JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL. 7 349R ATOMIC SPECTROMETRY UPDATE-INDUSTRIAL ANALYSIS METALS CHEMICALS AND ADVANCED MATERIALS John Marshall* and John Carroll ICI plc Wilton Research Centre P.O. Box 90 Middlesbrough Cleveland UK TS6 8JE James S. Crighton BP Research Centre Chertsey Road Sunbury on Thames Middlesex UK TW16 7LN Charles L. R. Barnard Department of Physical Sciences Glasgow Polytechnic Cowcaddens Road Glasgow UK G4 OBA Summary of Contents Metals 1 .l. Ferrous Metals and Alloys 1.2. Non-ferrous Metals and Alloys Table 1. Summary of Analyses of Metals Chemicals 2.1. Petroleum and Petroleum Products 2.1.1. Crude oil and fractions 2.1.2. Lubricating oils 2.2. Organic Chemicals and Solvents 2.2.1. Chemicals 2.2.2. Solvents 2.3. Inorganic Chemicals and Acids 2.3.1.Chemicals 2.3.2. Acids 2.4. Nuclear Materials 2.5. Process Analysis and Automation Table 2. Summary of Analyses of Chemicals Advanced Materials 3.1. Polymers and Composites 3.2. Semiconductor Materials 3.3. Glasses Ceramics and Refractories 3.3.1. Glasses 3.3.2. Ceramics refractories and catalysts Table 3. Summary of Analyses of Advanced Materials This Atomic Spectrometry Update is the latest in an annual series appearing under the title of ‘Industrial Analysis’. The structure of the review is the same as that used in previous years. Significant advances have been made during the year under review in the design of GD cells for the analysis of conducting and non-conducting materials. It is evident that the development of r.f. boosted discharges and more practical cell geometries has extended the range of the technique. Applications continue to increase in the multi-layer metals field and there are signs that the semiconductor and materials fields are seeing some of the benefits of this technology such as depth profiling.Techniques involving laser ablation (LA) sampling are also increasing in popularity for the characterization of solids reflecting the requirement for the differentiation of material functionality in situ. Sensitivity is still an issue in many fields as demand for increasingly high purity chemicals and materials grows. Thus preconcentration procedures continue to be reported. The opportunity such methods provide for chemical speciation is evident and chromatography is becoming an essential preparatory tool in the armoury of laboratories involved in inorganic analysis. 1.METALS This section of the review covers the analysis offerrous and undoubtedly the largest number of abstracts refer to nonferrous metals and alloys by analytical atomic spectro- methods based on ICP-AES. Sample treatment method- metry. A summary of the analytical methods reported for ologies such as matrix separation dissolution and direct the analysis of metals in the year under review is given in introduction tended to predominate in the literature. Table 1. Details of these procedures can be found in Table 1. The development of procedures for on-line analysis of molten iron (9211924) and steel (921C3496) has been 1.1. Ferrous Metals and Alloys reported. This was achieved by continuous monitoring of A wide range of analytical techniques have been applied the spectrum from a hot-spot generated by the application to the analysis of ferrous metals in the Past Year but of a stream of oxygen impinging on the surface of the molten metal.This relatively rapid technique (typical *Review Co-ordinator to whom correspondence should be ~ ~ a s u r e m e n t Period 15 S> could be applied to those elements that had a vapour pressure significantly higher addressed.3 50R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL. 7 Table 1 Element Ag Ag Ag Al A1 Al Al Al A1 Al A1 As As As SUMMARY OF THE ANALYSES OF METALS Technique; atomization; analyte form* M S; ICP; L Matrix High-purity copper Sample treatmentkomments Sample digested in 50% HNO and mixed with 50 mg of tellurium extracted with HCI reduced and redissolved in HNO,; an LOD of 0.1 1 ppb Ag and precision of 3.8% were reported using isotope dilution Experimental parameters optimized to give sputtering rates of 0.24 mg s-I cm-2 (at 40 mA and 0.15 mbar); LODs of 0.010% and RSDs of 3% were reported Sample mixed with Florisil-CaO heated to 1200 "C when the volatile Ag was transferred into the flame in a stream of purified air An arc-shaped platform was treated with molybdate to reduce matrix effects; RSDs of 1.22-3.38% were reported Acid soluble fraction Magnesium sulfate chemical modifier and pyrolytic graphite tubes were used to avoid interference from iron filtered (0.45 pm); acid soluble Al obtained by alkaline fusion in a 1 + 1 H,BO,-K2C0 mixture ashed at 1000 "C Extraction with C,7-C20 carboxylic acids gave 99% extraction of Al at 60-80 "C Glow discharge cleaning removed surface contamination by C Na F and CI by reaction with H atoms MS and GD-MS Sample is dissolved in HCl-HN0,-H,O (3 + 1 + 2) Computerized interference table described for ICP- Direct sputtering and depth profiling On-line continuous FI manifold for matrix isolation and HG from NIST and BAM reference materials; RSD 1.59/0 ( I0 ppb n = 12) reported Samples dissolved in HNO and HCl and As determined at 193.7 nm.An RSD of 2.8% was reported for 199 ppm of As in pig iron Sample dissolved in HN03 (1 + 1) and As was co-precipitated with MnO and re-dissolved in HN0,-H202. Matrix interferences were removed by addition of 100 ppm of Ba Ca or Ma Samples dissolved in HCIO or H,SO BCS CRM alloy digested in 4% HNO,-48% HF in a microwave oven gave AsV.The system gave an LOD of 0.5 ppb and an RSD of 3.5% at 10 ppb As Samples were extracted into xylene-2-ethyl- 1,3- hexanediol; an LOD of 1.6 ppb was reported Diffusion of B in alloy characterized Dissolution by high-pressure microwave digestion. Isotope dilution LODs of 10 fg g-' were reported; precision was found to be less than 3% Dissolution in acid and generation of methyl borate Samples were dispersed in a B,C-Mo medium; alpha- factor correction gave a 'fairly' linear calibration Particulate Be was boiled in a solution containing 2% HNO Sample was dissolved in concentrated HNO and converted into its hydride Samples were dissolved in 0.1 mol dm- HCI and 0.4 mol dm-' HNO and passed down an AGMP-50 macroporous cation-exchange column which separated analyte from matrix tungsten probe coated with trioctylphosphine oxide then immersed in a 20 ppm Ni solution to remove the excess Samples dissolved in HCI were deposited on a Reference 91/3855 92lC664 9213600 92159 9211 9 18 9211919 9212273 9212952 9213098 9213428 92lC37 56 91lC3632 9113859 9 113864 92/3 187 92lC3663 921248 921 1526 92x3345 9 2 x 3 3 8 2 92/2536 9212990 92/20 10 921249 1 High-purity gold AE;GD;S AA;F;G Copper ore AA;ETA;L Steel Steel Steel AE;spark;L AA; ETA;L Non-alloyed steel AA;F;L Copper- nickel- and zinc-based alloys Aluminium alloy X R F -; - SIMS; -; - Standard solid MS;GD or AA;GD;S AA;ETA FI Hy;L 1CP;S or L Coatings of silicon wafers Copper metal AA;ETA;L Iron and steels Iron copper and nickel AA;ETA;L As Manganese steels As Nickel-based alloy AA;Hy;L AA;FI Hy;L B Steel AE;ICP;L B B Amorphous alloy Steel CRMs SIMS; -; - MS;ICP;L B Be Steel Niobium-beryllium alloys AE;ICP;L EPMA AA;F;L Be Standard beryllium Bi High-nickel alloy AA;Hy F;L Tellurium mercury gold or platinum metals Bi Bi ZAA;ETA;L 921268 1 Copper alloyJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL.7 351R Table 1 SUMMARY OF THE ANALYSES OF METALS-continued Technique; atomization; analyte form* AA; F; L SEM;X-ray;S XRF-;S XRFi-iS Element Matrix Ca Iron-nickel alloy Cd Gold-silver alloys Ce Steel c o Iron Sample treatmentlcomments Use of dinitrogen oxide-acetylene flame for improved sensitivity for Ca Detection of Cd in modern solders to distinguish from antique Cd-free solders Measurement of dopant levels e.g.0.001% at the La line Sample was dissolved in acid peroxide mixed with citrate and precipitated from solution at pH 7.0 with 2-nitroso-1 -naphthol. Co was determined at 50 kV 30 mA for a counting time of 40 s ammonium thiocyanate adsorbent supported on naphthalene; Co chelate was stripped from the column with DMF Preconcentration on tetradecyldimethylbenzyl- Dissolved in HCI Reference 9113852 92/27 1 9212937 921294 9213880 92lC3 7 3 5 92150 921C664 92lC72 1 921969 921 1 628 92lC359 1 92lC3670 92K3772 9113773 9113868 921 1 I92 9212937 921 1 397 921 1 848 9212 89 7 92lC3 3 52 921 1809 921 1 924 9212237 c o Aluminium alloys and steel AA;F;L Cr Chrome-phosphate surface c u Aluminium alloys coatings on aluminium AA,AE,XRF;-;- AA;F;L AE;GD;S AA;F;L MS;-;S Electrolytic dissolution into HNO,; repeatability of As for Ag Precipitation of Ag as chloride salt; extraction of Cu Fast atom bombardment and time of flight MS used 4-5% reported from the precipitate to monitor scatter of neutral species.Characterization of the Cu surface Excitation mechanisms and plasma composition investigated and resonance charge transfer between Cu atoms and plasma gas species reported to be main feature Direct analysis of solid samples in a graphite cup introduced into the ICP and time-dependent emission profiles used to separate analyte from matrix cavity described for which 26% of Cu was ablated and transported to the detector system Direct solid analysis by volatilization of sample using a high-voltage spark Metallic Fe is sputtered from the cathode surface and excited with a Nd:YAG pumped tunable UV laser; sub-ppm detection reported Samples were dissolved in 5 mol dm- HNO spiked with a mixture of "Ga and 69Ga (in 1 mol dm-' HNO,).The solution was evaporated to dryness and dissolved in 7 mol dm- HCI then extracted into isopropyl ether and evaporated to dryness and dissolved in 1 .O rnol dm - HNO Redox reactions were used to bind analyte to Cu substrate. Optimization of experimental parameters gave detection at sub-pg levels As for Ce Effect of Li compounds on corrosion of steel LA chamber was characterized and a cylindrical demonstrated that Li ions penetrate the grain boundaries Dissolution in HNO Bulk spectra of the alloy exhibited martensitic transformations that were not observed for Li evaporated on cooled substrates Optimization of sample ablation factors gave usable precision of 1-2% Samples were decomposed in HCI-HNO in a PTFE chamber; Mn was separated from the matrix on a cation-exchange microcolumn with 95% recoveries On-line monitoring of hot-spot generated when oxygen impinges on the Fe offered good correlation between emission intensity and Mn concentration from 0.26 to 1.09% Depth profile analysis revealed that the surface layer was enriched with Mn c u High-purity gold cu Silver nitrate cu Copper cu Copper metal AE;GD;S cu Lead and zinc AE;ICP;S cu Copper metal MS;ICP;S cu Copper alloys Fe Iron MS;ICP;S AF;GD;S Ga Aluminium MS;ICP;L Ir Copper AE;GD;S La Li Steel Steel Li Li Lead-lithium Lithium-magnesium A€; 1CP;L Soft X-ray emission Mg Mn Aluminium metal Nickel and tantalum AE;laser plasma;S AA;ETA;L Mn Molten iron AE;-;L Mn Steel AA;F;L352R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL.7 Table 1 SUMMARY OF THE ANALYSES OF METALS-continued Technique; atomization; analyte form* AA;ETA;S Element Matrix Mn Molten steel Sample treatmentlcomments Metal vapour above the molten steel condensed to fine particles and introduced into an electrically heated absorption cell in an argon carrier gas Characterization of diffusion and etching profiles for a GD cell Sample dissolved in acid and extracted as its 5,S-methylene disalicylo hydroxamic acid complex into IBMK; Mo determined as its thiocyanate complex with an LOD of 0.03 ppm determination of N at 149.2 nm giving an LOD of Use of specially coated optics permitted 10 PPm Cathode sputtering atomizer with potential for depth profiling was characterized.An LOD of 24 ppm was reported for a 1 nm thick layer of Mo Most (97.5Oh) Ni was precipitated from solution as its dimethylglyoxime complex and Ni in the filtrate determined with a precision of 0.039% Propane-butane-air flame used with addition of triethanolamine and Sr eliminated depression of Ni signal; an LOD of 0.001% was reported Samples fused in an induction furnace for 2 min then compressed at 200 MPa for 10 s. Analysis time was 15-20 min Low ppm detection of 0 required careful reduction of background Sample solutions with 2-5-fold excess of ammonium molybdate mixed with diantipyrylmethane; indirect method based on Mo detection complex into IBMK has a sensitivity of 0.02 ppm; no interferences were found subjected to an r.f.spark discharge which created a colloidal dispersion which was directly nebulized Sample was dissolved in 7 mol dm-3 HNO,; adjusted to pH >2.0 and mixed with manganese nitrate and permanganate to co-precipitate matrix with MnO,. The filtered precipitate was re-dissolved in 2 mol dm-3 HNO and H,O for detection of Pb Pulsed mode and continuous wave sample sputtering in a hollow cathode atomizer were capable of LODs in the region of 40 ng g-l Discharge conditions were optimized for quantitative analysis so that emission yield was independent of sputter rate calibration was linear to 50 ppm with RSDs in the range 1.19-2.35% Solvent extraction of a phosphantimonyl molybdate Samples were immersed in high-purity water and Samples were determined in HCI-HBF and As for Ir Sample solutions were treated with sodium sulfite to convert any SbV into Sb"' and the stibine swept into a STAT system heated by an air-acetylene flame determination; an LOD of 0.056 ng and RSDs of less than 5% were reported Samples were decomposed in HNO prior to As for As Samples were extracted with dibutyl sulfide in toluene and determined in a double tube furnace arrangement. The LOD was 5 x RSD less than 7% Solvent extraction with potassium xanthates was most efficient at pH < I .5.The method gave a reported RSD of 1.3-1.7% for samples in the range 10-50 pm of Sn g with an Reference 9213867 9211 629 9212487 92lC603 9213606 9 114039 9211927 9212958 92123 14 9212267 921243 1 92lC33 70 9213406 9213607 92x3727 921 164 9211 192 92/3770 9113853 9 llC3632 921 149 Mo Molybdenum metal Mo Steel MS;GD;S AA;F;L N Steel AE;spark;S AF;GD;L Na Molybdenum Ni Ferro-nickel AA;F;L Ni Alloys of aluminium copper and zinc AA;F;L Ni Copper XRF-;S 0 P Alloys Ferro-alloy MS;GD;G AA;F;L P Copper alloys AA;F;L P Copper alloys AE; 1CP;L Pb Zinc AE;ICP;L Pb Copper A€-;S Pb Steel AE; GD;S Titanium alloys AA;F;L Pd Pt Sb Copper base Copper based alloys AE;GD;S AA;F;L Sb Iron and steel AA;ETA;L Se Sn Copper metal Gold AA;ETA FI Hy;L AA;ETA; L Sn Aluminium alloys AE;ICP;L 921302JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL.7 353R Table 1 SUMMARY OF THE ANALYSES OF METALS-continued Element Matrix Technique; atomization; analyte form* Sample treatmentlcomments Ta Niobium-based alloys AE;ICP;L Analyte separated from matrix by precipitation with tetraphenylarsonium chloride in ammonium hydrogen fluoride and H,SO,; then treated with H,SO,-HNO and dilute H,O Te Copper AA;ETA;L Samples were separated by solvent extraction with IBMK from a 6 mol dm- HCI solution with a linear working range of 0-0.3 ppm extracted into 10% vlv tributyl phosphate in cyclohexane.For 10 g of sample an LOD of 7 pg g-' was reported Th Aluminium MS;ICP;L Samples (dissolved in 10 mol dm- HCI) were As for Th U V Aluminium Ferro-vanadium MS;ICP;L AE;ICP;S V w Steels Nickel-based alloys Various (5) Alloys Various Microalloyed steel Various (7) Alloy Various ( I 5) Zirconium alloys Various (20) Gold Various (10) Ferro-chromium and ferro-manganese Various (1 5) Non-ferrous metals Various Alloys Various (7) Steels Various (8) Iron Various ( 13) Copper Various ( 13) Palladium Various (6) Low-alloy steel AA;ETA;L AA; F; L AE;ICP;L AE;ICP;S AE;ICP;L MS;GD;S AA;F;L Samples were homogenized by melting and diluting with pure Fe in a high-frequency furnace followed by centrifugation.Use of spark ablation for aerosol production gave repeatability of better than 0.4% Complex dissolution-oxidation-extraction procedure using HNO and HC1 K2S208 and KMn04 and IBMK then tributyl phosphate and H,O respectively; the LOD was 0.3 ppm with an RSD for NIST SRM 361 of 3.79/0 (n= 17) 0.5 g of a finely milled sample was dissolved in 1 +4 HF followed by a 3+ 1 mixture of HCI and HNO while heating.The cooled solution was mixed with H,PO and acetone then diluted On-line electro-dissolution in a flow-through cell with FI Comparison of conventional nebulization with spark pre-atomization Rapid two-step microwave decomposition using a mixture of HCl and HNO,; precision of 0.4% was obtained by use of internal standards source gave a reported precision of less than 4% for ten elements and LODs of less than 0.5 ppm for 13 elements permitted determination of elements with LODs in the range 0.002-0.4 ppm with RSDs from 3 to 8% Samples were dissolved in a mixture of phosphoric and sulfuric acids in a PTFE vessel; reported LODs ranged from 12 to 120 ppb Samples were digested with a ternary reaction mixture (HCl H,O MnO,) in a closed thermostated reactor.The method was applicable to determinations in the range 0.0O2-9O0h mlm reported detection range of 10 ppb-I0 ppm with total analytical precision between 1 and 6% relative YAG LA produced fine particles giving detection in the range 0.01-5.6 ppm for 0.18 s integration time Matrix was removed by solvent extraction into IBMK; analysis was carried out by TXRF. Reported LODs were of the order of 100 ng g-I Multi-element preconcentration is achieved by reductive matrix precipitation and LODs of between 0.1 and 5 ppm are achieved for FAAS and 0.01-0.1 ppm for ETAAS; typical RSDs were 3% (n= 12) were in the range 0.6-9.4% Nd:YAG laser and swept into the ICP; analysis of NIST 1767 SRM was reported and RSDs in the range 3-9% were obtained Direct analysis with a gas-jet enhanced sputtering Micro-batch anion-exchange matrix removal FI with on-line electrolytic dissolution gave a AE;ICP;L MS;ICP;S Sample was dissolved in 10% HCI and the RSDs Samples were vaporized with a 500 mJ pulse from a AE;ICP;L AE;ICP;L AE;ICP;L MS;ICP;S XRF-;L AA;F;L Reference 9213504 9212226 92J3596 9213596 921C593 921 1706 921295 1 92157 921249 92lC594 9211 2 12 921201 8 9212405 9212444 9212762 92lC3 568 9213792 9 113882 9213975 9214029 * Hy indicates hydride generation and S L G and SI signify solid liquid gaseous or slurry sample introduction respectively.Other abbreviations are listed elsewhere.354R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL. 7 than that of the matrix.In these studies Cr Cu Mn Ni and Pb were detected with an optical fibre connected to a high- resolution monochromator. The use of electrical sparks for pre-atomization of samples continues to find application in metallurgical analysis (9213200). A direct comparison of spark ablation and conventional nebulization ICP-AES indicated that both techniques possessed similar detection and precision characteristics (921249). Thus spark ablation into an ICP has been found to be a reproducible method for the determination of V in steels (92/C593). The determination of low levels of N in steel by spark emission spectrometry has always been difficult owing to sensitivity limitations (= 100 ppm) in the UV region of the spectrum. However the use of magnesium fluoride coated optics coupled with a lithium fluoride entrance lens and a far-UV sensitive phototube has been found to improve the response for N at 174.2 nm (921C3737). It was reported that an improvement in detection limit of two orders of magnitude could be achieved by means of these instrument modifications.A spark source MS technique was described for the determination of H in stainless steels using a pointed metal probe (92/ 1293). The H background level was reduced for the sample in the ion source by vacuum-backing at 323-343 K. The levels of H reported in austenitic steel were in the range 2-4 ppm with an RSD of 20%. Spatial selectivity is not readily available by spark ablation and where this criterion is important the use of laser ablation (LA) is found to be most appropriate (92/ 1252) irrespective of the detector to be selected.The use of ICP-MS continues to gain ground but to a lesser extent than for non-ferrous materials. A report describing the determination of a range of elements in iron materials indicated no significant bias in ICP-MS (92113 16). A typical precision of about 10% relative was achieved for As Co Cr Cu Ga Mo Ni Pb Sb Sn and V. However it was also noted that the determination of Al B Ca C1 F K Na N 0 P S and Si had to be carried out by other means. Spectral interferences arising from the analyte interactions with sample and digestion matrix elements and from plasma gas species have also been the subject of investigation (921C349 1 ). The suppression of ICP-MS analyte ion signals in a steel matrix has also been reported (9212087).A direct sampling approach such as LA can be used to avoid solvent-related interferences in ICP-MS. Thus a Q- switched Nd:YAG laser operated at 15 Hz repetition rate was used to vaporize nanogram amounts of Low-alloy Steel (NIST SRM 1767) prior to the determination of Ag Pb Rb Sr,Th and U by ICP-MS utilizing silicon as an internal standard element (9214029). The reported method gave results in good agreement with certified values with RSDs in the range 3-9%. Studies have also been made using a CW Q-switched Nd:YAG laser focused onto the sample surface (921C3568). It was reported that fine particles of the order of 0.02 pm were generated with a relatively high ablation rate of 22 pg s-I. The accuracy obtained was reported as being ‘acceptable’ with precisions in the range 5-10%.Detection limits were in the range from 0.01 ppm for Nd to 5.6 ppm for Ni using an integration time of 0.18 s. The design and development of GD sources has received attention during the period under review. Glow discharge AES has been applied to the determination of V in steels (921229). A dual cathode lamp was described in which background radiation from the filler gas was eliminated. Using this cell the interference of the argon 437.97 nm line on V at 437.92 nm was avoided. The method was reported to be suitable for the determination of V in steel in the range 0.1-2.5% m1m. A GD source was reported which was a modification of the Grimm design incorporating a floating restrictor (92/ 1 193). The cell was devised in such a way that it could be used directly in place of an ICP source in a conventional ICP-MS instrument. The operation of the GD required that the anode was given a slight positive bias with respect to the earthed skimmerhterface plate of the MS.Secondary ion MS and sputtered neutral MS have both found application in the quantitative analysis of steels (92~572). Two techniques were described for depth profil- ing and surface analysis of zinc-coated steel samples. An apparent bias in the XRF determination of Ti in steels has been reported (9113878). The problem was observed during the analysis of NIST SRMs 1165 and 1264 Low- alloy Steels. It was considered that differences in metallurgical uniformity were the major cause of the bias as discrepancies were not found using other techniques.Electron probe data revealed the existence of Ti inclusions containing varying amounts of Nb Ta and Zr which supported the inhomogeneity hypothesis. 1.2. Non-ferrous Metals and Alloys More than two thirds of the 330 abstracts received concerning metals referred to the analysis of non-ferrous metals and alloys. Most of these papers described the characterization of aluminium- copper- or nickel-based alloys and details are provided for convenience in Table 1. The majority of applications described improvements in the area of sample preparation or presentation. The determination of Cu in aluminium alloys using FI- FAAS has been described (92150). The solid metal samples were dissolved in 0.2-1.0 mol dm-3 HN03 on- line using an electrolytic approach.The effect of electro- lyte composition and electrolysis parameters on the disso- lution of samples was investigated. The repeatability attained for the measurement of Cu in aluminium alloys in the concentration range 0.5-10% was of the order of 5% relative. Microscale electrolytic preconcentration pro- cedures were used for the determination of Cd and Pb in silver (9212769). Anodic dissolution was used to dissolve microgram amounts of the sample and the analytes were simultaneously separated from the silver matrix by elec- trolysis. The determination of Cd and Pb in the electro- lyte was carried out by FAAS. Other reports also describ- ing the use of electrolytic sample dissolution prior to analysis might be of interest (9212762 921C3370 92/C3588).A microbatch anion-exchange method was used for matrix separation in the determination of trace elements in gold (92/2018). This rapid method was developed for the separation of strongly bound metals (e.g. gold palladium bismuth) prior to FAAS detection of 20 trace elements. Detection limits in the range 0.002-0.4 ppm were reported with RSDs in the range 3-8% depending on the analyte of interest. A similar procedure based on microscale ion- exchange separation was described for the measurement of trace amounts of Mn in niobium wire and tantalum powder by ETAAS (9211809). The calibration graph was linear over the range 0.003-0.2 mg of Mn. The recovery obtained for Mn after preconcentration was 95%. The problem of competition between matrix ions and the reducing agent in the HG process may be overcome using FI-AAS in conjunction with on-line matrix isolation (911C3632).The procedure was applied to the determina- tion of Se in Bundesanstalt fur Materialforschung und - priifung (BAM) 36 and NIST SRM 454. These were found to contain 30 and 479 mg kg-l of SeiV respectively. A characteristic concentration of 1 ppb was reported for the method with an RSD of I .5% (1 0 ppb of Se n = 12).JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY. DECEMBER 1992 VOL. 7 355R It has been reported that the use of the graphite cup sample insertion technique can be employed to reduce significantly matrix interferences in the determination of Cu and Fe in lead and zinc metals (92/C359 1). Thus when 20 mg of the metal sample were introduced in a cup into the ICP the matrix was preferentially evaporated on a tempo- ral basis since the analyte elements exhibited higher boiling-points.Time resolved emission profiles allowed the measurement of Cu and Fe with detection limits of 5 and 20 ppb respectively. Spark elutriation can also be used in the reduction of matrix interference effects (92/C337 1). A spark ablation unit was constructed from PTFE with ceramic mounting for the tungsten electrode on one side and the sample on the other side. The sample was subjected to a spark of up to 800 V with frequencies in the range 50-400 Hz in an argon atmosphere. A peristaltic pump was used to remove liquid from the sample surface thence to the ICP. The results indicated that good agreement with the ex- pected results was obtained.Spark ablation sampling for FAAS was used to determine a range of elements in metal alloys (92K775). A spark was applied to the sample under the surface of a solid which resulted in the generation of a lisol-like suspension (i.e. particle size > 1 pm). Matrix effects were found to be minimal when employing this approach and this allowed calibration of response using aqueous standard solutions. One of the perceived limitations of the use of LA for direct sampling of metals by ICP-AES is that of relatively poor repeatability and it has been claimed in a recent report that this has prevented the technique gaining more widespread acceptance (92K3352). Thus a 400 mJ xenon chloride laser with a time gated multi-channel spectrometer was used for the determination of Mg in aluminium.It was demonstrated that the repeatability of the method was 1.3% relative for Mg at the 1% concentration level. A theoretical model has been developed to describe the processes which affect the shape of the transient signal associated with single-shot LA (92IC3353). It was found that a bead packed tube and simulated dispersion produced a response curve which closely matched the spikey profile of the LA-ICP transient signal. Sample entrainment and transport in the ablation of Cu prior to determination by ICP-MS has been the subject of a recent study (92/C3670). It was reported that for a cylindrical chamber 120 mm high and 25 mm in diameter approximately 26% of the ablated Cu would be transported to the detector. However only 44% of the total Cu was accounted for.A hypothesis was put forward suggesting that the remainder could be in the form of small Cu clusters. Ultra-high purity aluminium is used in applications associ- ated with integrated circuit components. There is a require- ment for methods for the determination of Th and U at levels close to 1 ppb (92126 13). Laser ablation ICP-MS has been applied to this problem and detection limits of the order of 0.2 ppb have been achieved. Inductively coupled plasma MS has also been applied to the determination of B at ppm levels in a titanium matrix. Beryllium was used as an internal standard for the determination of B in Commu- nity Bureau of Reference (BCR) 090 SRM and the results obtained agreed with the certificate values. Isotope dilution can be used to achieve good precision in ICP-MS.This feature was used in the determination of Ag in high-purity copper (91/3855) by ICP-MS. The sample was digested in 50% v/v aqueous HN03. Approximately 50 mg of tellurium were added to the solution which was then evaporated to dryness redissolved in HC1 reduced and filtered. The precipitate was redissolved in HN03 and Ag determined by ICP-MS. The detection limit was reported to be 0.11 ppm and typical precision was of the order of 3.8%. A magnetron GD plasma has been applied to the analysis of zinc-based NIST SRMs (92/2058). The device was capable of operating over a wide range of pressures [0.0007-2.5 Torr (1 Torr= 133.322 Pa)]. The operating conditions were optimized for each analyte. Detection limits for Mn and Ni were reported to be 0.006 and 0.0005 5'10 respectively.The performance characteristics of a new cathodic-sputtering atomizer for AAS have been described (91/3806). The ability to control the flow and pressure of argon in the atomizer was claimed to result in a 5-fold improvement in sensitivity compared with a com- mercially available atomizer. A system was described in which two pulsed GD sources were housed within one source (92/2659). Two isolated cathodes were placed parallel to each other to allow simultaneous comparison of an analytical sample and a reference standard. The effect of sample positioning was studied by GDMS using a pair of identical SRM 1262 cathodes. It was found that the optimum arrangement resulted in RSDs in the range 2.2-5.2%. When two different cathodes SRMs 1262 and 1263 were used the error was in the range 0.75-9.1% relative.The potential of a cathodic sputtering cell was investigated for use as an atom cell for ultra trace analysis using laser-induced fluorescence (9 1/3773). The cell which had been designed to be used in AAS was applied to the determination of Fe in brass. Sensitivities in the sub-ppm range were reported with accuracy and precision of the order of 15%. Noise studies indicated that the principal limiting noise arose from laser-induced background signals. Glow discharge MS has been applied to an in-depth analysis of the surface layers of nickel-chromium multi- layer systems (92K3462). It was found that in order to achieve acceptable depth projle data it was necessary to ensure that flat crater profiles were produced during sputtering.This was achieved by careful control of the burning voltage. A penetration rate of 100 nm s-' was established and this was sufficient to complete the analysis in a few minutes. A novel type of combined bipole deflector was developed to reduce the disturbances in MS detection resulting from photo-radiation and neutral particles in an r.f. GD source (92/1062). The deflector consisted of half cylindrical electrodes and diaphragms with eccentric aper- tures. A high S/N was claimed for the device. Glow discharges can be used to clean the surface of samples and the efficacy of this process has been studied using SIMS (92/3098). Contaminants on the surface of an A6063 Aluminium Alloy were found to include C C1 F and Na.The concentrations of these contaminants were effectively reduced using the GD cleaning process in a hydrogen atmosphere. Secondary neutral MS has been applied to the characterization of nickel-chromium multi- layer thin Jilms (92/26). It was reported that quantitative sample composition and absolute depth projling could be achieved by using correction for variations in the time dependency of the sputter rate for all elements if the particle density in the sample was known. The determina- tion of trace amounts of 0 in copper has been carried out using SIMS (92/1562). The analyte could be detected in the negative ion mode at m/z 16 or as the copper oxide polyatomic ion at m/z 79 without the interference of residual gas. The ion intensities were normalized to the copper matrix response and it was found that there was a linear relationship with bulk oxygen concentration in the range 0.5-106 ppm.The application of XRF to the characterization of thin jlms has been the subject of a review (9113821). The report indicated that X-ray absorption enhancement was caused by interelement effects in single-layer systems. The accu- racy of analysis was estimated as 1% for composition and 3% for thickness determination.356R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL. 7 2. CHEMICALS 2.1. Petroleum and Petroleum Products Elemental analysis of petroleum related materials has continued to attract significant attention amongst workers in the field of atomic spectrometry reflecting the economic importance of this type of analysis.A summary of papers received during the review period is given in Table 2. In addition a two part review (total 165 references) has been published (92/3070 92/307 1 ) which discussed the occur- rence and significance of trace elements in petroleum and petroleum products and provided a critical comparison of modern instrumental methods of analysis. A more specific review (24 references) covering application of plasma spectrometry in the petroleum industry has also been published (92/3891). 2.1.1. Crude oil and fractions As discussed in last year’s review determination of trace elements in crude oil can provide valuable information that can be used alongside traditional biomarkers such as steranes and triterpanes in assessing the origin and maturity of petroleum for exploration purposes.However perhaps an even more important reason for concern about trace elements in crude oil is that these elements are concentrated in the heavy fractions during distillation and can poison the cracking catalysts used for upgrading. Elements present at relatively high (pg g-l) concentrations (e.g. Fe Ni and V) can be determined using X-ray fluorescence (9213079 92/3 195) but alternative approaches are generally required for lower concentrations. Gonzales and Lynch (92/3073) have discussed direct analysis of crude oils for 18 elements using ICP-AES (kerosene dilution with scandium as inter- nal standard) while Al-Swaidan and Hassan (92/1255) have described a wet ashing procedure for the determination of Al Cd Fe K Li Mn Ni Pt Sn and V using ICP-MS.The latter procedure involved treatment with concentrated H2S04 drying and ashing followed by dissolution in HN03. If only a limited number of elements are to be determined however then this can be accomplished effec- tively using ETAAS with LODs down to sub ng g-’ levels (92/1379 92/ 17 16 92/ 179 1 92/ 1793 92/ 1877). A mi- crowave wet ashing procedure for determination of Cr Cu Fe Ni and V using ETAAS and Na and Zn using FAAS may be of particular interest (92/3 146). Direct analysis of petroleum products using ICP-AES generally requires dilution with an organic solvent. This can cause plasma instability and inferior sensitivity particu- larly if volatile solvents are used. Use of an ultrasonic nebulizer has been reported (92/C33 16 92/C3757) which reduced plasma solvent load and led to markedly improved analytical performance.Organic solvents can cause even more problems with ICP-MS because of blocking of the sampling cone with carbon deposits and carbide molecular ion interferences in the mass spectrum. A novel approach to solving this problem was reported previously at a confer- ence and discussed in last year’s Atomic Spectrometry Update (see J. Anal. At. Spectrom. 1990 5 323R). The method now published (92/ 1242) involves direct nebuliza- tion of the oil sample prepared as a micro-emulsion in water. Accuracy and precision were within 3% but LODs were restricted to 0.1 pg g-*. A similar approach has been reported for AAS analysis of crude oil samples using a mixed solvent system (91/3911). In both cases require- ments for organo-metallic standards were eliminated. Finally a novel approach for elemental analysis of crude oil has been reported that involved decomposition of the sample by flow through oxygen combustion with determi- nation using AAS (921C507).This approach could be particularly useful for the determination of volatile ele- ments which can be subject to selective volatilization problems if sample nebulization is used. It is increasingly being recognized that for many applica- tions it is necessary to know not only the total concentration of elements in a sample but also their chemical form. In last year’s review some preliminary information on chemical speciation of elements in petroleum related material was discussed and it was predicted that many more applications would be reported in future years as suitable instruments became more widely available.This has indeed happened and this year has seen an explosion of papers dealing with chemical speciation mainly utilizing a combination of chroma tograph ic separation techniques with el em en t specific detection using atomic spectrometry. Speciation of metallo- porphyrins can provide valuable information on the origin and maturity of petroleum and shale. Quimby et al. (9 113909) have reported the use of GC-MIP-AES for deter- mination of volatile Ni V and Fe porphyrins. However most porphyrins are not volatile enough for this approach and so the use of reversed-phase HPLC with ICP-MS detection has also been attempted (92/C454 92/C3472 92/C3473).Although relatively successful the method does not have adequate chromatographic resolution to compete with the more conventional approach using normal-phase HPLC (UV detection) after de-metallation of the porphy- rins. A novel approach to characterization of metal species in kerogen and other petrochemical precursors has been re- ported by Uden et al. (92K3469). The method involved pyrolysis GC-MIP-AES with on-line butylation of acidic species using tetrabutylammonium hydroxide added to the pyroprobe. Chemical speciation of elements is even more important in refinery streams and products. This is particularly true for suIfur compounds. As sulfur concentrations in available crude oils rise and environmental legislation limits sulfur concentrations in products (e.g.fuels) the availability and efficient operation of desulfurization processes is becoming ever more critical. A prerequisite for this is knowledge of the chemical forms of sulfur compounds in the extremely complex mixtures that comprise the refinery streams. Quimby et al. (9 1 /C37 19) have described automated software for sulfur specific simulated distillation using GC-MIP-AES while Eckert-Tilotta et al. (921C3723) have reported favourable performance of MIP-AES compared with chemiluminescence for sulfur specific GC detection. Heavier petroleum fractions are not amenable to GC analysis but characterization of sulfur species has been accomplished using X-ray absorption spectroscopy (9 1/3986 92/3856). Speciation of alkyilead compounds continues to attract significant attention in view of the impact of these compounds on the environment.Caruso et al. (9 1 /3907) have applied reversed-phase HPLC-ICP-AES and HPLC-ICP-MS for speciation of inorganic and several trialkyllead compounds. Limits of detection were three orders of magnitude better using ICP-MS detection but gradient elution could not be used owing to plasma instability. For non-ionic alkyllead compounds better chromatographic separation can be achieved using GC. Speciation of organolead compounds using GC-AAS has been reviewed (92/3115) while Caruso et al. have also reported use of GC-ICP-AES (9 1 /C3708). However LODs better by several orders of magnitude can be achieved using capillary GC-ICP-MS (92iC455). Limits of detection using the latter approach were better than 1 ng g-’ for a 1 p1 split injection.The determination of oxygenated compounds in gasoline is of great topical interest. These compounds are added to reformulated gasoline to reduce carbon monoxide emissions and will be mandatory under US legislation by 1995. Goode and Thomas (921C3434 92/C38 13) have shown that GC-MIP-AES is an ideal technique for thisJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL. 7 357R Table 2 SUMMARY OF ANALYSES OF CHEMICALS Technique; atomization; Element Matrix analyte form* PETROLEUM AND PETROLEUM PRODUCTS- Sample treatmentlcomments Reference As Feedstocks Ba Lubricating oil AA;ETA; L AA;FL Direct analysis using Zeeman AAS FAAS method using air-C,H flame with sodium dodecyl sulfonate and benzyl trimethyl ammonium chloride mixture as enhancing agent.Results compared well with DIN and IP methods using N,O-air flame 13C:1zC ratios determined for any component of crude oil natural gas or source rock extract using GC interfaced to isotope ratio MS via a combustion unit Speciation of volatile Fe porphyrins using GC-AES (302.1 nm). Detection limits for Fe Ni and V porphyrins were 0.05-5 pg s-I Direct determination of Fe Ni and V in fluidized cracking catalyst (FCC) feedstocks. Error was < 10% even for low concentrations (0.01 pg g-I) Samples treated with H,SO prior to ashing. Co was added as internal standard but corrections applied to compensate for overlap of Fe Ka on Co Kp. Good agreement obtained for NIST reference materials 0.5 p1 sample injected into a hot zone (Pyrojector 11) held at between 0 and 900 "C depending on solvent volatility.Vaporized sample fed straight to ICP torch; LOD=5 pg I-' As for Fe Commercial thermospray-membrane desolvation sample introduction system used with reversed-phase HPLC (C,*) for simultaneous measurement of Ni and V porphyrins in crude oil concentrates As for Fe As for Fe Calibration using aqueous standards; LOD= 3 pg g-' Speciation of porphyrins using HPLC-ICP-MS Determination of oxygenated additives in gasoline using GC-AES. Large variation in detector selectivity found depending on viewing position and support gas composition Collaborative study of standardized IUPAC method for direct determination of P in crude and refined oils and fats ( 1 -100 pg g-I) Speciation of alkyllead compounds using GC-ICP- AES Speciation of inorganic and trialkyllead chlorides using HPLC-ICP-AES or ICP-MS.Reversed- phase step gradient from 10 to 70% methanol used for ICP-AES but 30% MeOH isocratic separation for ICP-MS using AAS with C,H,-air flame at 2 17.0 nm. Suitable for determination of PbEt only; Pb concentration range 0.05-1.0 g I - ' Speciation of alkyllead compounds down to sub- ng g-I levels using capillary GC-ICP-MS Determination of organic lead in solid waste and soil by extracting with xylene; 1% absorbance = 0.20 Samples diluted with aviation fuel and Pb determined g-l Pb Review of GC-AAS methods for speciation of S simulated distillation using GC-AES Determination of sulfidic and thiophenic S contents using S K edge X-ray absorption spectroscopy.Results (after correction for inorganic S) compared well with X-ray photoelectron spectroscopy organolead compounds 921C700 921C3564 C Crude oil MS;-;G 921 1 607 Fe Crude oil Fe Heavy fractions Fe Crude oil and residues AE;MIP;G AA;ETA;L XRF-;L 9 113909 9211877 9213079 921C3489 Hg Light hydrocarbons MS;ICP;G Ni Crude oil Ni Crude oil AE;MIP;G MS; ICP; L 9 113909 921C454 9211877 9213079 9213 195 921C3473 921C3434 and 921C38 13 Ni Ni Ni Ni 0 Heavy fractions Crude oil and residues Crude oil Crude oil Gasoline AA;ETA;L X R F;-;L XRF-;L M S; I C P; L AE;MIP;G P Crude and refined oil AA;ETA;L 9212 54 7 9 1 lC3708 9 1 I3907 Pb Pb Gasoline AE;ICP;G AE or MS;ICP;L Alkyllead chlorides AA;FL Pb Petroleum fuel 9 1 I3934 Pb Alkyllead compounds Pb Alkyllead compounds MS;ICP;L AA;FL 92lC455 9211591 Pb Organolead compounds AA;F;G 9213 1 15 S Diesel fuel S Heavy fractionslasphaltenes A E; M I P;G X-ray absorption; - 9 1 lC37 I 9 9 113986358R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL.7 Table 2 SUMMARY OF ANALYSES OF CHEMICALS-continued Technique; atomization; analyte form* AE;MIP;G Element S S V V V V V V V V V V Various Various Various Various Various Various (wear metals) Various (additive and wear metals) Various Various Various Various (wear metals) Various Various Matrix Hydrocarbons Sample treatmentlcomments Comparison of AES and chemiluminescence for S- selective GC detection. LODs for both systems were 6-10 pg. However GC-AES gave better sensitivity and stability for carbon Identification and quantification of S classes e.g.sulfur sulfides thiophenes sulfoxides sulfones sulfinic acids sulfonic acids and sulfate As for Fe As for Ni Reference 92lC3123 9213856 9 113909 92lC454 92lC3472 921 1256 375 116 9211791 921 1877 9213019 9213 195 92lC3413 9 1 lC3157 911391 1 921236 92lC398 92lC502 92lC6 14 92lC65 1 92lC657 92lC706 921 1242 9211255 921 1680 921 1 193 9212719 Petroleum and source rocks X-ray absorption; - Crude oil Crude oil Crude oil AE;MIP;G MS;ICP;L M S; ICP; L Sample diluted with IBMK and V extracted into HNO,. Calibrated using standard additions; recovery 99- 10 1 % Oil sample (10-30 g) ashed at 550 "C then dissolved in 1 + 1 HCI (50 ml). V determined in 20 pl portion at 3 18.4 nm using Ar as carrier gas. LOD was 6.9 ng g-l Direct dissolution in xylene compared with wet and dry ashing procedures.Wet ash procedure (H20,-H,S04) gave low results. Results with xylene dissolution method in agreement with dry ash approach but much more rapid 0.5 ng g-I and RSD 1.06% at 1.10 pg g-' Direct analysis using La chemical modifier. LOD was As for Fe As for Fe As for Ni. LOD = 4 pg g-I As for Ni Use of an ultrasonic nebulizer for determination of Cu Fe Na Ni and V in crude oil after dilution with an organic solvent Trace metals measured using AAS with air-C,H flame. Use of organometallic standards eliminated in both cases Review with 93 refs. LODs below 1 ng g-' for elements free of isobaric and polyatomic ion interferences. 0 added to carrier gas to prevent cone blockage Flowthrough oxygen combustion AAS for determination of trace metals. RSDs better than 9.4Oh and recoveries 80- 103% system for wear metal analysis Samples diluted with mixed solvent or dry ashed.Comparison of ICP-AES and rotrode spark emission Crude and heavy oil AA;ETA;L 921 921 Crude oil AA;ETA;L Fuel oil AA;ETA;L AA;ETA;L XRF-;L XRF;-;L MS;ICP;L MS;ICP;L Heavy fractions Crude oil and residues Crude oil Crude oil Crude oil Crude oil AA;F;L Silicones Diesel fuel XRF;-;- MS;ICP;L Crude oil AA;FL Lubricating oil AE;ICP or spark;L Lubricating oil AE;ICP;L Samples diluted with solvent. Internal standard shown to be essential to eliminate viscosity effects Petroleum samples Crude oil and products MS;ICP;L M S; ICP; L Direct analysis using electrothermal vaporization for sample introduction to ICP-MS Samples introduced into ICP as oil in water emulsions.Accuracy and precision are within about 3% and LODs around 0.1 pg g-I Samples treated with concentrated H,S04 dried and ashed. Residue dissolved in HNO filtered and then made up to volume prior to determination of Al Cd Fe K Li Mn Ni Pt Sn and V Rapid digestion in a closed microwave system. Recoveries for Al Cu Fe Ni and Pb in 300 pg g-l NIST standard oil were 98-103% with standard deviations of 3- 14Oh Determination of Cu Fe K Na Ni and V poisons in fluidized cracking catalyst (FCC) feedstocks Direct analysis of solvent-diluted oil using TXRF for concentrations above 1 p g g-'. Low temperature plasma ashing used for lower concentrations. LODs were in ng g-I range for the latter Crude oil MS;ICP;L Lubricating oil AA;F;L Heavy fractions Oils and greases AA;F;L XRF;-;LJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL. 7 359R Table 2 SUMMARY OF ANALYSES OF CHEMICALS-continued Technique; atomization; analyte form* Element Matrix Various Petroleum related materials Reference 9213070 921307 1 9213072 9213073 3213074 9213075 9213076 9213078 9213080 9213 146 9213203 92lC33 16 92lC3469 9213 8 3 9 Sample treat men tlcommen ts Review (38 refs.) of trace metal analysis in petroleum and products Various Various Lubricating oil (wear metals) Various (1 8 ) Crude oil XRF;-;L or AE;ICP;L Comparison of wavelength dispersive XRF and ICP-AES AE;ICP;L Samples diluted in kerosene using Sc as internal Rapid (ten elements per minute) multi-element standard analysis of lubricating oils for up to 24 elements using automated sequential FAAS emission spectrometry.Differences attributed to viscosity and particle size effects Comparison between ICP-AES and rotrode spark Various Lubricating oil (wear metals) (additive and wear elements) (wear metals) (additive elements) Various (1 3) Crude and lubricating oils Various Lubricating oils Various Lubricating oils Various Lubricating oil and additives AA;FL AE;ICP or spark;L AE;spark;L Comparison of three techniques to improve detection and quantification of large wear particles. Ashing rotating disc electrode showed most promise WDXRF methods for determination of Ba Ca C1 Cu Mg P S and Zn. Similar to ASTM D4927 XRF;-;L XRF;-;L AA;F or ETA;L Review ( 15 refs.) of analysis of petroleum and Microwave digestion (1 20 W) using (1 + 3 ) HNO products using EDXRF and H,SO (25-30 min).Cr Cu Fe Mn Ni and V determined using ETAAS and Na and Zn using FAAS. Standard additions used for calibration Samples digested with H,SO for 10-20 min using microwave heating. Cu Fe Mo and Ni determined using AAS and improve performance particularly for volatile hydrocarbons Pyrolysis GC-AES for determination of As C Hg N 0 P S and Se compounds in petroleum precursor sediments. On-line derivatization was discussed with butylation of Se compounds as example Determination of As Hg Sb and Se after microwave digestion under high pressure (82.2 bar) of oily waste solvent extracts. RSDs were 5.4-6.6% and recoveries 89- 105% Ultrasonic nebulizer used to reduce solvent loading Review of AAS analysis of silicones (23 refs.) Various Crude oil Various Lubricating greases AA; F; L Various Petroleum and products AE; ICP ; L Various Kerogen AE;MIP;S Various Oily waste AA;ETA or Hy;L AA;F;L Various Silicones ORGANIC CHEMICALS AND SOLVENTS- Ag Drugs and surfactants 9213924 9212454 AE;ICP;L AA;ETA;S or L Indirect determination of amine hydrochlorides quarternary ammonium chlorides and some reducing agents by precipitation following addition of silver nitrate.Residual Ag measured using ICP-AES containing pharmaceuticals by decomposition in graphite furnace followed by AAS. Concentrations in ng g-I range reported (0.001-0.1 mol dm-,) and surfactants (1-2%). A 10-fold enhancement was observed for oxine or triethanolamine at pH 3 using ion pairing and ion-exchange chromatography with ICP-MS.The As"' AsV and dimethylarsenic species were completely separated within 10 min reversed-phase HPLC-ETAAS. Eluent continuously delivered through fused silica capillary at 0.6 ml min-I. Deposited for 2 s on L'vov platform at 150 "C Direct determination of A1 in alkaline earth Study of enhancement effects of organic reagents Speciation of ng g-I levels of arsenic compounds Speciation of arseno compounds using isocratic A1 Pharmaceuticals 9 113974 9 2lC4 5 8 92lC499 A1 As Organic reagents Dimet h ylarsen ic AA; F; L MS; I CP; L Dimethyl arsinate As AA; ETA; L 92lC739360R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL. 7 Table 2 Element Br Br Br Ca Cd Cl c1 CI c1 CI c o c o SUMMARY OF ANALYSES OF CHEMICALS-continued Matrix Halogenated dioxins and furans Sodium diclophenac Volatile halogenated hydrocarbons Fulvic acid Diethylcadmium Halogenated dioxins Non-volatile chlorocarbons and furans 1,3,5-triamino-2,4,6- trinitrobenzene (TABT) Volatile halogenated Pesticides hydrocarbons Cosmetics Pyrrolidin-I-yldithioformate Technique; atomization; analyte form* AE M I P ; L XRFi-i- AE;M I P; L AA;F;L AE;ICP;G AE;MIP;L AE; M1P;L M S; ICP; L AE;MIP;L MS; MI P;L AA;F;L AA;FG Cr Sodium dodecylsulfate AA;FL Cr Organic reagents AA; F L Cr Organometallic compounds MS;ICP;L cu Dimethoxydithiophosphate AA;F;L (DDTP) AA;F;L Sample treatmentlcomments Comparison of AES with electron capture for element specific GC detection. Sensitivity of GC-AED worse and some peak tailing was evident No special pre-treatment required Determination of halogenated C and C hydrocarbons in swimming-pool air by trapping on Tenax cartridges and analysing with GC- MIP- AES using a thermal desorption cold trapping injector Study of complexation of Ca and Fe with fulvic acids at various pH and meta1:fulvic acid ratios Determination of Cd in environmental samples following vapour generation using sodium tetraethylborate(rI1).LOD was below 1 ng ml-l but memory effects were a problem As for Br Use of moving band He MIP interface for element specific HPLC detection using AES. LC eluate deposited on moving polyimide or steel band dried and then flash vaporized into MIP 1 + 1 nitric acid and bomb-digested. Solution diluted to 100 ml and analysed using negative ion mode ICP-MS. Typical C1 concentration 0.3% mlm 0.25 g TABT added to 50 g de-ionized water plus 5 ml As for Br SFC-MIP-MS used to separate and detect mixtures of halogenated compounds and pesticides; LOD 3 pg Samples ashed dissolved in water and analysed using AAS.Recovery was 99.0% RSD 4.loh and LOD 0.1 pg g-1 On-line generation of chelate with pyrrolidin-l- yldithioformate followed by vaporization then atomization in a flame heated silica tube. The LOD was around 0.08 p g Enhancement effect (7.6-fold) when ethanol was used as solvent and sodium dodecylsulfate as carrier stream in FI-AAS determination of Cr As for Al. Cr enhanced 7.6-fold using sodium dodecyl sulfonate and alcohol as carrier for FIA-AAS (0.6 mol dm-3 HCI for Cr solution) SFC-ICP-MS. N,O used as mobile phase to avoid interference at mlz 52 from 40Ar1ZC Indirect determination of pesticide DDTP.Method based on formation of Cu(DDTP) complex extraction into CHCl back extraction with an ammonia buffer (pH 10) and determination of Cu using FI-AAS complexes of Cu and Pb from HN0,-HClO digests of plant material. Precision better and interferences less than when IBMK used foam fractionation using chelating surfactants. Concentrations ng ml-l -pg ml-I in aqueous solution Speciation of Cr organometallic compounds using c u Cyclohexanone Cyclohexanone used for extraction of APDC cu Chelating surfactants AA;F;L Cu concentrated 50-75-fold from aqueous solution by Eu Dimethylsulfoxide (DMSO) or Luminescence; Determination of small amounts of water in DMF dimethylformamide (DMF) laser;L (0.1-1 mol-Yo) and DMSO (0.1-5 mol-%) using luminescence lifetime measurements of Eu11' determination of Fell andlor Fell' pg per 1% absorption RSD (4% and recovery 97.8-99.I% Fe Pharmaceuticals AA;F;L and Comparison of AAS and XRF with other methods for Ge Herbal medicine AA; ETA$ Ni(NO,) used as chemical modifier. Sensitivity was 2 XRFi-i- Reference 9 1 /C3637 9 113889 92lC3433 9 114035 921C647 9 1x3637 9 11C3639 9212640 921C3433 921C3475 9 1/40 14 921C578 9 1/39 17 92lC458 92lC3450 9212678 92lC5 8 5 9211635 9212652 9 1/40 15 921 1 54JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL. 7 361R Table 2 SUMMARY OF ANALYSES OF CHEMICALS-continued Element Matrix Hg Medicine Hg Methylmercury compounds Hg Chemical waste Hg Methylmercury species I Alkyliodides K Butanol La Butyl acetate Technique; atomization; analyte form* AA;FL AA;quartz furnace;L AE;ICP;G or AA;cold vapour;G AE;ICP;L MS;ICP;L AA or AE;FL A E;I CP; L Mn Bis-2-ethyl hexylphosphoric AA;F;L Ni Pharmaceuticals AA;F;L Pb Cyclohexanone AA;F;L S Organic compounds AE;M I P;L acid s (Ba) Pol ysulfides AA;F;L Se Se Sn Sn Sn Sn Sn Organoselenium compounds AE;ICP;L or AA;ETA;L Alkylselenium compounds AA;ETA;L Organotin compounds AE;CCP;L Butyltin and cyclohexyltin AA;ETA;L compounds Alkyltin compounds AA;ETA;L Organotin compounds Organotin compounds Y Butyl acetate Yb Organic reagents MS;ICP;L MS; I CP; L AE;ICP;L AA;F;L Sample treatmentlcomments followed by 3 + 1 HN0,-HCIO,.Also simulation of stomach leaching with determination of Hg in leachate using cold vapour AAS Speciation of Hg and methylmercury compounds in aqueous samples by GC-AAS after ethylation with NaB(C,H,),. The LOD was 167 pg for CH,HgCl dithiocarbamates prior to extraction and analysis using HPLC.Detection using ICP-AES or AAS after generation of Hg vapour using sodium tetrahydroborate (111) Determination of methylmercury species using capillary GC with axially viewed ICP-AES detection. LOD was 3 pg of Hg capillary GC-ICP-MS AE signals of K (range 20-100 pg ml-I) in air-C,H flame Concentration of La by extraction from aqueous phase using I-phenyl-3-methyl-4-benzylpyrazolone and butyl acetate at pH 5.5. LOD=5.3 ng ml-I in aqueous phase nebulization using Triton X- 100 and excess water Sample decomposed with 1 + I HN0,-H2S0 Species stabilized by complexation with Speciation of alkyliodides at ng g-I levels using Study of enhancement effects of butanol on AA and Kerosene solutions formed into emulsions for direct As for Co.Recovery was 93.6% RSD 1.2% As for Cu Comparison of MIP-AES with flame photometric detection for S specific GC. The AES response was less compound specific and LODs were 100 times better Indirect determination of di- tri- and tetra-sulfides by cleavage of S-S bond with NaBH oxidation to SO,2- using boiling H,O,-HCl treating with excess BaZ+ and measuring residual Ba using FAAS chromatographies were used with ICP-AES or ETAAS detection for speciation of seleno compounds Speciation of dimethylselenium and diethlyselenium using GC-ETAAS with specially constructed interface; concentrations in the range 0.14-20 ng were reported Evaluation of capacitively coupled plasma (CCP) as detector for GC determination of organotin compounds Determination of alkyltin species extracted from marine samples using HPLC-ETAAS (C,* column).Comparison with HPLC-MS and GC-MS after methylation compounds in organic solvent. Greatest enhancement ( I 9. I ) obtained for PdCl,(CH,CN) at 10 pg ml-l Pd; LOD=O.l I ng of Sn Speciation of tetra- and tri-organotin compounds using SFC-ICP-MS. Biphenyl 30 column used with CO with and without modifier (methanol) as mobile phase Speciation of alkyltin compounds using LC-ICP-MS with lauryl sulfate as mobile phase and butyl bonded silica gel as stationary phase. Separation accomplished in 20 min with pg LODs Anionic reversed-phase and ion pairing Study of sensitivity enhancement by organopalladium As for La; LOD=0.28 ng ml-1 in aqueous solution As for Al.Signal for Yb enhanced 50-fold using a mixture of sodium dodecyl sulfonate and salicylic acid in 0.1-0.3 mol dm- HCl Reference 92lC503 92/25 17 92lC3493 9213820 92lC455 92lC528 9212244 921 I 704 9 1/40 I4 9 2 1 0 8 5 92lC3637 9211 12 92/C498 92/24 1 1 9113589 921230 9212164 92lC3474 92lC3 I4 1 9212244 92lC458362R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL. 7 Table 2 SUMMARY OF ANALYSES OF CHEMICALS-continued Element Matrix Technique; atomization; analyte form* Sample treatmentlcomments Various Surfactants AA;F;L Various Organometallic compounds Various Various Crude drugs XRF;-;S Various Diethylzinc AE;spark;S Various ( 1 1) Chinese traditional medicine AA or AE;F;L Various (20) Organic compounds MS;ICP;L Various Wine AE;ICP;L Various Deuterated derivatization AE; M I P;L reagents Various Organic reagents AF;I CP ; L Various Methacrylic acid M S; I CP; L Various (1 1) Organic compounds AE;F;L Various Pesticide residues AE;MIP;L Various Organic compounds AE; M I P; L (non- metals) Zn Bis-2-ethylhexylphosphoric AA;F;L As for Mn Various (1 5) Dodecylsulfate surfactants AA;F;L Study of the enhancement effects of dodecylsulfate acid surfactants in FAAS with an air-C,H flame.Also study of interference effects of 19 cations in presence of sodium dodecylsulfate Various Water miscible organic AE;ICP;L On-line concentration onto chelating resin followed by washing with ammonium acetate-H,O and elution into ICP using dilute acid.LODs below ng ml-I for Cd Co Cu Mn Ni V and Zn; 2 ng ml-I for Pb Various Halogenated compounds MS;M I P;L Speciation of halogenated organic compounds using HPLC-MIP-MS with C column 70% methanol as mobile phase and an He plasma operating at between 300 and 350 W surfactants in FAAS determination of organometallic compounds on metals profiles in panax ginseng and platycodon gra ndifIoru rn Sample ashed in a closed system with HN0,-H,SO (5+ 1). Resulting oxides mixed with 5% mlm NaCl and Al Bi Ga Ge Pb Sb and Sn determined using spark emission spectrometry Average recoveries 94- 105% Signal enhancements up to 600% observed for As solvents New model proposed for enhancement effect of Review of recent developments in speciation and Study of effect of vegetational period or parts of plant Au Hg Se and Te in presence of glycerol glucose or methane.No effect for other elements studied ( 1 5). Enhancement linked to ionization energy Samples diluted 1 +4 with water and aspirated into plasma directly using Babbington type nebulizer Simultaneous monitoring of C H D I and S using GC-MIP-AES for determination of impurities in CD derivatized immunoenhancer reducing gases on fluorescence intensities of Ca K Mg and Na Matrix effects caused by methacrylic acid solutions (1-10W mlv) could not be eliminated by optimization or use of internal standards. Standard additions recommended selective GC detection using a dual channel flame photometric detector Comparison of GC-MIP-AES with other element specific GC detectors for determination of 10 pesticides in I2 agricultural commodities. AES used for C CI F P N and S selective analyses specific detection with a microbore packed column SFC.Near-IR lines used for C1 and S and UV-visible lines for C and H. LOD=0.8 ng s-I for S Elemental response factors in GC-MIP-AES found to be independent of molecular structure within about 5% RSD for C N and F and 7 and 9% RSD respectively for C1 and 0 Study of effect of changing methanol concentrations on element response during gradient elution LC-ICP-MS using a direct injection nebulizer. Substantial element specific variations observed Determination of ng g-l levels of impurities in stated semiconductor grade solvent using ETV-ICP-MS Transition metals concentrated on chelation column and eluted with HNO prior to ICP-AES analysis Study of the effect of several organic reagents and Conditional acceptance algorithm for element Moderate power (500 W) MIP-AES for element Various Halogenated hydrocarbons AE;MIP;L (non- metals) Various Organometallic compounds M S;I CP; L Various I -methyl-2-pyrrolidone MS;ICP;L Various Pharmaceutical products AE;ICP;L Reference 921 1 704 9 113598 91x3739 9 113908 9 I I3922 9211 16 921320 921333 921338 921 I 240 92lC 1 946 9212526 9212422 92/26 10 9212658 9212 7 2 8 9212 9 7 2 92lC3432 92lC347 1 92lC3696 92lC3 7 7 3JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL.7 363R Table 2 SUMMARY OF ANALYSES OF CHEMICALS-conlinued Technique; atomization; Element Matrix analyte form* Sample treatmentlcomments Various Ethanol AE;ICP;L LODs improved 5- 1 0-fold by adding 95% ethanol to (rare earths) "C aqueous solution and desolvating aerosol at 300 Various Organometallic compounds M S; 1CP;L Small volumes (25 pl) of organic solvent injected into flowing stream (2 -4 ml min-I) of 2% nitric acid.Sub-ng ml-' LODs achieved when membrane desolvation device incorporated Various Kerosene AA;ETA;L Various Solvents AE;ICP;L Various Solvents AA;ETA;L Various Quaternary ammonium salts AA;FL Various Organic compounds AE;ICP;L Various Emulsions AA;FL Various Organic solutions AE;ICP;L Study of stability of Cu Fe Ni and Pb in kerosene with different complexation reagents and autosampler vials. Dithizone used for Cu and Ni and APDC-acidified H,O-propanol for Fe and Pb were between 0.5 and 90 ng ml-I for Al Cr Cu Fe Na Ni P Pb Si and Zn in xylene kerosene DIBK white spirit and ethanol toluene and xylene) and chemical form in determination of Cd Co Cu Fe Ni and Pb using ETAAS determination of Ag Cd Fe and Zn after extraction into IBMK or xylene in organic media using ICP-AES atomization processes in FAAS determination of Ca Cu Cr Fe and Pb in emulsified organic solvents solutions using ICP-AES.Includes discussion of formation of volatile chelates solvent extraction methods and use with LC Review (48 refs.) on fundamental aspects of effect of organic solvents on ICP High-efficiency r.f. generator gave improved performance for analysis of volatile solvents. LODs for Cd Cu Mn Ni Pb and Zn in methanol were 0.2-1 1 ng ml-* Study of the role of plasma-solvent interactions in incompletely desolvated droplets in the plasma.Consideration of implications for matrix induced errors in practical analysis placed between heated spray chamber and plasma torch. Comparison of direct nebulization with FI into less volatile carrier stream 0 added to auxiliary gas to aid oxidation. LODs Study of influence of solvent (IBMK butyl acetate Study of influence of quaternary ammonium salts on Review (96 refs.) on direct determination of elements Study of effect of surfactant and solvent on Review (77 refs.) on direct analysis of organic AE;ICP;L AE;ICP;L AE or MS;ICP;L Various Volatile organic solvents AE or MS;ICP;L Novel desolvation system utilizing Peltier cooling Various Solvents Various Volatile solvents Various Solvents INORGANIC CHEMICALS AND ACIDS- Ag Coal XRF;-;S Ag Silver halide emulsion SIMS;-;S microcrystals As Electrolytic copper AF;F;L As As Food grade phosphoric acid AA;ETA;L Yellow phosphorus AFHy;L Reference 9 1/38 I 2 921C393 921C345 1 921C567 921C6 13 921952 921 1436 9211 788 9212227 92/24 14 9212420 921C3628 921C3694 9213822 Coal was ashed prior to analysis; LOD of 0.3 ppm 9 11389 1 Direct analysis 9211 399 reported Sample solution treated with KI-ascorbic acid 921 1 799 solution to mask interference from Cu; AsV was reduced to Asrr1 by treatment with tartaric acid-saturated thiourea in 0.15-0.5 mol dm- H,SO or 0.3-1 mol dm- HCI Pd employed as a chemical modifier 0.1-0.3 g of sample dissolved in 15 ml of HNO and evaporated to fuming with 10 ml of H,SO,; the cooled residue was mixed with urea and diluted; an aliquot of this solution was mixed with a 20% HCI solution containing 5% ascorbic acid and 5% thiourea 921264 1 9213974364R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL.7 Table 2 SUMMARY OF ANALYSES OF CHEMICALS-continued Technique; atomization; analyte form* AA;F;L Element Matrix Ba Strontium nitrate Sample treatmenticomments 4 g of dried Sr(NO,) + 0.4 g of KCI were dissolved in 100 ml of H,O; the effects of matrix and flame composition were also reported (RCOCH,COCH,;R=C,H,,) employed for isolation of Be 250 g sample dissolved in 250 ml of H,O and boiled with 10 ml of HNO,( 1.4 g ml-I) and a 200 ml portion treated with 20 ml of I 1.3% diammonium hydrogen citrate 5 ml of 2% ammonium pyrrolidine- 1 -carbodithioate solution and 10 ml of CHCI,; the CHCI extract was then collected in 1 ml of HNO and the extraction was repeated twice with 5 ml of CHCI and finally into H,O Method based on sample decomposition with HCl in PTFE container and the resulting tetrachlorogallium was separated by extraction with diisopropyl ether Trace Cu was electrodeposited on a thin tungsten electrode which was then placed in a graphite cup atomizer single crystal was studied by SIMS; the use of the SIMS signal allowed observation of layer-by-layer film growth Combined /?-diketo liquid exchanger Growth of Co thin films on the (1 00) face of a Cu - Less sensitive Fe line (296.7 nm) employed to avoid contamination problems and dilution of samples; the matrix effects of selenate and sulfate anions were studied Samples introduced into the arc in a 1 + 1 mixture containing 0.15% La 0.3% Bi and 0.1% In as oxides; the Bi line at 278.0 nm was used as an internal standard 10 g of sample mixed with 30 ml of H,O and boiled for 5 min with 4 ml of 22% HCI and 3 ml of 10% NaClO then diluted to 100 ml and a 10 ml portion transferred into an aeration flask and treated with 3 ml of 10% hydroxlammonium chloride solution 60 ml of H,O and 2 ml of SnCI Samples suspended in H,O containing 0.02% sodium hexametaphosphate and Hg generated from HCl media by the addition of sodium tetrahydroborate; good aggreement with dissolution procedure with an LOD of 5 ng g-I Samples collected on cellulose filters; good agreement was obtained with a dissolution method employing detection by AAS Method developed for detection of P at sub-ppb levels in H F optimization of method to reduce molecular interferences As in ref.9212274 Pb separated from the matrix by lanthanum hydroxide coprecipitation. The conditions for separation and detection were studied in detail Pb extracted with APDC and NaDDC into IBMK- cyclohexane Method for the selective extraction of Pd in the presence of Pt using quinolin-8-01 and tributylphosphite in CHCI was reported Non-volatile residues formed from deposition of nanolitre aliquots of solution onto high-purity silicon wafers are analysed using a high- performance CAMECA IMS 4f ion microanalyser; S was determined at ppb levels Chemical generation of S as H,S; method based on the quantatitive reduction of SO,,- ion by NaI-HI-H,PO,; LOD of 3.5 ng ml-I S reported Reference 9113936 92lC795 9212274 9212856 9 113929 9211 555 921 I 160 921101 Be Coal fly ash AA;ETA;L Cd Sodium chloride AA;FL Cd Organogallium compounds AA;ETA;L cu High-purity potassium AA; ETA;S bromide c o Copper single crystal SIMS;-;S Eu Coal fly ash Fe Selenium sulfide IDMS;-;S AA;ETA;L Ga Carbonation products Hg Sodium chloride AE;arc discharge$ 921320 1 AA;Hy;L 9212276 Iron(Ir1) oxide and titanium oxide pigments A A;-;SI 92/26 16 Mn Airborne particulates XRF;-;S 92/70 P High-purity acids MS;ETV 1CP;L 92lC3626 Pb Pb Sodium chloride Lithium and lithium salts AA;F;L AA; H y ; L 921227 5 9212736 Pb Pd Sodium sulfite Copper anode slime AA;F;L AA;-;L 9213053 921C3587 S Semiconductor process solutions (ultrapure HCI) SIMS;-;S 54 67 9213 92lC3 S Gallium phosphide AE; 1 CP; LJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL.7 365R Table 2 SUMMARY OF ANALYSES OF CHEMICALS-continued Technique; atomization; analyte form* AA;ETA;L Element Se Se Sn Various (2) Various (6) Various Various (5) Matrix Coal fly ash Sample treatmentlcomments Standard HN0,-HClO digestion CdCI,-PdCl chemical modifier used; LOD of 7 pg ml-l reported precision and accuracy of the method determined for the analysis of NIST SRM 1633a HgC1,-PdCl ( 1 + 1 ) evaluated as chemical modifier; Acorbic acid evaluated as a chemical modifier 0.2 g of sample was dried (120 "C) and digested with one of a series of acid mixtures (tabulated) and the digest evaporated to near dryness; acidic H,O was added and the solution diluted to 100 ml Sample dissolved in HCl; wavelength selection was dependent on spectral interferences and required sensitivity Surface analysis with a Grimm-type glow discharge lamp used to analyse uranyl fluoride layers formed on nickel substrate after exposure to UF,; an in-depth profile of layer composition was obtained LA employed for the direct determination of trace elements in carbonate samples; multi-element synthetic standards were prepared as both pressed powders and fused-glass discs FI employed for sample introduction; both internal standardization and standard additions were used Barium hydroxide octahydrate was analysed for trace element impurities by FAAS ICP-AES differential pulse anodic stripping voltammetry and ion chromatography Method LODs range from 0.1 to 3 pg g-I Direct determination of trace metals in sulfur (1 -5 mg sample size).Calibration using aqueous standard provided a L'vov platform was employed; chemical effects due to sulfur removed by pre-heating the furnace to 120- 150 "C Sample solutions in 0.25 rnol dm- HNO contained I g I-' of sodium as ionization buffer. Interference of REEs was suppressed by addition of 5-sulfosalicylic acid Analytes (Ca Mg) were separated from the WO,*- matrix by adsorption at pH 7.5 by cationic- exchange resin (DOOI-ML) and eluted at pH 8.5 with 0.01 mol dm-I EDTA determination of trace element impurities in a variety of samples; LODs in the range 20-100 pg ml-I have been claimed Direct introduction of solutions of Rh compounds Solvent extraction of analytes with ( 1 -phenyl-3- methyl- 4-benzylpyrazolone-IBMK; recoveries ranged from 94 to 106% Performance of ICP-MS evaluated for trace element determination in a variety of reagents Use of a novel U-shaped d.c plasma source was assessed for the analysis of trace elements in high- purity materials plasma using FI; calibration was achieved using standard slurries of previously analysed samples TXRF has been applied to multi-element Samples suspended in water and introduced into the Reference 921171 I 92lC684 9212488 9211 14 921267 921328 Coal fly ash AA;ETA;L Boric acid Fly ash AA;ETA;L AA;F;L High-purity bismuth oxide AE;ICP;L Nickel substrate A E ; G D; S Carbonates MS;ICP;S 921945 Various (3) Concentrated phosphoric acid MS;ICP;L Various (10) Barium hydroxide AA;F;L or and ammonium nitrate AE;ICP;L 921 1 I97 921 1 820 Various ( 14) Lead-acid battery electrodes AE;ICP;L Various (5) Sulfur AA;ETA;S 9211 857 9212060 921223 1 Various (4) Ores AE;F;L AE;ICP;L Various (2) Sodium tungstate 9212449 Various Ultrapure reagents TXRF;-;L 9212778 Various Rhodium compounds Various (7) Alkali metal salts AE;ICP;L AA;F;L 9212564 9212575 Various Semiconductor-grade Various High-purity acids and reagents solvents M S; IC P; L AE;DCP;L 9212879 921298 1 Various (4) Iron oxide pigments AE;ICP;L 9213599 NUCLEAR MATERIALS- 237Np Uranium solutions M S; ICP; L 237Np extracted in a 1 rnol dm- HNO solution using thenoyltrifluoroacetone (0.5 rnol dm-') in xylene; re-extraction of 237Np in 10 mol dm- HNO and dilution of the aqueous phase to I mol dm- HNO prior to analysis simultaneous multi-element monitoring of solutions eluting from ion-exchange columns Photodiode array detector was employed for real time 92x34 19 237Np Spent fuel dissolver solution AE;ICP;L 9113981366R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL.7 Table 2 SUMMARY OF ANALYSES OF CHEMICALS-continued Technique; atomization; Element Matrix analyte form* Pu Uranium and thorium AE;ICP;L 230Th Uranium oxide IDMS;-;L U - AE;ICP;L 230Th Pure uranium compounds U - U Radioactive wastes REE Uranium Various (7) Waters and soils Various Actinide matrices Various Nuclear materials Various Uranium and plutonium Various (9) Uranium oxide Various ( 16) Uranium dioxide MS;ICP;L AE:laser;S MS;ICP;L AE;ICP;L MS; ICP; L MS;ICP;S MS;ICP;S L MS;thermal ionization;S AE;ICP;L AE;ICP;L Sample treatmentlcomments Study of spectral interference of Th and U on trace Pu determination Standard sample of uranium oxide spiked with 230Th; analyte separated from matrix by ion exchange Optical emission spectra from high purity normal isotope abundance U generated with a glovebox enclosed ICP; spectral library of U lines from 197 to 700 nm given Simple anion-exchange separation Study of time-resolved emission from the plasma induced by laser ablation of U samples Development of sample dissolution and analyte separation procedures for several sources of wastewater samples Two step liquid-liquid separation procedure in which analytes were complexed with But phosphate in a CC1 medium; final traces of U were removed from the aqueous phase using tri-n- octylphosphine oxide; recoveries were reported to be in the range 90-103% while LODs varied from 0.1 to 9.5 ng ml-' ultrasonic nebulizer was used for the determination of long-lived radionuclides LA-ICP-MS employed in Q-switched mode for the analysis of a variety of SRMs; analyte sensitivity and relative response factors were calulated for common analytes in each matrix natural impurities in non-irradiated fuels fission products spent fuel and reprocessing solutions Complete sample volatilization while simultaneously integrating the signal for each isotope virtually eliminates effects of isotope fractionation in the evaporation process trialkylrnethylammonium chloride-polytrifluoromonochloroethylene (Kel-F) stationary phase Analytes separated from matrix by extraction on TBP levextrel resin column using 3 mol dm-3 HNO as the eluent; the matrix was retained on the column and the analyte elements determined in the eluent High-resolution ICP-MS system combined with an Methods have been developed for the analysis of Analytes separated from matrix using Reference 9 1 I3948 921 1 169 921 1 86 92lC384 9212784 92lC3740 9211717 9113587 92x347 92x350 921 1 004 921 1 804 9212963 * Hy indicates hydride generation and S L G and SI signify solid liquid gaseous or slurry sample introduction respectively. Other abbreviations are listed elsewhere.application provided that an optimum plasma viewing position and support gases are used. Even when chemical speciation is not specifically required problems can arise if analyte compounds are present in the sample in a volatile form.In these cases selective volatilization during sample nebulization can lead to erroneous results. However injection into a GC type injector causes complete vaporiza- tion of the sample thereby eliminating the problem. Beeren et al. (92/C3489) have used such an approach for determi- nation of organomercury compounds at ng g-' levels in light hydrocarbon matrices using a hot injector connected to an ICP-MS instrument via de-activated fused silica tubing (0.53 mm i.d.). The LOD was approximately 5 ,ug 1-I for a 0.5 p1 injection. Determination of toxic metals in solid and oily waste is an area of increasing concern in terms of environmental impact. Methods have been described for the determination of organolead compounds in solid waste by extraction with xylene and determination by FAAS (92/ 159 1) and for the determination of As Sb and Hg in oily waste using HG or cold vapour techniques following high pressure (> 82.2 bar) microwave digestion (92/3839).A method for the determi- nation of stable carbon isotope ratio analysis on single components in crude oils by direct GC-isotope ratio mass spectrometry (92/1607) may also be of interest. 2.1.2. Lubricating oils Determination of additive elements (Ba Ca C1 Cu Mg P S and Zn) in lubricating oils is routinely carried out in many laboratories throughout the world and standard American Society for Testing and Materials (ASTM) and Institute of Petroleum (IP) methods exist for this type of analysis using XRF ICP-AES and AAS.However readers may be interested in two reviews that have been published detailing methods used in the laboratories of two major oil com-JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL. 7 367R panies (9213072 92/3078). For smaller blending plants the method of choice is often AAS using an N20-air-C2H2 flame (e.g. IP 308). Xueming (92/C3564) has shown that comparable performance can be achieved for the determi- nation of Ba in lubricating oils with an air-C2H2 flame using a mixture of sodium dodecylsulfonate and benzyltri- methylammonium chloride as enhancing agent. If wear metals are to be determined in addition to additive elements then the most commonly used technique is ICP-AES. Again standard methods (e.g.ASTM) exist for these determinations. However the current ASTM methods are very general and do not specify key experimen- tal parameters dilution factor use of internal standard use of peristaltic pump type of nebulizer etc. Jansen et al. (92/C657) have shown that oil additives particularly viscosity index (VI) improvers can have a large effect on nebulizer efficiency and hence analytical results. It was shown that these effects can largely be eliminated by diluting the sample sufficiently and utilizing an internal standard. It is to be hoped that standard methods will be tightened to ensure that such interference effects are eliminated. These workers also studied the effect of wear metal particle size. With normal engine wear metal particle size was found to be less than 1 pm which is well within the range of the ICP technique (up to 10 pm).However ICP- AES is not suited to off-site use such as is required for many military applications. For these a rotating disc electrode spark emission spectrometer has been shown to be more suitable (92/C6 14 92/C65 1). Unfortunately this latter approach is more prone to viscosity effects necessitating that separate calibrations are established for each grade of oil to be analysed (92K3075). Whereas ICP-AES is limited to normal wear application in which wear metal particle size is at most a few pm spark spectrometers have been shown to be capable of detecting identifying and character- izing wear particles up to 40 pm in size (92/3076) allowing less normal wear processes to be identified and studied.If even larger wear metal particles are of interest then it may be necessary to digest the sample completely. Methods based on microwave digestion have been reported for the determination of wear metals in engine oil (92/1680) and lubricating greases (92/3203) using AAS. Very low concentrations of elements in lubricating oil (down to ng g-l) have been determined using TXRF after ashing the prepared sample reflectors in a low temperature oxygen plasma (92/2779). It will be interesting to see what additional information can be provided about wear pro- cesses from the low concentrations of wear metals that would not normally be detected using conventional ap- proaches (early wear detection wear characterization from minor alloy components etc.).Two reviews have been published on atomic spectro- metry of silicone lubricants (92/3924) and X-ray methods for silicone analysis (92/236) and an application of dynamic SIMS to the study of silicone release coatings has been reported (921 1 400). 2.2. Organic Chemicals and Solvents This section of the review covers the analysis of organic chemicals reagents and solvents. Also included is work in the rapidly growing field of chemical speciation of elements. Methods involving preconcentration by extraction into organic solvents are not specifically included since most are used for the analysis of high-purity inorganic compounds or nuclear materials and so are reported in the appropriate sections of the review. The format is essentially the same as in previous years (see J.Anal. At. Spectrom. 199 l,6,283R). A summary of work during the review period concerned with the analysis of organic compounds and solvents is given in Table 2. 2.2.1. Chemicals As with the analysis of petroleum products by far the most rapidly growing area in the field of organic chemicals analysis is that concerned with elemental speciation. One of the biggest growth areas is in the field of environmental analysis since it is well known that certain elemental forms can be extremely toxic while others are relatively innocu- ous. However elemental speciation is equally important in industrial analysis since the ability of a contaminant to poison a catalytic process can also depend on chemical form and the ability to devise processes to remove undesirable contaminants also requires knowledge of the specific chemi- cal forms present.Recent developments in speciation and determination of organometallic compounds in environ- mental samples have been reviewed by Chau and Wong (92/ 1 1 6). The largest number of papers on elemental speciation have been concerned with GC-MIP-AES reflecting the wider availability of robust commercial instruments (91/C3637). The technique can be used in a synergistic combination with GC-MS the latter technique providing compound confirmation and the former providing elemen- tal ratios to aid interpretation of the mass spectrum (92/C3761). This approach has been used to identify impurities in a CDJ derivatized immuno-enhancer (so- dium dithiocarb-imuthiol) and aid GC-MS interpretation of results (92/2526).A comparison has been made of the performance of helium MIP-AES relative to other element selective GC detectors for the analysis of pesticide residues (9212728). It was reported that MIP-AES was the only detector which was suitable for the determination of C1 F and P containing pesticides in all agricultural commodities studied. Specific advantages of MIP-AES indicated in- cluded good specificity and uniformity of response irrespec- tive of chemical structure. Kovacic and Ramus (921C3432) have reported that for a series of halogenated compounds (aromatic aliphatic and heterocyclic) response factors for C N F C1 and 0 were independent of structure within experimental error (about 5% RSD for the first four elements and 9% RSD for 0).Compound independent calibration could therefore be used when individual stan- dards were unavailable or when a large number of analytes had to be quantified quickly. Applications of the use of GC-MIP-AES have included the determination of volatile halogenated hydrocarbons in a public indoor swimming pool air (921C3433) and quantification of polychlorinated dibenzodioxins and polychlorinated dibenzofurans (92/25 3). Whereas non-polar compounds can be analysed directly polar and ionic compounds generally require derivatization to facilitate GC analysis. Rapsomanikis and Craig (92/25 17) have utilized in situ derivatization with NaB(C,H,) for the determination of ionic methylmercury compounds using GC with a quartz furnace AAS detector. A problem which can arise if MIP-AES is used for GC detection of organometallic compounds is that these materials can deposit on the discharge tube walls and later be displaced by hydrocarbon species giving rise to spurious peaks in the element specific chromatograms.One approach to eliminating this problem is the use of a CCP in place of the MIP. Huang and Blades (92/3589) have utilized such a plasma for speciation of orgunotin compounds with LODs of around 0.1 ng s-l. For organometallic compounds and heavy halogens the ICP can also be utilized for element specific GC detection. Kato et al. (9213820) have reported the determination of methylmercury species by capillary column GC with axially viewed ICP-AES detection. The LOD was calculated to be 3 pg as Hg. However approxi- mately two orders of magnitude better sensitivity can be achieved by utilizing ICP-MS as a capillary GC detector (92/C455).In the latter work a novel heated torch was used368R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL. 7 to prevent condensation of higher boiling compounds in the ICP torch injector. Good recovery was obtained for compounds with boiling-points in excess of 320 "C. Other novel approaches reported for element specific GC were combination with ETAAS (92124 1 1); injection of organic vapours into a running hollow cathode discharge (9 1/38 10); and use of a dual-channel flame photometric detector with a conditional access algorithm (92/2658). Non-volatile compounds such as most inorganic and ionic forms are generally not amenable to speciation using GC.In these cases some form of liquid chromatography is therefore required. Several forms of liquid chromatography can be used; normal phase; reversed phase; ion chromato- graphy; size exclusion; supercritical fluid etc. A compre- hensive review has been published covering metal specia- tion using various types of liquid chromatography with atomic spectroscopic and other forms of detection (9212599). Atomic emission spectrometers utilizing plasma sources have been extensively used over the years as element specific HPLC detectors. However this approach may have reached maturity since this year has seen fewer reports of applications of this type. Two notable exceptions were the speciation of Hg in chemical waste using HPLC-ICP-AES (92/C3493) and the determination of As- and Se-containing compounds using HPLC with an alter- nating current plasma (ACP) detector (91K3638).In the former application species were stabilized before extrac- tion by complexation with dithiocarbamates. In both cases analytes were introduced into the plasma using post- column vapour generation with sodium tetrahydrobor- ate(II1). Although sensitivity for elements that can be introduced into the plasma in vapour form is generally adequate for most applications sensitivity can be limited if the analyte must be introduced using solution nebulization. In these cases use of ICP-MS rather than ICP-AES can be beneficial. Fischer and Boender (921C499) have reported speciation of As and Se using ion chromatography with ICP-MS detection. Thus A P AsV and dimethylarsenic acid were completely separated in 10 min with LODs ranging from 1 to 5 pg 1-l.Application of LC-ICP-MS (butyl bonded silica gel-lauryl sulfate) has also been reported for speciation of six organotin compounds with LODs in the picogram region (921C3741). For LC-ICP-MS sensitivity and peak dispersion can be improved using a low dead volume direct injection nebulizer. However Houk et al. (92/C3471) have shown that although this system tolerated volatile solvents such as methanol or acetonitrile analyte sensitivity varied substantially from element to element when solvent gradients were used. This might limit applications of this approach to cases when mild solvent gradients can be used. An alternative approach to improv- ing sensitivity is to use ETAAS as an element specific detection system for HPLC.Such an approach has been used for quantification of butyltin species in marine samples (921230) and for speciation of As compounds (92K739). However the duty cycle of the furnace is typically about 40 s which restricts the speed at which data points can be acquired. For speciation of non-metals the ICP is not a suitable plasma source in view of the inability of argon plasmas to ionize elements with higher ionization potentials efficiently. For these elements the helium MIP is generally preferred. Caruso et a/. (9 113908) have used a 500 W helium MIP-MS with reversed-phase HPLC (70% methanol mobile phase) for speciation of halogenated organic compounds. Detection limits were reported to be 50 1 and 10 ng respectively for Br I and C1.Supprrriticalfluid chromatography has attracted increas- ing interest over recent years in view of its ability to allow speciation of non-volatile and thermally labile compounds often with greater speed and resolution than HPLC. Caruso and co-workers have reported application of SFC-MIP-MS for characterization of Cr compounds (92/C3490) organo- tin species (921C3474) and pesticide mixtures (921C3475). The coupling of a microbore packed column SFC with a moderate power (500 W) MIP-AES system has also been described (9212972). Lines in the UV1VIS region of the spectrum were used for C and H but near-IR lines were used for C1 and S. It was found that molecular band interference was a problem in the UV/VIS region with both COz and N20 mobile phases but the near-IR region was affected only As in previous years studies of sensitivity enhancement caused by organic compounds and surfactants in atomic spectrometry has received considerable attention over the review period.Wei et al. (921C458) have reported enhance- ment factors of 10 7.5 and 50.7 respectively for the determination of Al Cr and Yb using FAAS with a C2Hz flame Reagents used were oxine (Al); alcohol + sodium dodecyl sulfate as carrier for FI (Cr) (9 1/39 17); and salicylic acid + sodium dodecyl sulfate (Yb). The influence of different cations on the enhancement effects of dodecyl sulfate surfactants in the determination of 15 elements by FAAS has been studied by Pharr et al. (9113598) and a novel surfactant enhancement mechanism has been pro- posed (9 113922).Organic compounds and surfactants have also been shown to have a significant effect in ICP spectrometry (921 1240 9212422 92/26 10 921C377 1). In particular it has been shown that signal enhancements of up to 600% can be observed for the determination of As Au Hg Se and Te in the presence of glycerol glucose or methane (92/1240) using ICP-MS. No effects were ob- served however for most other elements. The effect appeared to be linked to ionization energy and was most pronounced between 9 and 11 eV. Such problems have led Marshall and Franks (9212610) to recommend use of standard additions to avoid calibration problems in the analysis of methacrylic acid solutions by ICP-MS. Two novel sensitivity enhancement systems have been reported based on vapour generation techniques.Mir et al. (921C578) have reported a detection limit of 0.08 pg for the determination of Co by AAS (flame heated silica tube atomizer) using on-line generation of its chelate with pyrrolidin-1-yldithioformate while Manzoori et al. (921C647) have reported the determination of Cd by ICP- AES. Several indirect methods have been reported for the determination of organic chemicals and other molecular compounds using atomic spectrometry. The pesticide dime- thoxydithiophosphate (DDTP) has been determined using FI-AAS with liquid-liquid back extraction (9212678). The method was based on the formation of the CU(DDTP)~ complex extraction into chloroform and back-extraction using an ammonia solution buffer (pH 10). Flame AAS has also been used for the determination of di- tri- and tetra- sulfides following cleavage of the s-S bonds using NaBH with AlC1 and NH4C1 catalysts oxidation of the produced thiols to and treatment with excess of Ba2+ (921112).The unconsumed Ba was determined using FAAS with an N,O-C2H2 flame. Indirect methods for the determination of some chloride containing drugs and surfactants using ICP-AES have also been discussed (9212454). The methods which are based on precipitation of silver chloride are claimed to exhibit superior accuracy and precision than titrimetric or FAAS methods. by N2O. 2.2.2. Solvents As in previous years most of the work over the review period has concentrated on the effect of organic solvents on ICP sources for AES and/or MS. Three review articles have been published (9211 788 9212414 9212420) that deal with fundamental effects of solvents on ICP discharges optimi-JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL.7 369R zation analytical characteristics and applications (includ- ing extractions and coupled HPLC). Fundamental studies have been carried out on the effect of solvent and solvent load on the ICP discharge both macroscopically and around incompletely desolvated droplets (9213396 9213694). It was noted that the magnitude and direction of matrix effect errors can be affected by plasma-solvent interactions in these latter regions of the plasma. Analysis of volatile organic solvents is particularly difficult using ICP techniques since the high solvent load produced normally leads to thermal quenching of the plasma.Tyler et al. (921C3628) have shown that this problem can be reduced by using a high-eflciency r.f generator. These workers claimed LODs for methanol that were an order of magnitude better than other published data. Nevertheless band interference from molecules such as C2 and CN can still be a problem and so addition of oxygen to the auxiliary gas flow to aid combustion of organic species is still beneficial (921C6 13). However in view of the matrix effects that can arise from incompletely desolvated aerosol dro- plets and problems that can occur with polyatomic ion interferences in ICP-MS it is generally better to remove as much solvent as possible from the aerosol prior to introduc- tion into the plasma. Ebdon and co-workers (921C393 921C345 1 9213822) have described two desolvation de- vices for the analysis of particularly volatile solvents using ICP-AES or ICP-MS.The first of the devices was based on a heated spray chamber and Peltier cooled condenser while the second made use of a membrane separator for desolva- tion. In both cases improved results were obtained by FI of 25-50 p1 of the volatile sample into a less volatile carrier stream (2-ethoxyethanol or dilute HNO,). This approach was used for analysis of reactive organometallic species such as trimethylgallium and methyllithium. An alternative approach for water miscible volatile organic solvents has been described in which transition metals are removed from the solvent (on-line) onto a chelating resin washed with ammonium acetate solution and then eluted into the plasma with dilute HN03 (9 lK3739).A particularly interesting application of ICP-MS with organic solvents has been described in which solvent (octanol) filled dialysis sacs were placed in water or sediments for extraction of organometallic pollutants (921C3494). The effect of organic solvents on ETAAS has also received some attention over the review period. Unlike FAAS in which the effect of organic solvents can be advantageous owing to improved nebulization efficiency with ETAAS the effect is usually detrimental. Tserovsky and Arpadjan (921952) have studied the behaviour of Cd Co Cu Fe Ni and Pb in various organic solvents (those commonly used in extraction methods) during analysis by ETAAS. The influ- ence of the nature of the solvent complexing agent atomizer type chemical form and amount of modifier were studied and optimum conditions established.With analysis by ETAAS the relatively long analysis times usually necessitate use of an autosampler if large numbers of samples are to be analysed. However for organic samples problems may arise due to adsorption of metals on the vessel walls. Curtius et al. (921C567) studied the stability of metals in kerosene as functions of ligands and vial material. For Cu and Ni the complexes with dithizone were stable for at least 40 min using polyethylene vessels whereas for Fe and Pb the best stability (3 h) was obtained by mixing the organic solution containing the ammonium pyrrolidin- 1-yldithioformate complexes of the metals with acidified water and adding enough propan- 1-01 to make a one-phase solution.Vessels made of PTFE were best for Fe and quartz vessels for Pb. Sensitivity enhancement of 19-fold were reported for the determination of alkyltin compounds in organic solvent by ETAAS using 10 pg ml-' of Pd added as PdCl,(CH,CN) (9212764). Of the solvent extraction methods used for sensitivity enhancement Radecka and Radecki (921C585) have shown that cyclohexanone gives superior performance to IBMK for the extraction of Cu and Pb as their APDC complexes while Chen et al. (9212244) have reported enhancement factors of 3.6 and 11.9 for the determination of La and Y respectively by ICP-AES and extraction with PMBP ( 1 -phenyl-3-methyl-4-benzylpyrazolone)-acetate at pH 5.5. A novel preconcentration technique has been reported by Garip and Thompson (9211635) in which transition metal cations could be concentrated from aqueous solution by foam fractionation using chelating surfactants. A 50-75- fold increase in concentration was reproducibly achieved for solutions containing Cu in the ng ml-1 to pg ml-1 range with determination by FAAS.2.3. Inorganic Chemicals and Acids 2.3.1. Chemicals As with previous ASU reviews a significant number of abstracts were received concerning the application of atomic spectrometric techniques to the analysis of samples containing high dissolved solids. In the chlor-alkali industry the transition from traditional mercury cells to new membrane cell technology for the electrolysis of brine has placed more stringent demands on the required purity of brine feed stocks.Trace level impurities can quickly cause blockage of cell membranes which leads to reduced cell efficiency and ultimately to costly replacement of mem- branes. High solids analysis has traditionally been a problem when using ICP-AES. Despite improvements in nebulizer designs to address this problem at very high salt concentrations these nebulizers may still suffer from block- ages. An evaluation of the performance of several nebulizer designs applied to the analysis of high dissolved solids has recently been presented (921C3764). Concentric C-type and Babington V-groove set-ups were examined and the effect of sample bore size and nebulizer geometry assessed. A standard high precision concentric nebulizer in series with a high solids accessory was also employed in combination with a multi-channel polychromator for simultaneous multi-element analysis of concentrated salt solutions.The high solids accessory allowed a continuous flow of rinse solution to the nebulizer and spray chamber. The sample was introduced in 100 pl slugs to this rinse system. This enabled the sample introduction system to be continuously flushed preventing blockages. In contrast another applica- tion reported that the use of a wide bore injector tube combined with the use of humidified argon allowed saturated brine solutions to be nebulized in a stable manner for hours without the need of a high solids nebulizer (911C3741). Detection limits in the low ppb range were claimed using this procedure. Other applications to brine analysis received in this review period included the deter- mination of iodide and iodate by helium MIP (91/3971) and the analysis of heavy metal impurities by FAAS following an extraction procedure (92/40 16).Direct analysis of sea-water using electrothermal vapori- zation into an ICP has also been reported (921C3293). The transport efficiencies of elements of interest were deter- mined by collection of the aerosol exiting the injector tube on a series of stacked depth and membrane filters. Analyte transport efficiencies were typically greater than 50%. Attempts were also made to correlate matrix effects with variabilities in sample transport morphological differences in the aerosols and excitation potentials of the analytical lines of interest. The use of ETAAS combined with chelation ion exchange has also been applied to the analysis of sea-water (921C3704).Preconcentration and matrix elimination was achieved by the use of a Dionex chelating resin (Metpac-CC1) in an off-line mode. A series of papers370R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL. 7 detailing methodology for the analysis of sodium chloride by FAAS have been published by the British Standards Institution. Methods for Cd (92/2274) Hg (92/2276) and Pb (92/2275) have been described. In each case trace metals were separated from the salt matrix by solvent extraction. The analysis of lithium salts has also received attention. Lead was determined in lithium and lithium salts by HG- AAS following a lanthanum hydroxide co-precipitation separation procedure (92/2736).In addition Ca and Mg were determined by FAAS following extraction from the matrix by PMBP-IBMK at pH 7.2. The requirement to provide high-purity chemicals and reagents for a wide variety of industries has resulted in an increased demand for trace level determinations in these materials. This is evident in the present review by the increased number of abstracts received relating to the analysis of high-purity chemicals. Thus FAAS ETAAS and ICP-AES have been applied to the determination of impurities in vanadium disilicate and vanadium pentoxide (9212485). The matrix was removed by ion-exchange separation after converting the vanadium into an anionic Vv peroxide complex. An ETAAS method has been reported for the determination of Fe in selenium sulfide; magnesium and nickel were employed as chemical modifiers.Trace amounts of Re have been measured in copper sulfide samples by ICP-AES (92/2935). Two differ- ent methods of sample decomposition were employed oxidative alkali fusion and acid dissolution. A combination of ICP-AES differential anodic stripping voltammetry and ion chomatography were employed for trace element analysis of barium hydroxide (92/ 1820). The analytical procedures employed were discussed with respect to matrix interference effects. The rapid determination of trace metal impurities in high-purity bismuth oxide by ICP-AES has also been reported (92/267). Other applications published in the year under review included the determination of Ca and Mg in sodium tungstate by ICP-AES (92/2449) Cu and Ni in pure barium nitrate (92/2737) Cu in highly pure potassium bromide by ETAAS (92/3929) and Ba in stron- tium nitrate by FAAS (9113053).Ultra-pure chemicals such as mineral acids ammonia solution hydrogen peroxide and organic solvents are applied in different process steps in the semiconductor industry (see also section 3.2 of this review). The higher the integration density of the chip production the more the chip yield is limited by extremely low trace element contamina- tion of the applied process solutions. Suppliers of electronic grade chemicals must guarantee maximum trace levels of up to 40 elements in the lower ng g-l range. Considerable effort has been expended to develop methods of analysis to meet these exacting requirements. A review of the perform- ance of ICP-MS applied to the direct analysis of semicon- ductor-grade reagents has been published (9213064).Micro- volume SIMS has been applied to the determination of non- volatile S residues in semiconductor process solutions (92/3 1 54). Residues formed from the deposition of nano- litres of samples were analysed by dynamic SIMS which offered the capability to detect and quantify S in ultrapure HCl solutions used in gallium arsenide wafer fabrication. High-purity corrosive gases used in semiconductor manu- facturing present problems not only in production storage and handling but also with regard to sampling and trace element analysis. A method has been described for the sampling and analysis of hydrogen chloride for trace metal impurities (92K3389).A method for the determination of Si in ultra-pure acids using ETAAS has been reported (92/C375 1). Problems due to contamination were controlled by operating with clean rooms (class 10000) and clean bench (class 10) facilities. Under these conditions it was shown to be possible to determine Si in aqueous solutions free from environmental contamination. In some cases the LODs available with state-of-the-art techniques are not sufficient for some semiconductor applications. In such cases some form of preconcentration or enrichment step is required prior to analysis. A new closed apparatus for the evaporation of samples for preconcentration of sample solutions used primarily in semiconductor production has been described (92/36 15). The principle is comparable to sub-boiling distillation.The sample was heated from above using an IR heater and the vapour produced condensed at a cold finger and the condensate collected in a U-shaped glass tube. The system has been used for the evaporation of ultrapure water HC1 HN03 H,SO and ammonia solution samples. Using this apparatus ETAAS detection limits of 0.05 ng g-1 were reported even for ubiquitous elements such as Ca Fe and Na. Atomic spectrometric techniques continue to be widely applied in the electroplating industry for the analysis of electrode materials plating bath solutions and waste pro- cess streams. Thus FAAS has been applied to the determi- nation of heavy metals present at high concentrations in electroplating waste sludges (9212576). The use of ICP-AES for the determination of 14 trace element impurities in Pb-acid electrodes has also been reported (921 1857).Impurities in carbon anodes employed for the electrolysis of aluminium have been determined by AES (9212263). Other reported applications included the determination of Pd in copper anode slime (92/C3578) major and minor trace elements in plating solutions by FAAS and chrome in chrome-acid plating solutions by flame emission spectro- metry (9213790) and Mn in airborne particulates in a dry- cell battery factory by XRF (92/70). A significant increase in the number of abstracts relating to the analysis of coals and fly ash was observed compared with previous reviews. This undoubtedly reflects increased environmental awareness and more stringent controls on power station emissions.A rapid and accurate method for the determination of major and minor elements in coal by ICP-AES with slurry sample introduction was described (92/305). Optimization of slurry preparations such as optimum coal and surfactant concentrations and sample grinding regimes were reported. Also ETAAS was em- ployed for the determination of Se in coal fly ash (92/C684). A mixed mercury-palladium modifier was employed and the validity of the method assessed by analysis of NIST SRM 1633A Coal Fly Ash. In an alternative method Se was determined in coal fly ash by ETAAS employing a conven- tional HN03-HC104 sample dissolution. A cadmium-pal- ladium modifier was employed in this case. Using this procedure no spectral interferences were reported from iron or chlorine and an LOD of 7 pg 1 - I was achieved (92/17 1 1).In another application SIMS X-ray microanalysis and SEM were used to investigate the surface characteristics and depth profiles of coal fly ash (92/1561). Coal fly ash particles were size fractionated magnetically separated and mounted in a 6 mm diameter holder. Large particles (100 pm) were then analysed. Other applications reported were mineral speciation of Cu and Zn in fly ash using FAAS (92/114) determination of Be in fly ash by ETAAS following a liquid chelating extraction procedure (92/C795) and the determination of trace amounts of Eu in coal by isotope dilution-MS (921 1 160). Laser ablation ICP-MS has been applied to the analysis of carbonate materials (92/945). Multi-element synthetic stan- dards were prepared as both pressed powders and fused discs.The elements Ba Mg Mn Pb and Sr were added to the pressed powder standards and these elements together with U were added to the fused discs. Calibration graphs for both synthetic standard types were linear over three orders of magnitude but the fused disc standards gave more precise results. The accuracy of the technique was assessedJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL. 7 371R by the analysis of SRMs. Other articles of interest received during the period under consideration included a review of inorganic MS in agriculture (92135); determination of trace elements in phosphate fertilizers and animal feeds by ICP- MS (9113667); the determination of Cu Cr Mn and Zn in iron oxide pigments using FAAS with FI slurry sample introduction (9 113599); and a cold vapour atomic absorp- tion method for the determination of Hg in iron(I1) oxide and titanium oxide pigments employing slurry sample introduction (92/26 16).A review examining future trends in the application of XRF in the cement industry was also published (9211 930) 2.3.2. Acids There have been fewer abstracts received relating to the analysis of acids in the year under review (although there is a degree of overlap with abstracts relating to the analysis of semiconductors) Total reflection X-ray spectrometry has been applied to the analysis of a number of ultrapure acids (9212778). This technique would seem to be ideal for this type of application in that it offers a rapid and sensitive method of analysis with minimum sample preparation.Thus a 100 pl volume of sample was sufficient for complete multi-element coverage. Detection limits in the range 20- 100 pg ml-I have been obtained. Using preconcentra- tion procedures LODs below 5 pg ml-l have been claimed. The reliability of the sample preparation procedures and the accuracy of the technique were assessed by independent analysis of duplicate samples using ICP-MS. An ETV-ICP- AES method for the determination of P in HF has been reported (921C3626). Data were presented on the optimiza- tion of the method to reduce polyatomic interferences and an LOD of 1 pg 1-l was claimed. The determination of Ge Pd and Pt in highly concentrated solutions of H3P04 and NH4N03 by ICP-MS using FI sample introduction has been reported (92/ 1 179).It was reported that selection of sample and skimmer sets together with the use of two isotopes per element for measurement minimized interference effects. Both internal standardization and the method of additions were used. The use of a U-shaped d.c. arc plasma source in the determination of trace elements in high-purity acids and solvents by AES has been described. The technique has been compared with ICP-AES (921298 1). The determina- tion of As in food-grade H3PO4 by ETAAS using Pd as a chemical modifier was reported. (92/264 1). 2.4. Nuclear Materials Analysis using atomic spectrometry continues to play a vital role in all aspects of the nuclear industry from nuclear fuel fabrication to monitoring and quantifying waste products prior to disposal.The ability to provide both elemental and isotopic information at trace levels makes ICP-MS an invaluable tool in the nuclear field and the growing number of reported applications provide evidence of its acceptance within this industry. However the methodologies employed for the analysis of nuclear ma- terials must take into account the different and in many cases unknown isotopic abundances compared with those encountered in naturally occurring samples. Consequently most determinations must reflect isotopic rather than elemental determinations. Methods for the analysis of natural element impurities in non-irradiated fuels for fission products actinides in spent fuel and for actinide impurities in reprocessing solutions of Pu and U by ICP- MS have been reported (921C350).The requirement to monitor long-lived radionuclides in the environment is of considerable importance in ascertaining long term radia- tion effects on humans and the demand for such measure- ments has dramatically increased in the ‘post Chernobyl era’. Conventional ICP-MS is limited in its application in this area due to the effect of molecular interferences below m/z 80 and because of insufficient sensitivity to determine some radionuclides directly in environmental samples. To address this need a high-resolution ICP-MS system employ- ing an ultrasonic nebulizer has been applied to the measurement of long-lived radionuclides (9 1/3587). A ten- fold gain in sensitivity using the ultrasonic nebulizer was reported. At low concentrations more accurate isotopic information was obtained by employing the high-resolution instrument compared with a conventional quadrupole system by virtue of the improved counting statistics resulting from the greater efficiency of ion transmission in the high-resolution instrument.The ICP-MS method has also been applied to the analysis of radioactive wastes in ground waters surface waters and other forms of aqueous wastes (92/C3740). Developments in methodology for sample dissolution and chemical separation in addition to instrumental optimization for the analysis of both total uranium and its isotopes were described. The determina- tion of traces amounts of 237Np in enriched uranium solutions by ICP-MS has also been reported (921C34 19). In this procedure the 237Np was extracted by 0.5 mol dme3 thenoyltrifluoroacetone in xylene and re-extracted in 10 mol dm-3 HNO and finally diluting to 1 mol dmw3 HN03 prior to ICP-MS analysis.A commercial LA system has been modified for hot cell operation (921C7 10) and applied to the direct analysis of a number of radioactive materials using ICP-MS. Inductively coupled plasma AES continues to enjoy widespread use in the nuclear industry. However the complex nature of the spectra produced from such ma- terials means that in the majority of cases some form of extraction1separation is required prior to analysis. The separation of some REE from a uranium matrix by a two step liquid-liquid extraction procedure and analysis by ICP- AES has been described (92/17 17). The first stage involved the separation of the REE by complexing with tributyl phosphate in carbon tetrachloride.The second stage in- volved the use of tri-n-octylphosphine oxide for the removal of the residual traces of uranium from the aqueous phase. Recoveries of REE obtained using this method were in the range 90-103°/o while the LODs achieved by ICP- AES ranged between 0.2 and 9.5 ng ml-l. Reversed-phase partition chromatography has been employed for the pre- separation of the uranium matrix prior to analysis of trace elements by ICP-AES (92/4030). A paper detailing an ICP spectral atlas for uranium has been published (92/186). Optical emission spectra from high-purity normal abun- dance uranium were generated using a glovebox enclosed ICP. Spectra covering the range 197-700 nm were docu- mented and a general commentary on uranium ICP spectroscopy was presented. A number of abstracts have been received concerning the application of XRF in the nuclear industry.The determination of Fe and Ti in uranium by EDXRF was described (9213903). Combined gamma and passive XRF measurements have been employed for the measurement of 23sU enrichment and total U concentrations (92/3902). A review has been published detailing the present status of radionuclide determination in coals using XRF (9 114028). 2.5. Process Analysis and Automation The main emphasis in abstracts received relating to laboratory automation were concerned with automation of front-end sample introduction and sample preparation. An inexpensive automated system capable of multi-component standard preparation was described (9 1 /3670).This proto- type system was constructed from commercially available372R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL. 7 inert valves which were controlled from a PC. The system also performed automated sample spiking and could be used in conjunction with a laboratory robot. Similarly the analytical performance of an automated samplehtandard preparation system for AAS has been described (921C3701). An apparatus for automatically introducing organometallic samples to an ICP has been reported (9213 12 1 ). The liquid sample stream was continually injected into a heated stream of argon gas which was introduced continuously into the plasma. A fuIIy automated fusion system for rapid sample preparation of fused beads for XRF analysis has also been described (9213725).The system was capable of high-temperature borate-type or low-temperature peroxide fusions. An automated system for the dissolution of titanium oxide employing a microwave oven and a labora- tory robot has been reported. The system weighed out samples added acid carried out microwave digestion diluted the solutions transferred the solutions into breakers and cleaned the digestion vessels. The system was able to process 60 samples in 16.5 h (921600). A robotic system for the preparation of Ta powder for trace analysis was also reported (921225). 3. ADVANCED MATERIALS Developments made in analytical techniques and methodo- logy for the analysis of advanced materials are reviewed in this section of the Update.The key areas in which progress has been reported in the past year are highlighted in the text. A comprehensive summary of reported analytical methods of relevance to the characterization of advanced materials is provided in Table 3. 3.1. Polymers and Composites The materials encountered in the pIastics industry are enormously varied in terms of chemical composition. Base polymers which themselves can be extremely pure in respect of trace element content may be formulated with selected compounds from a vast range of additives (e.g. pigments fillers fibres and flame retardents) in order to achieve particular physical properties. The requirements for analysis range from highly accurate precise and rapid bulk quantification at the per centage level to spatially resolved lateral and depth profiling for trace constituents.Consequently no single analytical technique is likely to be suitable for all applications in this field. The diversity of the approaches which can be employed is evident from the literature. The major disadvantage of using ICP- or flame-based instrumentation for the analysis of plastics is the time required for sample preparation. Some materials containing polymers are soluble in aqueous solution (92/2207) but most sample preparation regimes rely on aggressive ap- proaches involving acid digestion and often employing oxidants such as hydrogen peroxide which can be used for the digestion of poly(viny1 chloride) (9212604 921C3653). Wet oxidation is the method of choice for the determina- tion of P as it prevents the losses of volatile species but conventional hot-plate acid digestion procedures can be relatively slow.This is particularly true for high-perform- ance polymers which have characteristics of high strength and modulus and are resistant to the effects of elevated temperature. A method for the determination of P (present as polyphosphoric acid) in poly(p-phenylenebenzobisoxya- zole) a rigid rod aromatic heterocyclic polymer was described in which microwave technology was used to speed up the digestion process (921C3355). The film was decomposed in H2S04 and HN03 and the resulting solution analysed by ICP-AES; and the method was validated using spiking and an independent standard. A spectral interfer- ence from sulfur (due to the acid) was identified at the 178.290 nm P line but this could be avoided by use of alternative wavelengths at 213.620 and 214.914 nm.The use of hot corrosive acids in sample preparation procedures often presents a safety hazard and for this reason automa- tion of such methods can be desirable. A system based on a labovatory robot has been developed for the determination of trace metals on the surface of epoxy laminates used in the manufacture of printed circuit boards (92/224). The method involved the immersion of the circuit board in a mixture of hot HN03 and HCl followed by detection of metals in the resulting solution by plasma AES. Some of the system hardware was modified to perform in a corrosive environment and it was reported that the potential for acid spillage and related accidents was much reduced.The system also provided a shorter analysis time for quality assurance testing. Polymers are now increasingly used in preconcentration methods and a number of papers on this topic have been published in the past year. These included the synthesis and use of chelating and polymeric resins such as phospho- ramidate for Ga and In (921409); tercopolymeric resins involving 8-hydroxyquinoline and resorcinol-hydroqui- none for Cd and Zn (921423); macroporous poly(viny1 amidine thiocyanate-thiourea) for Be Cr Cu La Ti V and Y (921 1693); poly(dithi0carbamate) for platinum group metals (921C3387); polyacrylonitrile for Co Mn and Ni (9211633); and polyurethane for Au Pd and Pt (92/58 921 1 66). Other abstracts concerning polymers which are indirectly associated with AS procedures included the investigation of blanks for S arising from synthetic tubing used in argon supply lines for ICP-AES (92/2625) and the use of PTFE slurry to prevent the formation of carbides in the determination of refractory elements by ETV-ICP-AES (91/3590). X-ray methods remain popular for direct analysis.Solid and relatively inexpensive energy dispersive XRF instru- ments are finding increasing application in quality control of engineering plastics (921C3714) and in screening of paints for Pb for example (91lC3733). Wavelength disper- sive instruments employing multi-layer crystals are increas- ingly being used to detect elements of low atomic number and analytical performance data have been published for the determination of F in fluoro-polymers (921 199).Total reflection XRF is now a well established branch of the technique and a review of applications including polymers has been published (9114037). An overview of the applica- tions of PIXE to quantitative trace element determination including an examination of polymer insulation for high- voltage cables may be of interest (9 113955). The characteri- zation of polyaniline thin films on stainless-steel and titanium alloy substrates has been carried out using low energy electron induced X-ray spectrometry XRF and GD- AES (921C667). The growth of the films via an electrodepo- sition route was monitored by examining the degree of incorporation of sulfate anions. Since polyanilines are conducting polymers this facilitated the application of GD- AES which was used for depth profiling.Surface analysis continues to be an important topic in the materials field and reviews on the application of SIMS (92/ 1305) electron- and ion-beam analysis (9211210) and RIMS (92/1578) have been published. The use of charge compensation in imaging of insulator materials by time-of-flight SIMS has been described (921956). The system was applied to the examination of PTFE-glass fibre and silicone-contami- nated polypropylene fibre electrical insulators. Lateral imaging and depth profiling SIMS studies have also been carried out on spatially modified polymers (92/24). ItJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL. 7 373R Table 3 SUMMARY OF ANALYSES OF ADVANCED MATERIALS Technique; atomization; analyte form* Element Matrix POLYMERS AND COMPOSITES- Sample treatmentlcomments Reference 9211855 921331 92lC365 3 9213 I50 9 1 I3964 9213205 9212207 921 I99 921 I83 92lC3 35 5 921 1855 91x3733 92123 1 92lC667 9213 150 9213 106 92lC3646 92lC3646 9211678 92lC3646 921 1678 9 llC3734 Ba Cd Cd C1 Cr Cr c u F N P Pb Pb S S S Sb Sb Si Ti Ti Zn Acrylate-styrene copolymers Leather X-ray absorption Preparation and characterization of metal diacrylate containing polymer for X-ray protection Samples were treated with sulfuric acid and H,O for the determination of Cd at levels of 2 ppm and above; recoveries were in the range 97- 100% with addition of H,O,; analysis using tungsten coil atomizer indirect determination at 338.29 nm Ag line with LOD of 5 ppm HN0,-H2S0 at 45 “C for 1 h and diluted with water and CaCI solution Dissolution of sample in 2 h using HN03-H2S0 Recovery of chloride by precipitation with Ag and Sample was ground digested in concentrated Review article with 31 ref.Dissolution of polymer complex in water and analysis using an air-C,H flame; no interference found from 400-fold excess of polymer for detection of Cu in range 0.5-3 ppm proportional counter and a multilayer AX06 crystal; detection in the range 120 ppm to per cent. levels Study of interaction between N-containing excited species in the plasma and surface interactions with polymer Microwave digestion using H,SO and HNO,; spectral interference from sulfur avoided by using 2 14.9 14 nm P line Measurement of Ka line for 30 s using a flow As for Ba Samples were ground to 200 mesh to remove homogeneity errors and analyte detected in the range 0.06-2.2% mlm by energy dispersive instrumentation employing a Io9Cd radioisotope source Wet digestion of sample in open vessel Measurement of sulfate incorporation in films and levels of dopant; correlation with GD-AES depth profiling Sample prepared using ammonia solution and calibrated using 1% vlv matrix matched standards; detection using 182.04 nm S line Dissolution of antimony-based finishing paint coating AA;F using slotted tube;L PVC AA;ETA;S Polymers AE;ICP;L Leather AA;F;L Leather Polymer metallo-complexes AAi-i- AA;F;L Fluoropolymers XRF;-;S Polypropylene AE or MS;corona disc ha rge;- Poly(p-phen ylene benzobisoxyazole) AE;ICP;L Acrylate-styrene copolymers Paint X-ray absorption XRF;-;S Wool Polyaniline thin films AE;plasma;L XRF;-;S Polymers AE; I CP; L Dried paint Rubber Si-containing polymers Dried paints Plastics Dried paints AA or AE;F or 1CP;L AE;spark;S AE;spark;S AA or AE;F or 1CP;L AE;spark;S AA or AE;F or 1CP;L XRF-;S Direct analysis using novel ‘sliding spark’ excitation Direct analysis using novel ‘sliding spark’ excitation Dissolution of dried paint sample source source Direct analysis using novel ‘sliding spark’ excitation As for Ti source Various (4) Paint on steel Measurement of paint thickness using Compton X-ray scatter from the painted steel sheet and intensity corrections for presence of C Fe Mo and Ti preferred to aqueous measurement dissolution in hot HCI and HNO using robotic protocol Study of adhesion of sputter cleaned polyimide to metal surfaces by detection of Cr Ti and Zr Dissolution of dried paint sample and detection of Cr Fe Ti and Zn Detection of Ba Cd P and Zn in organic media Quantitative measurement of trace metals by Various (4) Vinyl stabilisers Various Epoxy laminates AE;ICP;L AE;plasma;L 9212 I9 921224 Various (3) Metal-polyimide interfaces SIMS 9211414 92t 1676 Various (4) Dried paints AA or AE;F or 1CP;L374R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL.7 Table 3 SUMMARY OF ANALYSES OF ADVANCED MATERIALS-continued Technique; atomization; analyte form* AA or AE;F or 1CP;L AA;F;L Sample treatmentlcomments Analysis of dirt resistant paints for Cu Sn and Zn using a dissolution method Comparison of dissolution using H2S0,-H,O,-NH,OH-EDTA procedure and H,SO,-H,O,-HNO method Direct analysis of metals in polymers in the range 10 ppb-% mlm levels; precision values of 5% RSD reported Direct solid sampling for the detection of Cr Cu Co Fe Mn and Ni; water extraction for Na; comparative data from NAA and synchrotron radiation XRF fundamental parameter method used in estimation of concentration with single standard for up to five inorganic fillers Sample presented in disk or pellet form and Reference 9211679 9212604 921C3454 92lC354 1 921C37 14 9212 1 72 921388 1 921 1 326 9212353 9213063 92/C47 1 921 1 326 9211 337 921 1 340 9212296 9212353 921C3609 Element Matrix Various (3) Dry paint Various (4) PVC Various Polymers MS;LA and 1CP;S Various (7) Polycarbonate AA;ETA;S or L Various (5) Thermoplastic compounds XRF;-;S SEMICONDUCTORS- A1 Al As As As B B B B B B B Be Be C C C Ca cu Silicon substrates Germanium and silicon SIMS MS; ETA;S Study of re-distribution of ion implanted A1 Samples were evaporated electrothermally in vacuo and atoms were excited using laser radiation prior to detection by time of flight MS; LODs of 0.1-0.2 ppb were reported Study of effect on primary beam parameters were investigated to optimize detection in shallow junctions Quantitative depth profiling Silicon SIMS Molybdenum silicide- Silicon silicon layers SlMS AA;ETA;L Depth profiling by chemical etching; the use of Direct determination As for As Quantitative analysis for B in a silicide sample; error Quantitative detection of B impurity Study of matrix effects on accuracy of quantitaitve As for As platforms and chemical modifiers was studied correction in dopant profile analysis MS;spark;S SIMS SIMS SIMS SIMS Silicon Silicon Semiconductor Silicon dioxide-silicon layer Silicon Molybdenum silicide- silicon layers Silica and silicon SIMS AE;ETV-1CP;L Analyte was extracted with ethyl violet into toluene and vaporized at 1400 "C in a reducing hydrogen atmosphere to improve sensitivity LOD of 1 ppb reported Depth profiling of Be doped structures grown by molecular beam epitaxy Depth profiling of Be as dopant Novel discharge cell accommodating flat samples was used for determination of C at sub-ppm levels Detection of the SbC polyatomic ion was found to improve sensitivity 3-fold Use of load line calibration technique to achieve reproducibility of 4.5% in quantitative determinations Pre-volatilization used to remove gallium up to 0.3% mlv in an HNO medium to avoid interference on Ca; LOD of 0.057 ppm Ca reported Sample masses up to 20 mg analysed directly by ET volatilization into flame and response calibrated using aqueous standards; LOD of 0.1 ppb reported by mechanochemical polishing Quantitative analysis for Cu introduced into silicon Quantification of F levels on HF-treated surface Sample was diluted 7-20-fold with 2-ethoxyethyl acetate and introduced directly into ICP-MS system using oxygen gas to remove C deposition on cone; LOD was 1 ppb 921967 Galium arsenide layered structures Aluminium gallium arsenide Silicon wafers RIMS RIMS MS;GD;S 9211421 921C339 Indium antimonide SIMS 921975 Silicon SIMS 9212340 Gallium AA;ETA and ETA-F;L 921C769 High-purity germanium LE1;ET and F S and L 92lC5 86 c u Silicon SIMS and XPS 921 1278 F Silica-silicon substrates Fe Photoresist SlMS and XPS MS;lCP;L 921 1 244 9211 163JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL.7 375R Table 3 Element Fe Fe Fe Ga Ga H H In SUMMARY OF ANALYSES OF ADVANCED MATERIALS-continued Technique; atomization; analyte form* SIMS Matrix Indium phosphide Sample treatmentlcomments Spatial investigation of Fe concentrations in doped ingot Measurement of Fe contamination in non-uniform highly luminescent regions of sample on the micrometre scale Pre-treatment by ashing or dilution 7-10-fold with organic solvent; LOD of 0.2 ppb reported Films were dissolved in aqua regia evaporated and mixed with internal RMs As for As Methods of overcoming gaseous residual contaminants to achieve low LODs Quantitative analysis in good agreement with NAA method Sample masses up to 20 mg analysed directly by ET volatilization into flame and response calibrated using aqueous standards; LOD of 0.001 ppb reported Sputter coating of platform with sample addition of dilute HNO in situ and direct atomization in ETA; detection of In at a concentration of 600 PPm Sputtered neutral volatilization combined with resonance ionization MS used to eliminate isobaric interferences; LOD of 0.3 ppb reported Comparison of methods for determination of In- based compounds As for Ga Study of Li depth profile in sample aged over a six As for Fe As for Fe Non-destructive method for quantification of Ni; As for C Improved method for quantitative distribution of 0; year period accuracy confirmed by FAAS repeatability 2 4 % relative and accuracy of within 1Ooh reported Quantitative determination of 0 using the load line calibration method; reproducibility of I-2% reported Quantitative determination of intersitially dissolved oxygen with a repeatability of 3% relative As for B Indirect method based on formation of bismuth phosphomolybdate complex and extraction into IBMK; detection of Bi at 223.06 nm line Quantification of S in thin films Reference 921 1280 92/C 1449 9 2 x 3 5 38 921294 1 92/3063 92/ 1 608 92/280 1 92/C586 92/C778 9211 325 921 I8 10 921294 I 921966 9211 163 92lC3538 9212804 92/C339 92/23 16 9212344 9212796 92lC47 1 9212452 921994 9 113856 92lC 1449 921 1245 9 llC368 1 91lC3681 921334 9 2 x 5 3 2 92lC696 Indium phosphide SIMS Photoresist MS;ETV-ICP;L Gold films contacts AE;-;S Silicon Semiconductors AA; ETA; L SIMS Silicon-germanium alloys SIMS Cadmium mercury telluride LE1;ET and F;S and L In Cadmium telluride single crystals AA;ETA;S Silicon RIMS;-;S In In Semiconductors Gold film contacts Cadmium mercury telluride Photoresist Photoresist Silicon wafers XRF or AA or AE;FS or L AE;-;S SIMS In Li Na Na Ni MS;ICP;L MS;ETV-ICP;L XRF;-;S 0 0 Silicon wafers Czochralski-silicon MS;GD;S SIMS 0 Silicon SIMS 0 Czochralski-silicon SIMS P P Silicon High-purity silicon MS;spark;S AA;-;L S Si Cadmium telluride-cadmium sulfide films Semiconductors Electron probe MS;ICP;L Si was volatilized from acid dissolution mixture as tetrafluoride complexed to form molybdosilicic acid prior to indirect determination of Si as molybdenum As for Fe Study of doping of Sn in indium phosphide grown by Application of tungsten coil vaporization for molecular beam epitaxy introducing microlitre samples; detection down to 0.01 ppb for a I g sample As for Th Preconcentration of trace impurities by chelation with hexamethylene ammonium hexamethylene dithiocarbamate extraction chromatography platforms and Ni Mg and Pd nitrates as chemical modifiers to remove interference effects Separation of In from impurity elements by Layer by layer chemical etching of substrates; use of Si Sn Indium phosphide Indium phosphide SIMS SIMS MS;ICP; L Th Semiconductors U Various Semiconductors Silicon and germanium tetrachlorides MS; ICP; L AA;ETA;L Various Indium and indium phosphide Semiconductors AE;ICP;L Various ( 13) AA; ETA;L376R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL.7 Table 3 SUMMARY OF ANALYSES OF ADVANCED MATERIALS-continued Element Various ( 4 ) Various (4) Various (4) Various (3) Various (6) Various ( 3 ) Various ( 3 ) Various ( 3 ) Various (8) Various (6) Various (7) Various ( 4 ) Various ( 3 ) Matrix Microelectronic devices Aluminium gallium arsenide Indium phosphide Semiconductors Silicon wafers Silicon wafers Silicon Gallium phosphide Cadmium stannate-zinc sulfide substrates Silicon wafer Silica-silicon substrates Silicon wafers Amorphous silicon solar cell Various ( 1 1) Silicon nitride films on gallium arsenide Various ( 10) Bismuth germanate Various ( 5 ) Indium phosphide Various (4) Silicon wafers Various ( 14) Semiconductors Various ( 3 ) Gallium arsenide GLASSES- Al Silicate glasses B Borop hosphosilicate glass films Technique; atomization; analyte form* SIMS SIMS SIMS MS;GD;S SIMS XRF;-;S RIMS SIMS SIMS SIMS SIMS SIMS SIMS SIMS AE;-;- AA;ETA;L XRF;-;S MS;spark;S SIMS XRF;-;S XRF;-;S B Borophosphosilicate glass Electron microprobe B Borophosphosil icate glass XRF;-;S B Quartz MS;ICP;L Sample treatmentlcomments oxide and nitride layers and detect traces of CI and F from processing Caesium ion bombardment for quantitative detection of Al As and Ga and depth profiling of Zn dopant Quantitative analysis for C H N and 0 using caesium ion bombardment and negative secondary ion collection Detection of C N and 0 using gallium as a sample binder Impurities such as C CI F H N and 0 were encapsulated in the interface made by wafer bonding and detected by depth profiling Implanted Co Cr and Ni detected using instrument with total reflection geometry; accuracy checked by FAS A 30 keV gallium ion beam used to identify thin Detection of Al Be and Co as impurities Use of background subtraction method to improve detection limits for C N and 0 by an order of magnitude detection; depth profiles of Cd H Mn Na 0 S Sn and Zn were measured Quantitation of surface contamination of Al B Ca K Mg and Na as a function of wafer storage time A 5.5 keV molecular oxygen ion bombardment was used to examine behaviour of CI Co Cu K Na Ni and Ti at the material interface quantitatively Al Cr Cu and Fe as contaminants nitrogen used to overcome interference from hydrogen in detection of B C and N Caesium and oxygen primary ion beams used for the measurement of As C Ca Cr Fe H Mg Mn 0 S and Zn impurities preconcentrate Cd Co Cr Cu Ga In Mn Ni V and Zn present as impurities HNO heated and then dissolved in 5 mol dm- HNO,; trace amounts of Al Cd Cu Cr and Ni were detected Total reflection instrument used to detect Fe Ni and Zn following vapour phase decomposition of the surface; measurement of Cu problematic due to losses Detection of trace elements in Cd and Te and related compounds Quantitative determination of C H and 0 Caesium and oxygen ion beams were used in Time-of-flight instrument used to detect Gas spraying method using carbon dioxide or Autoclave decomposition of samples to Samples were treated with a mixture of HCl and Reference 92/97 1 921 1003 9211331 9211341 921 1 546 921 1999 9212028 9212 163 9212 9212 9212 70 77 81 9212331 9212332 9212 35 6 9212447 9212509 9212777 92/28 17 9213 174 Samples were prepared by r.f.sputtering and the 9213954 composition of the films produced were examined using a high resolution dual crystal wavelength dispersive instrument spectrometry with conventional wavelength dispersive measurement Study of lateral uniformity of composition and film thickness; quantitative analysis demonstrated Direct determination using wavelength dispersive instrument suppress volatilization of B during HF acid decomposition Comparison of low energy electron induced X-ray 9 2 x 4 7 9 921 1 749 921 1904 92lC3739 Investigation of use of mannitol and dulcitol toJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL.7 377R Table 3 SUMMARY OF ANALYSES OF ADVANCED MATERIALS-continued Element c o Fe Na P Pb Si Various Various Various (9) Various (60) Various Various (4) Various (7) Matrix Zirconium fluoride Zirconium fluoride Float glass Borophosphosilicate glass films Borosilicate and Glass mineral glasses Aluminium fluoride Fluorophosphate glasses Sheet glass fragments NIST SRM 6 10 Glass NIST Mineral Glass K-411 Lithium and aluminium Optical glass precursors fluorides CERAMICS AND REFRACTORIES- Technique; atomization; analyte form* AA;ETA;L AA;ETA;L Electron microprobe or AA;-;L XRF-$3 AA or AE;F or 1CP;L AE;ICP;L AEi-i- AE or MS; laser- ICP or 1CP;S or L XRF or AE; 1CP:S or L Ion microprobe Electron AA;ETA;S microprobe AA;F or ETA;L Sample treatmentlcomments Use of Zeeman-effect background correction and Pd(NO,) and HNO as chemical modifiers to overcome interference from fluoride; recovery 100- 105% achieved Use of Zeeman-effect background correction and Pd(NO,) and HNO as chemical modifiers to overcome interference from fluoride; recovery 97-105% achieved Distribution of sodium oxide in surface layers was investigated using an etching process Use of wavelength dispersive instrument for quantitative analysis using fused phosphorus standards; agreement obtained with independent ICP-AES data Sample was crushed melted and taken into solution and a variety of detection techniques compared Comparison of sodium tetraborate-sodium carbonate fusion method and decomposition with HF in a sealed vessel impurity elements at ppb level direct solid sampling using LA Technique described for the determination of Comparison of wet chemical ICP based methods and Comparison of techniques for identification and quantification of elements present for forensic purposes Investigation of the suitablity of the ion microprobe as a technique for standardless quantitative analysis Use of calculation method in improving quantitative electron microprobe analysis Slurry deposition onto pyrolytic platforms for determination of Cu Fe Ni and Pb at ppm levels Preconcentration of Ag Bi Co Cu Ni Pb and Zn impurities in metal fluorides by extraction of diethyldithiocarbamate complexes into iso- propanol; flame detection only used for Ag and Zn Al Aluminium oxide dusts AA;-;L Al Silicon carbide B Silicon dioxide AE;ICP;L AE;DCP;L C Superconductor SIMS Ca Silicon carbide AE;ICP;L c o Lanthanum and yttrium AA;ETA;S oxides Fe Silicon nitride AE; 1CP;S H Ni 0 Fusion with potassium pyrosulfate preferred to direct acid decomposition method - Decomposition of sample with HF-HNO in the presence of mannitol in a closed vessel and subsequent evaporation of silicon dioxide Minor isotope in situ ion implantation used to provide quantification in a sputtered thin film sample Cation exchange on AG 50W-X4 column to remove Na; then elution with 200 ml of 0.2 mol dm-3 HNO Coprecipitation with APDC from HNO solution; recoveries in range 100-103% and RSDs 1.9-3.0% for direct analysis of precipitate Sample (0.05-0.5 g) dispersed in 100 ml of 0.5Oh sodium hexa(metaph0sphate) solution as dispersant; this was agitated ultrasonically and the slurry aspirated into the ICP Measurement by detection of protonated metal ion; SIMS was used for near-surface detection and laser MS for bulk determination Coprecipitation with APDC from HNO solution; recoveries in range 95- I001 and RSDs 3.9-4.1 O/o for direct analysis of precipitate Superconductor SIMS or laser MS Lanthanum and yttrium AA; ETA;S oxides Superconductor SIMS As for C Reference 92/12 921 12 9211915 921300 I 921 1 84 92lC3625 9 113904 92IC590 921946 9211 253 921 1 748 9212206 9213065 921 I 763 9213044 92156 9212362 9213044 921272 1 92lC3 5 36 9212927 921212 1 9212362378R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL.7 Table 3 SUMMARY OF ANALYSES OF ADVANCED MATERIALS-continued Technique; atomization analyte form* AE:ICP or F L Element S Zr REE REE REE REE (14) REE (14) REE (14) REE REE ( 1 5) Various ( 10) Various (23) Various (2 1 ) Various (7) Various (20) Various (8) Various (5) Various (3) Various (4) Various ( 1 2) Matrix Superconductors Sample treatmenticomments Indirect determination by flame using precipitation as barium sulfate; matrix interference was removed by pre-separation using a strong acid cation- exchange column; ICP detection of S at 182.043 nm compatible with determination of N by titration quantitative analysis; LODs reported in the range 0.02-0.2 ppm in the solid 1 ppm reported layer pelleting technique and critical thickness studies; LODs in the range 20-100 ppm Orthogonal experimental design used to optimize conditions for detection of Ce Dy Er Eu Gd Ho La Lu Nd Pr Tb Tm Y and Yb Use of correction factors to compensate for interferences without the use of matrix matching of standards Optimization of parameters using orthogonal experimental design; LODs 5- 100 ppm Impurities were separated in 10 mim by HLPC using a silica-octadecyl column and gradient elution with 2-hydroxyisobutyric acid Fusion with 1 + 1 lithium borate-lithium tetraborate with iodine pentoxide added as a fusion agent; RSDs in the range 0.75-3.59% reported Lanthanum hydroxide was used to coprecipitate Co Cr Cu Fe Mn NI Ti V Zn and Zr to separate from the matrix graphite and 5% sodium fluoride and evaporated from crater of graphite anode columns; simultaneous recovery of elements after separation from matrix at pH 4 with 9 mol dm-3 HNO as eluant gave recoveries in the range 96- 102Oh by choice of background correction line selection and matrix matching methods; agreement reported with XRF method Reduction in blank levels by use of sealed double PTFE vessel for acid purification for the detection of Al Ca Cu Fe Mg Mn Na and Ti metaphosphate containing I OW lithium carbonate) for detection of Bi Ca Cu Pb and Sr Solution of tungsten oxide mixed with 1-(2- pyridylazo)-2-naphthol to precipitate Co Cu and Ni and were separated using ammonium chloride- ammonia solution pH 10 buffer Detection of Cr Mn Nb Ni and V qualitatively using XRF and quantitatively by ICP Powdered samples were mixed 1 + 1 with graphite powder and analysed for Al Co Cr Fe Mg Mn Mo Ni Pb Si Sn and V as impurities; LODs reported at ppm levels Sample shaken with solvent mixture of 5+ 1 gallium oxide-potassium chloride; for niobium oxide graphite powder also added detection of Ag Al Ca Fe Mg Mn Nb Si Sn and Ti at 3-300 ppm Ashing followed by fusion with borate-carbonate mixture and extracted with 1 + 1 HCI; LOD reported in range 1-93 ppb in the solid Comparsion of several acid digestion procedures Use of chemically prepared standards to achieve Sample is spiked before separation by HPLC; LOD of Use of small sample (400 mg) by means of double- Powdered samples mixed with 10% powdered Use of iminodiacetate chelating resins on mini- Acid dissolution for Al B Fe Mn Mo Si and Ti Determination of 15 REE and Al Ca Fe Pb and Si Fusion of sample with 19-fold excess of flux (lithium Reference 92/28 13 92lC3548 92/32 921C467 921 1 860 9211933 92127 16 9212739 9213045 9213943 9 113795 9 1/38 17 9113858 9113995 9 113938 92154 921151 921 165 92lC5 9 7 921 I299 9211357 921 192 1 Zirconium nitride Yttrium oxide A E; I CP; L SIMS High-purity yttrium oxide Rare earth oxides ( 1 5) Isotope dilution MS XRF;-:S Samarium oxide AE;-;S Yttrium oxide AE;ICP;L Dysprosium oxide Terbium oxide AE;d.c. arc;S AE;ICP;L Rare earth oxide mixtures XRF;-:S Molybdenum oxide A E; ICP; L Mangesium oxide ceramic AE;d.c.arc$ Silicon nitride and silicon carbide AE;ICP;L Ceramic electrodes Rare earth oxide mixtures AE;ICP;L AE;ICP;L High-purity silica AA or AE;F or 1CP;L XRF;-;S Superconductors Tungsten oxide AA F L Titanium dioxide Superconductors XRF or AE;ICP; AE;a.c.arc;S S or L Various ( 1 0) Tantalum and niobium AE;d.c. arc$ oxides Various (16) Graphite AE;ICP;LJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL. 7 379R Table 3 SUMMARY OF ANALYSES OF ADVANCED MATERIALS-continued Technique; atomization; analyte form* XRF;-;L Reference 921 I925 9212059 9212084 9212202 9212204 921222 I 9212222 9212507 9212624 9212976 9212989 92lC3386 92x355 1 92lC3 5 5 8 Element Various (4) Various (1 6) Various (3) Various (7) Various (4) Various ( 1 1) Various (8) Various Various (8) Various (4) Various (4) Various ( 1 7) Various ( 1 0) Various (6) Matrix Superconductors Sample treatmentlcomments Microdroplet analysis combined with fundamental parameter method for standardless determination of Ba Ca Cu and TI as oxides Sample heated in platinum crucible with HF and H,SO and evaporated; residue heated with HF and H,PO until fluid became transparent Radionuclide source used to achieve detection of Ba Cu and Y with precision 3% or better; accuracy confirmed by ICP-AES Samples fused 1 + 19 with lithium metaphosphate at 850 "C for 50 min in a CO-C02 atmosphere; detection of Ba Bi Ca Cu Sr T1 and Y using a LiF(200) crystal Samples dissolved in dilute HCI or HNO and Ba Cu La and Y determined using Mn as internal standard Sodium chloride was used as carrier and indium as the internal standard; LODs in the range 1-5 ppm for B Bi Co Cr Mn Ni Pb Sb Sn V and Zn LODs for Ca Dy Er Ho La Tb Tm and Yb in the range 0.48-5.9 ppm; spike recoveries of 90-1 10%; RSDs <4% Comparison of sample preparation and direct insertion techniques Direct determination of Co Cr Cu Fe Mn Ni Pb and Zn reported; LODs in the range 0.07-0.3 ppm by FAAS Slurry nebulization of powdered sample for detection of Al Ca Fe and Mg; reported atomization efficiencies of 77- 1 OOYo for these elements Sample was dissolved in HNO and interference free lines were selected for the determination of Ce Nd Pr and Sm at ng ml-I levels digestion decomposition with ammonium sulfate and fusion with lithium tetraborate Sample dissolved in HF and HNO,; dissolved Si and remaining HF were removed by fuming with Use of dervative spectrometry to overcome spectral interferences in the determination of Al Ce Cu La Sm and Pb Comparison of three methods involving acid H2SO4 High-purity alumina A E ; I CP; L Superconductor films XRF;-;S Superconductors XRF;-;S Superconductors AE;ICP;L Terbium oxide AE;d.c.arc$ Yttrium oxide AR;ICP;L High-purity alumina Europium oxide AE;ICP;S or L AA;F and ETA;L Silicon nitride A E; I C P ; S Lanthanum oxide AE;ICP;L Lead zirconate-titanate ceramics AE;ICP;L Molybdenum disilicide AE;ICP;L Yttrium oxide AE;ICP;L CATALYSTS- Ir Pd Pt Pt Pt Pt Rh Rh Various ( 6 ) Catalysts and alumina Extraction with potassium xanthate by heating in a Dissolution of 0.2 g of sample in up to 10 ml of water bath for 25 min various acids or alternatively bomb digestion with HCl and H,O Sample mixued with conductive host matrix material; internal standardization employed to compensate for sputtering rate differences between samples Comparison with UV-visible spectrometry AES and AAS methods High-pressure decomposition (Knapp 1984); interferences due to Al Ca Fe P Pb S Si and Sn studied dithiocarbamate in the pH range 5.2-6.2; no inteference was found from 12 other elements Solvent extraction with potassium u-butyl As for Pt 921 1429 9214057 AE;ICP;L AA;FL Aluminium-based catalyst 9219 Alumina-based automotive catalysts AA;G D;S Catalysts 9212074 9212 12 1 XRF;-;S AA;ETA;L AE;ICP;L Catalysts Catalysts 9213047 Alumina-based automotive Catalysts catalysts AA;GD;S AE;ICP;L 9219 921286 Extraction with potassium hexyl xanthate by heating in a water bath for 15 min; RSD of t2% reported for 10 runs Fusion with lithium metaborate-tetraborate flux; good agreement obtained in round robin tests Zeolite-based fluid cracking catalysts XRF;-;S 9 l/C3657380R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL.7 Table 3 SUMMARY OF ANALYSES OF ADVANCED MATERIALS-continued Element Various (5) Various (3) Various (3) Various (3) Various (8) Technique; atomization; Matrix analyte form* Automotive catalysts XRF or MS;ICP;L Alumina-based catalysts XRF;-:S Zeolites XRF-;S Reforming catalyst XRF-;S Alumina-silica base catalysts AA;F;L Sample treatmentlcomments Reference 9214 1 5 Comparison of microwave digestion procedures and ICP-MS detection with wavelength dispersive XRF method for Ba Cd Fe Ni and Pd Comparison of XRF method with established procedures based on UV-visible spectrometry ETAAS and ICP-AES for CI Pt and Re Fusion of 1 g of calcined sample with 1.6 g of lithium borate 4.8 g of lithium tetraborate and 0.1 g of potassium iodide; detection of Al Na and Si Wavelength dispersive instrument used to achieve reproducibility of 1 O/o or better for determination of Ir Pt and Re of HNO nitric and fluoroboric acids 921425 9212418 9213077 Microwave oven slurry preparation using a mixture 92lC3655 * Hy indicates hydride generation and S L G and SI signify solid liquid gaseous and slurry sample introduction respectively.Other abbreviations are listed elsewhere. was reported that surface derivatized polymers metal doped conductive polymer films and patterned polymeric materials or fibres were mapped in two or three dimensions.The adhesion of metals such as Cr Ti and Zr to sputter- cleaned polyimide has also been investigated using SIMS (92/ 14 14). The application of LA to the analysis of polymeric materials was reported in two papers at the 1992 Plasma Winter Conference. Lord and Nelson (92/C3454) decribed the determination of trace elements in polymers by ICP-MS using single spot multiple spot and raster LA. It was reported that elements could be detected quantitatively in the range 10 ppb to per centage levels using a combination of pulse and analogue counting detector modes and that under optimum conditions RSDs of 5% could be achieved. The application of laser-induced AES for industrial on-line analysis has been described (92/C335 1).A high-power laser was used to ablate and excite the constituents of rubber slabs made during the early stages of tyre production. The emitted light was collected using an optical fibre connected to a spectrometer equipped with a multichannel analyser with high time resolution. The focused laser beam could be scanned across the the plane surface of the slabs to monitor spatial element distributions of compound constituents. A new technique known as sliding spark excitation has been described which allows the direct examination of non- conducting polymers by AES (92/C3646). The system allowed the generation of AE on the surface of the solid material although the abstract gives no details of how this was achieved. The excitation source was coupled via optical fibres to a spectrometer. Examples of applications cited included silicon-containing polymers antimony-containing rubbers or plastics incorporating different concentrations of titanium dioxide.3.2. Semiconductor Materials Over 150 abstracts were received in the year under review concerned with surface analysis techniques (primarily SIMS) for the characterization of semiconductor materials. Most of these abstracts are associated with SIMS 7 and the proceedings of this international conference on SIMS has now been published (e.g. see 92/2862). However only a small proportion of these papers was concerned with quantitative analysis. Where sufficient detail has been given in the abstract an entry has been made in the relevant section of Table 3. A few of the more pertinent papers are highlighted in the following section.One of the main difficulties encountered in the examina- tion of solids with a heterogeneous structure involves the calibration of instrument response. This is problematic because of the lack of availability of suitable reference standards. Since many of the materials under investigation have novel structures it is unlikely that external calibra- tion methods for surface analysis techniques such as SIMS will provide a complete solution to this problem. The use of relative sensitivity factors (RSFs) in SIMS for analytes in a particular matrix has been the subject of much investiga- tion. In one paper the RSFs for up to 74 elements implanted into 23 materials were studied over an 8 year period (9211020).It was found that the reproducibility of the RSFs was around 60% using several Cameca magnetic sector instruments with particular reference to silicon gallium arsenide and cadmium mercury telluride matrices. Plots of log RSF versus ionization potential of the sput- tered impurity elements were observed to have linear trends. The trends were similar for a variety of materials including semiconductors metals and insulators. The same workers observed similar trends in a more detailed study of silicon and silica (92/ 10 19). Relative sensitivity factors for 43 elements in silicon were measured using a Cameca IMS-3F system (9212298). Both caesium and oxygen ion bombardment were employed and secondary ions of the opposite polarity were detected. The influence of factors such as sample holder design (e.g.flatness or mask window type crater position) and spectrometer parameters (e.g. energy bandpass peak shape) on the reproducibility of RSFs in SIMS has been studied (92/2862). It was found that there is a relatively large spread in RSF values for repeat measurements of a single reference sample which would give rise to a commensurate uncertainty in the estimation of concentration. A number of SIMS round robin exercises have been conducted to aid in the process of making RSF values transferable between instruments and establish the accu- racy of quantitative methods (92/3223). The analysis of NIST prepared calibration standards for silicon and silica was carried out by five magnetic sector SIMS instruments and two quadrupole systems in seven laboratories (92/2861).The samples were implanted with Al C Cr Cu Fe and Na. Data on implanted high dose Cr Cu and Fe were also reported using Rutherford backscattering andJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL. 7 381R NAA. A Japanese round robin on the analysis of gallium arsenide was conducted in collaboration with 16 SIMS participants and 1 8 chemical analysis laboratories (92/22 18). The purpose of the trial was to obtain validated gallium arsenide standard materials for SIMS analysis and as a by-product acquire secondary-ion yield data. The statistics produced by the study were discussed in detail. Gallium arsenide was also the subject of two other SIMS round-robin trials (92/2338). Interlaboratory differences in the quantitative data were reduced to around 10% by the use of common calibration standards.The alternative approach recommended for quantitative analysis was that instrument dependent databases could be used to achieve an accuracy of approximately 50%. Several reviews have been published on the application of SIMS to the anal-vsis of semiconductor materials. These include the application of SIMS to the mapping of dopant distribution in silicon (92/1067 92/2803) and to quantita- tive depth profiling (92/ 1056. 92/2339). Sputtered neutral MS is increasingly finding a role in the characterization of bulk silicides and thin films (921963 9211069). This technique relies as the name implies on the detection of neutral species sputtered from the sample but the sampling process can be used in conjunction with RIMS.Systems of this type have been decribed for the determination of Fe and 0 s in silicon (92/1567) Mg in silicon (92/2315) and depth profiling of silica-indium phosphide materials (92/ 1325). Finally reviews comparing surface analysis and other techniques for the characterization of semiconductors may also be of interest (9211051 92/1058 92/1066 921 1068). Owing to the sensitivity requirements for the analysis of semiconductors techniques based on mass spectrometry tend to dominate the literature. Solids can be directly sampled using laser ablation and this procedure has been adopted in an investigation of dopant lateral diffusion in cobalt and tantalum silicides (92/1574). It was claimed that the LAMMA system used could achieve 1-3 pm resolution which was adequate for studying device lines in these materials.The LAMMA technique was used for the analysis of inorganic solutions by deposition on the porous layers of the surface of a silicon wafer anodically oxidized in HF (92/2821). It was indicated that this procedure resulted in preconcentration of impurities which were completely absorbed. The use of an ETV device for sample volatiliza- tion prior to laser ionization MS was described (92/388 1). Using this approach the sample was evaporated by means of a graphite ETA operated at 1700 "C in vacuo. The system was applied to the determination of A1 in germanium and silicon. Detection limits for A1 were reported to be 0.1 and 2 ng g-' respectively in these matrices. Spark source MS has found application in the the analysis of cadmium mercury telluride (92/2 19 1 92/28 17) and in the detection of P and B in silicon and semiquantitative analysis of gallium arsenide (92/C47 1).Glow discharge MS would appear to offer many of the advantages of spark source MS (92/ 134 I) including providing the depth profiling capability of the surface analysis techniques referred to above and two articles providing an overview of the technique have been pub- lished (921988 9211267). The main development in this field reported this year involved the construction of a new discharge cell that can accommodate flat samples (92/C399 92K3610). The geometry of the cell allowed the direct analysis of silicon wafers. It was reported that C and 0 could be detected at sub-ppm levels using a magnetic sector mass spectrometer.The relative merits of GDMS SIMS NAA and ICP-MS have been assessed for the analysis of refractory metals and their silicides used in low resistivity gates interconnections and ohmic contacts in minimum integrated circuit geomet- ries (92K3404). It was concluded that ICP-MS was the most suited to this application exceeding the sensitivity of the other techniques for the bulk characterization qf refractory metals. Certainly it would appear that ICP-MS is increasingly being employed in this field. Extremely high sensitivity can be achieved by the use of ETV sample introduction for ICP-MS. A system of this type has been applied to the determination of impurities in photoresist for very large scale integrated circuits (92K3538). It was found that a very small amount of sample could be used which resulted in less contamination of the spectrometer.The photoresist was diluted 10-fold with ethoxy ethyl acetate and an aliquot injected into the graphite tube. A decrease in spectral interferences from C and 0 polyatom- ics was observed in comparison with conventional nebuli- zation. Detection limits for Fe and Na in photoresist were 0.2 and 0.06 ppb respectively. The ETV-ICP-MS technique has also been used for the determination of Th and U in electronic materials (9 1/C368 1). Alpha particle emissions from these elements present at ppb levels can result in errors in the devices. Samples were prepared chemically in small volumes and a 10 pl aliquot was deposited to dry on a tungsten coil rod.The analytes were vaporized into the ICP-MS system and it was found to be possible to determine down to 0.01 ppb using this approach. The detection of Fe down to about 0.02 ppb has also been achieved using ETV-ICP-MS (92K3595). However per- haps the most effective method for improving sensitivity and/or reducing spectral interferences is to use a high- resolution MS detection system (92K3622). The determi- nation of P and S in aqueous and organic solutions has been demonstrated using such an instrument. Perhaps as a consequence of the success of ICP-MS in this field there were relatively few novel developments in the application of ICP-AES to the analysis of electronic materials. Those methods which have appeared are sum- marized in Table 3.However AAS would still appear to have something new to offer in this field. A new method of solid sampling has been described based on argon sputter- ing the sample and forming a layer on a graphite platform which is then placed in the graphite furnace of an atomic absorption spectrometer (92K778). It was found that for different materials the sputtered layer gave different responses on atomization. However if 20 pl of HN03 were deposited on top of the platform the sample appeared to be taken into solution and this removed the matrix effects thus allowing the use of aqueous calibration. Measurements indicated that when cadmium telluride ( 1 1 ) single crystals were used as the sputter target a film was formed with a stoichiometry of Te:Cd of 1.09:l on the platform.The method was applied to the determination of the impurities such as In present at a concentration of 600 ppm in cadmium telluride. A study has been made of the volatiliza- tion of Ca in a gallium matrix using ETAAS molecular absorption spectrometry and ETA-FAAS (92K769). It was found that gallium was evaporated at 900-1 100 "C when applied at the 10 ng level corresponding to the evolution of gallium oxide elucidated by MS studies. However when gallium was present as the matrix element at 10 pg the major fraction was found to vaporize as metal between 1120-2300 "C. Since Ca at the 1 ng level vaporizes above 1520 "C the use of a pre-volatilization temperature step to remove the matrix was found to allow the interference free determination of Ca up to a gallium concentration of 0.3% m/v in a nitric acid medium. A detection limit of 0.057 ppm was reported for the determination of Ca in gallium.Conventional X-ray jluorescence spectrometry does not offer the sensitivity required for the detection of trace dopants in semiconductor materials. However the tech- nique can be applied to the characterization of major components in films and to thickness measurement and progress in this area has been the subject of a review382R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL. 7 (92/222). The development of total reflection XRF has revitalized the use of the technique and a number of methods for the analysis of silicon wafers have now been published. These include the detection of Cu Fe Ni and Zn as impurities (92/2777 92/3274) and the measurement of ion-implanted Cr Co and Ni.In both cases the sample was dissolved using HF and silicon was volatilized as the fluoride prior to determination of analyte concentrations in solution by TXRF. Further improvements in sensitivity were claimed for a more advanced TXRF system which utilized monochromatic source radiation (92/3274 92/3905). The conventional X-ray tube was removed from the instrument and replaced with a rotating anode and a monochromator was added to improve the S/B ratio. An improvement factor of 1-2 orders of magnitude in terms of detection limit was reported. The application of the system to the determination of impurities on silicon wafers was described. The analysis of gallium arsenide by TXRF using two different commercial instruments has also been de- scribed (9211 895). 3.3.Glasses Ceramics and Refractories 3.3.1. Glasses There were fewer abstracts received in the year under review pertaining to the analysis ~f gfasses and related materials. A summary of analytical methods is provided in the relevant section of Table 3. Some methods for the analysis of glasses by ICP-AES involve dissolution with acid mixtures including HF. It is known that analytes can be lost as volatile fluorides using such procedures and the range of applications is therefore limited. However there is some evidence to suggest that if the decomposition is carried out in a sealed vessel Si may be retained (92/C3625). A microwave digestion procedure of this type was evaluated for the determination of Si in NIST SRMs by ICP-AES.It was reported that the method was found to be faster and as accurate as procedures based on fusion with sodium tetraborate-sodium carbonate. The determination of B in high-purity quartz may also be subject to error if an HF dissolution is employed (92K3739). It was found that the addition of mannitol or dulcitol in 1000-fold molar excess provided a means of achieving 100% recovery for B in an HF dissolution. However these organic compounds were found to reduce the ICP-MS signals for B as a result of carbon deposition on the sampling cone. This effect was overcome by the use of beryllium as an internal standard. The application of LA-ICP-AES and ICP-MS to the direct analysis of fluorophosphate glasses has been dis- cussed but no details were given in the abstract (921C590).An r.J planar magnetron GD source has been employed for the direct determination of elements in glass samples by AES (92K3647). The dependence of the analytical atomic and ionic line emission intensities on argon pressure (0.5-20 Pa) and r.f. power (50-200 W) was studied. A comparison has been made between the use of ICP- AES XRF and refractive index for the forensic characteri- zation of sheet glassfragments (92/946). The concentrations of nine elements were determined by ICP-AES and preci- sions in the range 1-10% were obtained. The X-ray intensities of five elements were determined by EDXRF and precisions in the range 1-25% were reported. It was concluded that the ICP-AES method while slower and destructive provided quantitative data which allowed improved discrimination with respect to the source of the material.However XRF methods are attractive in this type of application because they are non-destructive. Matrix interferences can be compensated for by use of correction factors based on mass absorption coefficients (91/3797). Limitations in terms of range of analyte coverage are being overcome as a result of recent developments in instrumen- tation which permit the detection of light elements such as B (92/1904). A method has been described for the determi- nation of P in borophosphosilicate and phosphosilicate glasses using WDXRF (9213001). The glasses were coated on a silicon wafer. Secondary spectral line intensities from the wafer were monitored and compared with those from an uncoated wafer and a fused P standard.The results were converted into P content and film thickness by relating the spectral line intensities for P and silicon. Good correlation was achieved with independent ICP-AES analysis of the glass films for P. In another study low energy electron loss induced X-ray spectrometry (LEEIXS) was applied to the quantitative determination of B in borophosphosilicate glass films (92K479). The instrumentation used was a WDXRF system equipped with a high-performance gas discharge tube as an electron source. Layered synthetic microstructures were used for dispersion which improved sensitivity for light elements. Unfortunately the abstract does not provide any information about the detection limit of the method. The application of ion microprobe analysis to the detec- tion of over 60 elements in NBS (now NIST) Glass SRM 610 has been described (92/1253).The variation of ion yield with atomic number was found to give a relatively smooth pattern which might allow a move towards stan- dardless analysis using the technique. However it was noted that Si which was a candidate element for normaliza- tion was most susceptible to variations in analytical conditions. The electron microprobe was applied to the measurement of elemental constituents in NIST SRM K411 Mineral Glass again for the purposes of calibration of response (92/1748). However it was noted that the study emphasized methodology and concept rather than the pursuit of numerical precision! The electron microprobe was also utilized in the non-destructive characterization of borophosphosilicate glass coatings (92/ 1 749).An accuracy of about 3.6% was achieved for the determination of B in glass films. It was considered that the electron microprobe method could be employed as a reference method to support production control methods based on XRF. 3.3.2. Ceramics refractories and catalysts The analysis of REE oxides continues be a focus for research effort. Secondary-ion MS has been used to deter- mine the concentration of REE in yttrium oxide (92/32). A Cameca IMS-3F system with a duoplasmatron primary-ion source was employed. Charring effects at the sample surface were eliminated by mixing the sample with graphite powder. Spectral interferences from polyatomic ions were suppressed using an energy filtering technique.The levels of REE were quantified using a calibration graph derived from chemically prepared synthetic standards. It was reported that detection limits were obtained in the range 0.02-0.2 ppm using this technique. Spectral inte!fevences are also a significant problem when ICP-AES is used to determine trace elements in yttrium oxide (92K3558). Intense yttrium lines were found to be adjacent to the lines for Ce I1 at 4 18.660 nm La I1 at 379.083 nm and Sm I1 at 359.262 nm. The determination of these elements was further compli- cated by sloped or curved background interferences. Spec- tral line overlaps were also observed in the analysis of Al Cu and Pb in this matrix. A numerical derivative technique was applied to correct for such spectral interferences.It was reported that all background-related interferences were eliminated using this approach and that the analytical lines for Al Cu and Pb were resolved from the interfering lines. As a result of the enhanced spectral resolution achieved using the derivative procedure detection limits were improved by 7- 1 10-fold. A high-resolution sequential spectrometer has been applied to the determination of traceJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL. 7 383R elements in REE mixtures (92lC3808). The system incor- porated an automatic exit and entrance slit mechanism that permitted the optimization of resolution sample through- put and detection for seqential measurement which related to the spectral complexity around the analyte line.It is possible to eliminate spectral interferences by using a separation procedure prior to analysis. The determination of REE in terbium and terbium oxide has been carried out using an interfaced HPLC-ICP-AES system (9213045). The rare earth impurities were separated from the sample matrix by gradient elution from a silica-octadecyl column with 2-hydroxyisobutyric acid. The mutual separation of impurities could be carried out satisfactorily within 10 min. The rapid elution resulted in sharp peaks and sensitive detection. Up to 30 pl of a 1% m/v solution of terbium could be injected onto the column. The use of a power setting of 800 W was found to give a 5-fold improvement in SIB compared with operation at the usual setting of 1300 W. Recoveries of REE from the terbium oxide matrix were in the range 85- 100% and it was found unnecessary to use matrix matched calibration standards. The characterization of catalysts remains a major chal- lenge in the field of trace inorganic analysis.Fluid cracking catalysts are intensively used in the petroleum industry. These catalysts are supported on zeolites (crystalline or amorphous silica-alumina structures) which can be impreg- nated with REE to alter their functionality. The determina- tion of the si1ica:alumina ratio is an important parameter in the characterization of zeolites and several methods have been published in the last year based on SIMS (92/1605) PIXE XRF and NAA (91/4013) and fusion followed by XRF (92/2478). The detection of poisons such as Ni and V which derive from the processing of petroleum oils is extremely important and highly sensitive methods are required.Fusion-based XRF procedures (9 1/C3657 92/C595) have a role to play in such applications but rapid dissolution methods based on microwave slurry sample preparation for FAAS or ICP-AES may provide a viable alternative (92K3655). However since catalysts tend to be contaminated on the surface of the support SIMS can be used advantageously and two overview articles on the application of the technique to the characterization of petroleum cracking catal-vsts may be of interest (92/ 1490). Precious meta/ catalysts supported on alumina are widely used in the petrochemical industry as the means of altering hydrocarbon structures. Such ‘reforming’ catalysts tend to be based on the use of platinum although other elements such as iridium (92/1429) and palladium (92/4057) can be used in specific applications. In the year under review a number of methods have been published for the determina- tion of Pt in catalysts based on XRF (92/2074 92/3077) ICP-AES (92/286,92/3047) and ETAAS (92/2 12 1).Perhaps the most interesting application described involved the determination of C1 Pt and Re on alumina-based bimetallic reforming catalysts by XRF (921425). Chlorine is not an element which is easily determined by most atomic spectro- metry methods and a UV/VIS spectrometry procedure was adopted as a comparative method to assess accuracy. The XRF method developed was also compared with reference methods involving ICP-AES ETAAS and ED-SEM.Statis- tical evaluation of the data indicated that the proposed XRF method gave no significant bias. Automotive catalysts also make use of the properties of platinum group metals on alumina substrates. Two rapid microwave digestion procedures were described in which dissolution of such catalysts could be achieved in 2-3 h (921415). In the first the dried sample was digested in a mixture of HCI and HF acids in a microwave perfluro- alkoxy (PFA)-PTFE sealed vessel followed by treatment with HClO and aqua regia in an evaporating dish on a hot- plate. In the second method a mixture of HF HN03 and HCl was used in an initial microwave digestion step. The sample was cooled and neutralized with H3B03 the vessel was recapped and heated further in the microwave oven. In both cases the final solutions were diluted and analysed by ICP-MS.It was noted that the ICP-MS method compared favourably with existing ashing methods in terms of speed and WDXRF. In a relatively novel approach the determi- nation of Pt and Rh in automotive catalysts was carried out by GDAAS (92/9). The alumina-based catalyst was mixed with a conducting host matrix material and analysed directly thus avoiding time-consuming sample preparation steps. It was found that differences in sputtering efficiencies between samples could be compensated for by use of an internal standard. It was reported that the technique provided accurate results with relative errors of 2-3%. Relatively few papers have been published in compari- son with previous years on the analysis of alumina or other oxide-based ceramic materials.Work has continued on solid sampling methods for the ICP including the introduc- tion of ceramic powder in the form of a slurry (92/2494) by ETV (92/280) and by direct sample insertion (92/280 9212507). Chemical methods for sample preparation have also been described (92/ 1763 92/2059). The analysis of perovskite ceramics has received some attention in the year under review. Acid dissolution and fusion-based sample preparation procedures have been developed for the analy- sis of lead zirconate-titanate (92/C3385 92/C3386) and manganite and cobaltite perovskite electroceramics (92/2285) by ICP-AES. The application of GDAES to these materials was also discussed (92lC648). Samples were pressed and analysed following 1 0-fold dilution in a copper conducting host matrix.Analytical performance was as- sessed by comparison with an ICP-AES method. Lan- thanum and strontium manganite and cobaltite perovskite ceramics have also been characterized in the solid phase by LA-ICP-AES and ICP-MS (921C3374). A Q-switched ruby laser with an output energy of 0.1 J was employed for ICP- AES studies. Lanthanum was used as the internal standard. In the case of ICP-MS the samples were prepared as pressed pellets and ablated using a Nd:YAG laser with an output energy of 0.1-0.3 J. Strontium was used as an internal standard and calibration was achieved using external solid standards. Results obtained with the two methods were compared with ICP-AES analyses using a dissolution procedure.Papers continue to be published concerning the charac- terization of high-temperature superconductors. The great majority of these were concerned with the analysis of Y-Ba-Cu-0 type ceramics. Most of the wet chemical sample preparation methods reported for ICP-AES and AAS determinations were similar to those already in the literature. However in a novel approach AAS has been used as an in situ diagnostic tool to study the sputtering of high-temperature superconductors (92/3206). Hollow cath- ode lamps were employed as oxide targets using a Kaufman ion gun. The ground state Ba and Cu atoms ejected from the composite target during argon and oxygen-ion bombard- ment were studied as a function of sputtering parameters. The composition of high-temperature superconducting films and single crystals has been examined by ETAAS (92/2201).The central portion of the graphite furnace was lined with tantalum foil which was found to improve the sensitivity stability and reproducibility of the analytical method. It was reported that small amounts of sample (0.00 1-0.000 1 g) could be analysed using this procedure. X-ray .fluorescence remains a popular technique for the analysis of high-temperature superconductors using various types of instrumentation. X-ray excitation using a radionu- clide source (92/2084) a tungsten target tube (92/2202) and a synchrotron (92/3008) have a\\ been evaluated in this type of determination. In the last case a total reflection geometry384R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL.7 was adopted to minimize background radiation from the film substrate. A fundamental parameter XRF method was applied to the characterization of a TI-Ba-Ca-Cu-0 superconductor to avoid the need for standards containing TI which is poisonous (9211 925). It might be expected that LA-MS techniques may offer some utility in the characterization of superconductors. However the study of laser-sample interactions appears to be dominating this field at present (92/1246 92/1417 92/153 1 92/3258). This is because LA may provide a route to the preparation of high-quality superconducting thin films (92/1576 92/2 148,92/3 153). The application of SIMS to the analysis of these materials has received further attention. Quantitative methods for the determination of C and 0 (9212362) and H (92/2927) in Y-Ba-Cu-0 type superconductors have been published.Relative sensitivity factors for SIMS (92/ 1053) and Auger electron spectroscopy (92/1055) have also been determined in this matrix. Image depth profiling studies using SIMS have also been carried out (92/974 92/2 187). Finally a number of papers have been published or pre- sented on the analysis of non-oxide ceramics. As with other developing fields of materials science the application of SIMS is well represented. The coating of Nicalon fibres with silicon carbide has been studied by SIMS (92/ 152 1). It was found that there was no change in the fibre structure as a result of the coating process indicating that the fibre should retain its properties. A SIMS depth profiling technique has been used to examine fibre-matrix interfaces in silicon carbide fibre reinforced composites (92/15 1 1).The use of a conductive metal coating and electron bombardment during sputtering compensated for sample charging allowing the analysis of insulating ceramic materials. Lateral resolution of ion images was reported to be about 1 pm but depth resolution was claimed to be as low as 5-10 nm. The use of electron bombardment and self-compensation for reduction of surface charging of samples has also been applied to the characterization of silicon nitride (92/968) and oxide nitride and organic thin films (92/2873). A Cameca IMS-3F SIMS instrument utilizing a 200 nA 14.5 kV oxygen primary beam has been used to monitor B diffusion in silicon carbide films formed by chemical vapour deposition (92/2 189).The detection of positive ions allowed quantitative digital imaging for B. A SIMS method for the detection of N Ti and Si in the interface between silicon nitride and titanium metal was described (92/1161). The specific ions of titanium silicide and titanium nitride were selected for measurement. It was found that the method produced data which were in good agreement with XPS and Auger studies of the metal- ceramic interface. The application of SIMS to the quantita- tive analysis of titanium boride and titanium carbide wear protection coatings has also been reported (92/2868). It was commented that the signals from the metalloid species could be used to measure the extent of wear and to help explain wear resistance (e.g. as a result of oxidation).Ceramic materials are increasingly produced in fine powders and this provides opportunities for direct analysis by ICP-AES using the slurry procedure (921276). This approach has been adopted for the determination of Al Ca Fe and Mg in silicon nitride powder (92/2976) and for the determination of Fe in silicon nitride (92/C3536). In the latter case the sample (0.05-0.5 g) was diluted to 100 ml by the addition of 0.5% m/v aqueous sodium hexametaphos- phate (Graham's salt) as dispersant and slurried by ultra- sonic agitation. The sample was introduced directly into the ICP and the suspension was maintained by magnetic stirring. When samples have to be ground or pulverized prior to slurry preparation or to help speed up sample dissolution there is always the possibility of contamination by the equipment used.This has been the subject of study in the development of a method for the determination of impurities in sintered silicon carbide (92K3535). It was found that the use of a vibrating mill with pots made of iron tungsten carbide and zirconia caused contamination of the sample. In the case of zirconia this was found to be as much as 5% with 30 min of pulverization. Attempts were made to remove iron contamination by extraction with hydrochloric acid but this was found to extract other impurities from the sample. It was found that the best method to minimize the problem involved the dissolution of a small amount of sample (0.15 g) in an HF-HN03-H2S04 mixture in a PTFE vessel by heating for 24-48 h at 230 "C. The direct analysis of high-purity ceramics by LA-ICP-MS has been reported in conference presentations in recent years (see J.Anal. At. Spectrom. 1991 6 318R and references therein). Some of this important work is now being published in the primary literature. The technique has been applied to the analysis of silicon nitride powders (92/ 125 1 ) and to the trace analysis of cerium oxide silicon nitride and silicon carbide (92/1361). Two other papers also indicated application of LA-ICP-MS to the analysis of ceramics but no details were available in the abstracts (92/15 10 92/1579). The advantages of LA-ICP-MS cited included high sensitivity (sub-ppm) rapid analysis low background and minimal spectral interference and little or no sample preparation. A review of the analysis of ceramics by LA-FTMS may be of interest in the above context (92/ 1428). A number of conference papers have appeared in the last year describing the use of GD techniques for the characteri- zation of ceramic materials.Few analytical details are provided in these abstracts but the development of r,f powered GD sources has opened up real possibilities for application to the direct anal-vsis of ceramic insulators. Examples have included the use of r.f. GD sources for AES (9 1/3608 911C3723 92/C559 92/C3526) and MS (9 l/C3724 92/C3526). The move towards cell geometries accommodating flat samples instead of the older pin type configurations represents a significant step forward in a move towards the practical application of the technique in the ceramics field (911C3724 91/C3731).JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY DECEMBER 1992 VOL.7 385R LOCATION OF REFERENCES The full list of references cited in this Update have been published as follows 9113585-9114050 J. Anal. At. Spectrorn. 1991 6(8) 323R-340R. 9211-921425 J. Anal. At. Spectrom. 1992 7( I) 53R-66R. 92lC426-9211447 J. Anal. At. Spectrom. 1992 7(3) 1 19R-154R. 9211448-9212589 J. Anal. At. Spectrorn. 1992 7(4) 173R-2 13R. 9212590-92lC3494 J Anal. At. Spectrom. 1992 7( 5) 247R-277R. 92lC3495-9214073 J. Anal. At. Spectrom. 1992 7(7) 329R-348R. Abbreviated forms of the literature references quoted (excluding those to Conference Proceedings) are given on the following pages for the convenience of the readers. The full references names and addresses of the authors and details of the Conference presentations can be found in the appropriate issues of JAAS cited above.Abbreviated List of References Cited in Update 9113053. Zavod. Lab. 1990 56(4) 40. 9113587. J. Anal. At. Spectrom. 1991 6 205. 9113589. J. Anal. At. Spectrom. 1991 6 2 15. 9113590. J. Anal. At. Spectrom. 1991 6 22 1. 9113598. Analyst 1991 116 51 1. 9113599. Analyst 1991 116 5 17. 9113608. Spectrochim. Acta Part B 199 1,46,483. 9113773. J. Anal. At. Spectrom. 1991 6 261. 9113795. Fresenius J Anal. Chem. 199 1 339 133. 9113797. Fresen- ius J. Anal. Chem. 1991 339 226. 9113806. Spectrochim. Acta Part B 1991 46 183. 9113810. Spectrochim. Acta Part B 199 1 46 309. 9113812. Spectrochim. Acta Part B 1991 46 407. 9113817. Zh. Anal. Khim. 1991 46 175.9113821. X-Ray Spectrom. 1991 20 29. 9113852. Yejin Fenxi 1990 10(4) 23. 9113855. Bunseki Kagaku 1990,39 283. 9113856. Bunseki Kagaku 1990 39 T65. 9113858. Bunseki Kagaku 1990 39 T83. 9113859. Bunseki Kagaku 1990 39 497. 9113864. Bunseki Kagaku 1991 40 33. 9113868. Appl. Spectrosc. 1990 44 9 1. 9113878. Appl. Spectrosc. 199 1 45 242. 9113882. Anal. Chim. Acta 199 1 242 99. 9113889. J. Pharm. Biomed. Anal. 1990 8 975. 9113891. Isotopenpraxis 1990 26 488. 9113904. Vysoko- chist. Veshchestva 1990 6 173. 9113907. J. Chromatogr. Sci. 1991 29 98. 9113908. J. Chromatogr. Sci. 1990 28 175. 9113909. J. High Resolut. Chromatogr. 199 1 14 1 10. 9113911. J. Chem. SOC. Pak. 1990 12 249. 9113917. Fenxi Huaxue 1990 18 955. 9113922. 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