas of general interest. Preference will be given to papers discussing actual experience in the acquisition and use of LIMS. Authors should send preliminary abstracts to Dr. Harmon Brown, FILM Program Chairman, Nelson Analytical, 10061 Bubb Road, Cupertino, CA 95014, USA. All other inquiries should be addressed to: FILM, P.O. Box 18375, Pittsburgh, PA 15236, USA.

ISSN:0144-557X    

DOI:10.1039/AP9872400034

出版商:RSC    

年代:1987

数据来源: RSC

摘要:

ANALYTICAL PROCEEDINGS. JANUARY 1987. VOL 24 35 Courses 24th Annual Short Summer Course in X-ray Spectrometry June 1-5, June 8-12 arid August 17-21, 1987, Albany, NY, U S A The 24th annual short course in Modern X-ray Spectrometry will be offered at the State University of New York at Albany. The course is an integrated tutorial, start- ing from fundamentals, advancing by careful degrees to the latest developments in mathematical and computer techniques and emphasising practical applications. Both weeks illustrate and employ wavelength and energy dispersive methods equally. Equal time is devoted to lectures, laboratories and problem- solving workshops. The first week covers fundamentals, principles and practice and prepares students to carry out any conceivable type of chemical analysis.The second week further develops principles and practice and emphasises the several techniques for absorption-enhancement corrections, including mathematical and computer. The third, August, week is devoted com- pletely to mathematical and computer methods for matrix correction. The tui- tion fees will be: $1100.00 each week, Sessions I and 11, and $1200.00, Session 111, payable in US dollars drawn on a US bank. To register and for further information contact Professor Henry Chessin, State University of New York at Albany, Department of Physics, 1400 Washington Avenue, Albany, NY 12222, USA. 24th Annual Short Summer Course in X-ray Powder Diffraction June 15-19 and June 22-26,1987, Albany, NY, USA The 24th two-week short summer course in Modern X-ray Powder Diffraction will be offered at the State University of New York at Albany. The course is an inte- grated tutorial, beginning with fundamen- tals and developing the entire practice and theory up to the latest advances and techniques. The first week stresses fun- damentals. The second week places much emphasis on quantitative methods and prepares the student to carry out any kind of quantitative analysis. Mathematical and computer calculations and diffrac- tometer automation are given significant attention. Registration is made by payment of tuition fee of $1100.00 for each week, payable in US dollars drawn on a US bank. To register and for further information please communicate with Professor Henry Chessin, State University of New York at Albany, 1400 Washington Ave- nue, Albany, NY 12222, USA.

ISSN:0144-557X    

DOI:10.1039/AP9872400035

出版商:RSC    

年代:1987

数据来源: RSC

摘要:

36 ANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 Analytical Division Diary JANUARY Wednesday, 21st, 6.30 p.m.: London South East Region and Microchemical Methods Group. Quality Assurance. Speaker: C. A. Johnson. Savoy Tavern, Savoy Street, London, W.C.2. There are no registration formalities. Contact: Mr. P. R. W. Baker, 55 Braemar Gardens, West Wickham, Kent BR4 OJN. (Tel. 01-777-1225). Wednesday, 21st: Guildford South East Region, jointly with the Downland Section of the Theophilus Redwood Lecture by A. M. Ure. University of Surrey, Guildford. Contact: Dr. A. H. Andrews, Beecham Pharmaceuticals, Clarendon Road, Worthing, Sussex BN14 8QH. (Tel. RSC. 0903-39900, EX. 428). Thursday, 22nd, 4 p.m.: Glasgow Scottish Region, jointly with the Glasgow and West of Scotland Section of the RSC and the Andersonian Society.New Electrochemical Sensors. Speaker: Professor J. Albery. Department of Chemistry, Strathclyde University, Cathe- dral Street, Glasgow. Contact: Dr. J. M. Warren, Department of Biochemistry, Royal Infirmary, Glasgow G4 OSF. (Tel. 041-552-3535, Ex. 428815108). Thursday, 22nd: London Section of the RSC. South East Region, jointly with the Chilterns and Middlesex Theophilus Redwood Lecture by A. M. Ure. Imperial College, South Kensington, London, S. W. 7 . Contact: Dr. A. H. Andrews, Beecham Pharmaceuticals, Clarendon Road, Worthing, Sussex BN14 8QH. (Tel. 0903-39900, EX. 428). Thursday, 29th, 5.15 p.m.: Cardiff Western Region: Annual General Meeting. Optimisation and Pattern Recognition Speaker: K. W. C. Burton. UWIST, Cardiff. Contact: Mr.F. W. Sweeting, Wessex Water Authority, Water Management Unit, Mead Lane, Saltford, Bristol BS18 3ER. (Tel. 02217-3692, Ex. 144). Thursday, 29th: Belfast Northern Ireland Region. Breath Testing for Alcohol. Queen’s University, Belfast. Contact: Mr. W. J . Swindall, Department of Chemistry, David Keir Building, Queen’s University, Belfast BT9 5AG. (Tel. 0232-661111, Ex. 4428). FEBRUARY Wednesday, 4th, 9.30 a.m.: London Chromatography and Electrophoresis Group, jointly with the Chromatographic Society and in association with the RSC Water Chemistry Forum. Chromatography in the Analysis of Water. “Water for Chromatography,” by S. Sullivan. “Micellar Chromatography of Anions,” by F. G . P. Mullins. “Ion Chromatographic Analysis of Waters in the Central Electricity “A Silicone Rubber Post-suppressor Device for Use in Ion “Monitoring of Phenol in River Water by Automated HPLC,” by “Analysis of Organics in Sea Water,” by E.R . Adlard. “Coupled ChromatographyiAAS for Trace Metal Speciation in Water,” by L. C. Ebdon. “Problems Encountered in Installing and Commissioning GC - MS in a Major Water Laboratory,” by a member of the Welsh Water Authority. Scientific Societies Lecture Theatre, New Burlington Place, off Savile Row, London W. 1. Registration is necessary. Cost &27 to RSC and Chromato- graphic Society members, and f40 to non-members. Contact: Dr. D. Simpson, Analysis for Industry, Factories 2/3, Bosworth House, High Street, Thorpe-le-Soken, Essex C016 OEA. (Tel. 0255-861714). Generating Board,” by G.Goodfellow. Chromatography,” by M. R . Cave. P. J . Rennie. Tuesday, loth, 10.15 a.m.: Stevenage East Anglia Region. GLP and Quality Assurance. “GLP and QA in the Modern Analytical Laboratory: An Over- view,” by D. C. M. Squirrell. “The UK GLP Compliance Programme,” by D. Moore. “The Role of the Quality Assurance Unit.” by H. R. Roderick. “GLP Considerations of Computerisation in the Analytical Labora- tory,” speaker to be announced. “Some Aspects of GLP in a Pharmaceutical Analysis Laboratory.” by A. Stavrou. “The Role of the BCR Programme in the Quality Assurance of Foods” by P. Wagstaffe. Warren Spring Laboratory, Gunnels Wood Road, Steven- age, Hertfordshire. Registration is necessary. Cost f2.5 to RSC members, f40 to non-members and 210 to student and retired members.Contact: Mr. P. R. Brawn, Unilever Research, Colworth Laboratory, Sharnbrook, Bedfordshire MK44 1LQ. (Tel. 0234-22201 1). Saturday, 14th, 9.45 a.m.: London Chromatography and Electrophoresis Group, jointly with the Eastern England Region of ID, the Forensic Science Society and the Association of Consulting Scientists. New Techniques for the Forensic and Industrial Analyst. “FT - IR Microscopy,” by C. Curry. “Optical Microscopy of Polymers,’‘ by D. Helmsley. “Analysis of Plasticisers in Plastic Packaging.” by J . Gilbert. “The Determination of Synthetic Colours on Foodstuffs,” by Additional short papers will also be prcscnted. St. John’s Hall, 15 Monck Street, London SWlP 2BJ. Registration is necessary. Cost f 3 to members of the [continued inside back cover] N .Boley. organising bodies and &8 to non-members.ANALYTICAL PROCEEDINGS, JANUARY 1987, VOL 24 ... 111 Analytical Division Diary, continued February, continued Contact: Mrs. J. Gilburt, Metropolitan Police Forensic Science Laboratory, 109 Lambeth Road, London SE17LP. Monday, 16th, 7 p.m.: London Particle Characterisation Group. 21st Birthday Meeting. “Estimation of the Surface Area of Fine Particles,” by “Size Analysis by Optical Microscopy,” by A. Rood. “Size Analysis with the Coulter Counter, Comparison with Sedimentation and Surface Area Measurements,” by R. Lines. Linnean Society, Burlington House, Piccadilly, London W. 1 (preceded at 5.30 p.m. by a buffet meal in the rooms of the Royal Society of Chemistry). N. Stanley-Wood. Registration is necessary.Contact: Dr. N. Stanley-Wood, Postgraduate School of Powder Technology, Department of Chemical Engineer- ing, The University, Bradford BD7 1PX. (Tel. 0474- 351122). Tuesday, 17th, 4.15 p.m.: Loughborough Midlands Region. Liquid and Enzyme Membrane Electrodes. Speaker: J . D. R. Thomas. Lecture Theatre 5002, Edward Herbert Building, University of Technology, Loughborough. There are no registration formalities. Contact: Mr. H. E. Brookes, 35 Dunster Road, West Bridgford, Nottingham NG2 6JE. (Tel. 0602-231769). Wednesday, 18th, 6.30 p.m.: London Microchemical Methods Group and South East Region. Optical Microscopy. Discussion to be introduced by E. B. Reynolds. Savoy Tavern, Savoy Street, London W.C.2 (subject to There are no registration formalities, but please check venue Contact: Mr.P. R. W. Baker, 55 Braemar Gardens, West confirmation). with Mr. Baker, address below. Wickham, Kent BR4 OJN. (Tel. 01-777-1225). Wednesday, 18th, 6.30 p.m.: Moreton North West Region. Automation in a Pharmaceutical Analysis Laboratory. “Robotics-A Sub-set of Automation?” by K. Leiper. “Extraction of Trace Constituents from Biological Samples with the “Experiences with a Robot in Pharmaceutical Analysis,” by A. N. Aid of Robotics,” by L. Gifford. Hale. “Automated Testing of the Dissolution of Solid Pharmaceutical E. R. Squibb & Sons Ltd., Reeds Lane, Moreton, Wirral. Registration is essential, but there is no charge for the Contact: Mr. T. E. Hanley, 5 Old Hall Court, Ashton, Dosage Forms,” by P. Timmins. meeting. Chester, Cheshire.(Tel. 0829-51609). Wednesday, 25th, 1.30 p.m.: London Special Techniques Group, jointly with UK LIMA UG. Laser Induced Mass Analysis. “The Development of LIMA Techniques,” by Dr. Ruckman. “Instrumental Needs and Design,” by Dr. Griffiths. “New Trends in Instrumentation-The Tunable Laser,” by Dr. “Organic Applications of LIMA,” by Dr. Myatt. “Inorganic Analysis and Quantification by LIMA,” by Dr. Kohler. Lecture Room 1B23, King’s College, The Strand, London, w.c.2. Registration is necessary. Cost f5 to RSC and UK LIMA UG members, f10 to non-members, and no charge to Clarke. student and retired members. Contact: Mr. A. G. Ferrige, Wellcome Research Labora- tories, Langley Court, Beckenham, Kent BR3 3BS. (Tel. 01-658-2211, EX. 5357). Wednesday, 25th, 1.30 p.m.: Hull North East Region. Robotics in Analytical Chemistry. “Sensor-guided Robotics in Manufacturing Industry,” by Professor “Robotics in the Analytical Laboratory,” by T. B. Pierce. “Robotics, People and Systems,” by R. L. Tranter. “Linear Transform Tracks in Laboratory Robotics,” by G. Wilson. Lecture Theatre A, Chemistry Department, The University, Hull. Registration is necessary. Cost f10 to RSC members, f20 to non-members and $2 to student and retired members. Contact: Dr. P. J. Worsfold, Chemistry Department, The University, Cottingham, Hull HU6 7RX. (Tel. 0482- 465469). A. Pugh. Thursday, 26th, 4.15 p.m.: Aberdeen Scottish Region, jointly with the Aberdeen and North of Scotland Section of the RSC and the Aberdeen Students Chemical Society. Electroanalytical Chemistry-Something Old and Something New. Speaker: Professor M. L. Hitchman. Department of Chemistry, The University, Meston Walk, There are no registration formalities. Contact: Dr. J. M. Warren, Department of Biochemistry, Royal Infirmary, Glasgow G4 OSF. (Tel. 041-552-3535, Ex. 5108). Aberdeen.

ISSN:0144-557X    

DOI:10.1039/AP9872400036

出版商:RSC    

年代:1987

数据来源: RSC