JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY AUGUST 1992 VOL. 7 41 N Conference Reports ~ ~ First European Workshop on Surface Analysis by Means of Glow Discharge Optical Spectrometry March 4-6 1992 Paris France On the initiative of the working group ‘Surface Analysis in Giow Discharge Optical Spectrometry’ part of the ‘Groupe Pour L‘Avancement des Sci- ences AnaEytiques’ (GAMS Paris) the first European Workshop on Surface Analysis by Means of Glow Discharge Optical Spectrometry took place in Paris from March 4 to 6 1992. This event sponsored by the LECO Com- pany brought approximately 80 users of glow discharge optical spectrometry from nine European countries together to discuss the stage of development and use of this method for the charac- terization of material surfaces in the participants’ countries show new de- velopment trends expand and co- ordinate the working groups in ques- tion and encourage the propagation of the method in accordance with its productivity.Nineteen lectures were given during five plenary meetings covering the following crucial areas the use of the method in research/development and production; instruments and software; quantification of layer analysis in d.c. discharges; high-frequency (h.f.) glow discharge for non-conductive layers and layer systems; and alternative sur- face analysis methods with ions and electrons. The development of a method for the quantification of GD-OES layer profiies by Bengtson (Sweden) and the implementation of this method in the evaluation-software of commercial glow discharge spectrometers (LECO Instrumente GmbH Munich Ger- many and Jobin Yvon Longjumeau France) represents decisive progress for the method and its use.By Jobin Yvon’s adaptation of the h.f. discharge to the glow discharge as suggested by Grimm for the qualitative depth pro- file analysis of non-conductive layers (ceramics organic layers) the disad- vantage of the limitation of direct current discharge to electrical conduct- ing materials was overcome. Initial method tests (Hunault France) and use of corrosion-protec- tive layers in the car industry (Bau- doin France) show that the referenc- ing and depth resolution of the h.f.- layer analysis are not inferior to those of the direct current dischar‘ge. The workshop made it clear that the exchange of information between European teams working on GD-OES layer analysis has to be intensified in order to elimivate parallel efforts and to ensure the similarity of the results.A connection has to be made between GD-OES and the established surface analysis methods with ions and elec- trons such as SIMS SNMS and AES. By realizing its specific producti- vity/efficiency the GD-OES layer ana- lysis method can be included in the wider field of solid-state physical char- acterizing methods for surface and surface-type materials. In order to promote this and other method-specific concerns a European working team was formed consisting of one represen- tative from each of the participating countries of this first workshop. The European Working Team will gladly welcome further participating coun- tries.Dr. Arne Bengtson of the Swedish Institute for Material Research (S- 1 14 28 Stockholm Sweden) was elected as President. Information about the activ- ities of the working group and the possibilities of active cooperation can be obtained by applying to Dr. Bengtson. A second European Workshop for GD-OES Layer Analysis is planned at the end of 1993/beginning of 1994 in Dusseldorf W. Fischer Institut f i r Reaktorwerkstoge Forschungszen trum Jiilich Gm bH W-5 I70 Jiilich Germany New Approaches to Sample Preparation and Introduction March 25-26 1992 University of Newcastle Newcastle-upon-Tyne UK This year’s joint Atomic Spectrometry Updates (ASU) and Atomic Spectros- copy Group (ASG) meeting took place in the splendid setting of Henderson Hall at the University of Newcastle.On the first day an Executive Com- mittee Meeting followed by an Edi- torial Board Meeting of ASU was held. In the evening a Sherry Reception and Board Dinner took place in the histori- cal surroundings of Langley Castle. After an excellent meal presentations were made by Doug Miles the Chair- man of the ASU Board to the two invited overseas speakers,.. Bernhard Welz from Perkin-Elmer Uberlingen and Ken Jackson from the State University of New York. The scientific meeting on the second day was entitled ‘New Approaches to Sample Preparation and Introduc- tion.’ A diverse range of topics was discussed in the course of the day. Bernhard Welz should have been the first speaker but gremlins in the slide projector delayed the start of his pre- sentation.Instead the first presenta- tion was given by Mike Ramsey (Im- perial College London) who trusted in overhead-projection technology. Mike presented a very challenging lecture on the estimation of errors and in parti- cular errors arising from sampling and sample preparation procedures. He also reminded us of the futility of seeking to improve analytical variance without also assessing these errors which can contribute significantly to the total error. The gremlins having been van- quished Bernhard Welz who was the first of two overseas ASU board mem- bers to present a paper proceeded to discuss his work on on-line pre- concentration using microcolumns prior to determination by electro- thermal atomic absorption spectro- metry (ETAAS). By using CI8 sorbent with sodium diethyldithiocarbamate as complexing agent and ethanol as eluent he had achieved a 20-fold enrichment after a sampling time of only 1 min.This method was able to preconcentrate transition metals from42N Doug Miles (R) presenting a book to Bern- hard Welz sea-water thus offering a clean-up procedure and preconcentration prior to determination by ETAAS. By vary- ing the conditions speciation of Astrt and AsV and of Crttt and CrV1 was also possible. Later in the day Ken Jackson the second overseas board member also discussed preconcentration of transi- tion metals from sea-water prior to determination by ETAAS. Ken how- ever used activated carbon to precon- centrate the analytes after they had been complexed with ammonium pyr- rolidine dithiocarbamate (ammonium pyrolidin- 1 -yldithioformate). A slurry of the carbon was then prepared and injected directly into the furnace. This system offered a 400-fold preconcen- tration of the transition metals. Ken also discussed the use and possible mechanisms of Pd as a modifier when performing slurry ETAAS.He sug- gested that during the determination of Pb crystals of Pd3Pb2/Pd3Pb might be formed which inhibit the vaporiza- tion of Pb thus allowing all the Pb from the slurry to be vaporized at once. This overcame the problem of double peaks that had been experi- enced previously. JOURNAL OF ANALYTICAL ATOMIC Two different aspects of flow injec- tion (FI) were considered by Helen Crews (MAAF Norwich) and Julian Tyson (University of Massachusetts). Helen presented some initial findings for an on-line FI system for microwave digestion of slurried samples prior to analysis by ICP-MS.She used bio- logical reference materials which were prepared to give a 0.02% slurry in 5% HN03. The slurries were passed through a 20 m loop' inside a micro- wave oven and into the ICP spectro- meter. She found that the 0.02% slurry was too dilute for determining most analytes. However where the analyte was present in sufficient amount the results were good. Helen mentioned the need to compromise the optimum flow rate through the microwave oven to allow the optimum flow rate in the ICP spectrometer to be maintained. It was this aspect of the kinetics of FI that Julian Tyson discussed. He suggested putting a sample introduction valve after the FI manifold so that the optimum flow rates for the sample Doug Miles (L) thanking Ken Jackson with a presentation SPECTROMETRY AUGUST 1992 VOL. 7 reaction and flame systqm could be maintained.The valve would then allow the introduction of the reacted sample into the carrier gas flow at the right speed for the flame. The use of a recirculating loop was also proposed. This would allow discrete and repeated analyses of the reacted sample. The winner of the 1991 Hilger Spec- troscopy prize Simon Chenery (Brit- ish Geological Survey) presented a talk on solid sample introduction us- ing laser ablation for plasma spectro- metry. Simon discussed the absolute detection limits of ICP-OES and ICP- MS which then limit the size of sample that can be ablated. Examples of problems requiring small discrete samples were given such as the chal- lenge of determining whether a Rem- brandt is really a Rembrandt.Laser ablation of a flake of paint is an acceptable means of analysis under these circumstances. The final speaker of the day was John Williams (Royal Holloway and Bedford New College Surrey). He highlighted some of the advantages of using electrothermal vaporization as a means of sample introduction in in- ductively coupled plasma mass spec- trometry (ICP-MS). The example of a clinical trial on the uptake of iron by pregnant women was used. It was shown that only small amounts of sample were required sample pre- treatment could be performed in the furnace any water that interfered with the determination of Fe by ICP-MS was driven off and solid or liquid samples could be introduced. Iron enriched with natural isotopes was used in the trial and the isotope ratios were determined by ICP-MS. A wide range of subjects was cov- ered throughout the day and it proved to be a very interesting and stimulating meeting. Janet A. Armstrong Durnfries UK Board members relaxing after an excellent meal are clockwise Julian Obviously enjoying themselves are some members of the ASU Board Tyson Andrew Taylor David Halls Colin Woodward (Editor of clmkwise Bernhard Welz Barry Sharp Doug Miles Ken Jackson ARAAS 1973) John Price John Dawson and Helen Crews Jenny Cook Mike Ramsey Dave Hickman and Judith Egan