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The paper presents a usage of a new hyphenated technique, wherein a Multi–mode Sample Introduction System (MSIS) was applied as an interface of two high pressure liquid chromatography units and inductively coupled plasma optical emission spectrometry (2 HPLC–MSIS–ICP–OES). Simultaneous separation and detection of non–hydride forming and hydride forming elements was possible due to the application of two different HPLC column, cation–exchange and anion–exchange respectively. The method was able to determine 15 elements quantitatively with a distinction of three arsenic and two iron species and it was validated obtaining acceptable LODs (2.67–28.7 μg L−1) and recoveries (80–120%). The method applicability was presented and confirmed on 5 varied sample matrix types i.e. post–glacial sediments, yerba mate (Ilex paraguariensis), soil samples located in the proximity of industry wastes disposal site, river sediments, and archaeological pottery. In addition to the above, unknown Cu, Fe, Mn and Zn species were detected in real samples (qualitative speciation analysis) and the identification was attempted according to the literature.

In this study, we developed and compared three different methods for chromium speciation in water samples using microfluidic paper-based analytical devices (μPADs). In all methods, detection was based on the complexation reaction of Cr(VI) with diphenylcarbazide on the μPADs. Cr(III) ions were oxidized to Cr(VI) by Ce(IV) prior to colorimetric detection on the μPADs. In the first method, oxidization of Cr(III) to Cr(VI) in the solution containing both trivalent and hexavalent chromium was performed using a batch procedure to obtain total chromium. A dual electromembrane extraction (DEME) technique for simultaneous preconcentration and extraction of chromium species and a single electromembrane extraction (SEME) for preconcentration and extraction of Cr(VI)/total chromium [quantified as Cr(VI) content after oxidation of Cr(III) ions to Cr(VI)] were used in the second and third methods, respectively. The electromembrane extraction was based on the electrokinetic migration of cationic Cr(III) and anionic Cr(VI) toward the cathode and anode, respectively, into the two different hollow fibres. Octanol-1 and bis(2-ethylhexyl) phosphate (DEHP) in octanol-1 (0.7% v/v) were the most suitable supported liquid membranes for extraction of Cr(VI) and Cr(III), respectively. Among these methods, SEME showed the lowest limits of detection for both analytes. Under optimized conditions, linear calibrations were obtained for Cr(III) from 3 to 30 μg L−1 and for Cr(VI) from 3 to 70 μg L−1. The detection limits were 1.0 μg L−1 and 0.7 μg L−1 for Cr(III) and Cr(VI), respectively. Our developed method was applied to analyse water samples spiked with different concentrations of Cr(III) and Cr(VI) at the parts-per-billion (ppb) level. The statistical evaluation showed that the proposed method agreed well with the validation method, i.e., inductively coupled plasma atomic emission spectroscopy (ICP-AES).

An unsupervised data-driven methodology is used to quantify matrix effects caused by carbon and easily ionizable elements (EIEs) in inductively coupled plasma optical emission spectrometry (ICP OES). Background signals from nine plasma naturally-occurring species of Ar, H and O are used with principal component analysis (PCA) and affinity propagation (AP) clustering to evaluate the effects of complex matrices on ionic emission lines of Cd, Co, Cr and Pb. Matrix effect severity is then quantified based on Euclidean distance in principal component space from an average calibration curve point. The method has been applied to spiked solutions of Mediterranean Sea and Dead Sea water samples, and a significant correlation (- 0.997) was found between Euclidean distance and analyte recoveries. For sea water analysis, accurate results are found using external standard calibration (EC) when Euclidean distance 1 for a given sample, and/or when that sample point groups with the calibration curve after affinity propagation clustering. Thus, by applying the PCA-AP strategy, one needs to perform no addition/recovery experiment to evaluate EC applicability. In addition, it can be carried out on the fly, as the background species used to monitor plasma changes are simultaneously recorded with the analytical signals, and a specific algorithm can be added to the instrument control software to flag instances in which EC may be ineffective. This is a proof-of-concept study, and additional work is required to evaluate the method's applicability to a larger number of analytes and sample matrices. However, the PCA-AP method described here for ICP OES can be used to quantify matrix effects, allowing for informed decisions regarding calibration. It requires no additional sample preparation and can be easily implemented in routine analyses of such complex-matrix samples as sea water.

Several species are simultaneously used for internal standardization to improve accuracy in inductively coupled plasma optical emission spectrometry (ICP-OES). In multi-internal standard calibration (MISC), signal ratios between the analyte and each of several internal standard species are used for calibration. A single calibration solution is required, and the MISC graph is built with intensity ratios calculated with analytical signals recorded for the sample (IA,sam) on the y-axis, while those recorded for the calibration standard (IA,std) are plot on the x-axis (i.e. IA,sam/IIS(i) vs. IA,std/IIS(i), where IIS(i) represents the signal intensity for a given internal standard species). Nine analytes (As, Cd, Cr, Cu, Fe, Mg, Mn, Pb and Zn), and two sets of internal standard species (i.e. Bi, Ge, In, Rh, Sc, Te, Tl and Y in solution, or eighteen emission lines from plasma naturally occurring Ar) were evaluated in this proof-of-concept study. The MISC method's efficiency was evaluated by analyte addition and recovery experiments and by analyzing two certified reference materials. Figures of merit for MISC (limit of detection, repeatability and trueness) were comparable to those obtained for the traditional external standard calibration (EC) and internal standard (IS) methods. Different from IS, MISC requires no time-consuming study to identify an ideal internal standard species, and signal biases are minimized by an averaged, more encompassing internal standardization effect.

Advanced materials such as complex metal oxides are used in a wide range of applications and have further promising perspectives in the form of thin films. The exact chemical composition essentially influences the electronic properties of these materials which makes correct assessment of their composition necessary. However, due to high chemical resistance and in the case of thin films low absolute analyte amounts, this procedure is in most cases not straightforward and extremely time-demanding. Commonly applied techniques either lack in ease of use ( i.e. , solution-based analysis with preceding sample dissolution), or adequately accurate quantification ( i.e. , solid sampling techniques). An analysis approach which combines the beneficial aspects of solution-based analysis as well as direct solid sampling is Laser Ablation of a Sample in Liquid (LASIL). In this work, it is shown that the analysis of major as well as minor sample constituents is possible using a novel online-LASIL setup, allowing sample analysis without manual sample handling after placing it in an ablation chamber. Strontium titanate (STO) thin layers with different compositions were analyzed in the course of this study. Precision of the newly developed online-LASIL method is comparable to conventional wet chemical approaches. With only about 15–20 min required for the analysis per sample, time demand is significantly reduced compared to often necessary fusion procedures lasting multiple hours.

A simple, fast, sensitive and green pretreatment method for determination of Cd, Co, Hg, Ni, Pb and V in oral and parenteral drug samples using inductively coupled plasma optical emission spectrometry (ICP OES) has been developed. According to United States Pharmacopoeia (USP), those metals must be reported in all pharmaceutical products for quality control evaluation (i.e., elemental impurities from classes 1 and 2A of USP Chapter 232). To improve the analytical capabilities of ICP OES, a dispersive liquid-liquid microextraction (DLLME) has performed using a safe, cheap and biodegradable deep eutectic solvent (DES) as extractant solvent (a mixture of 2:1 molar ratio of DL-menthol and decanoic acid). Seven parameters affecting the microextraction efficiency have carefully optimized by multivariate analysis. Under optimized conditions, the DES-based DLLME-ICP OES procedure improved limit of quantitation (LOQ) values on range from 12 to 85-fold and afforded an enrichment factor on average 60-times higher than those obtained to direct ICP OES analysis. Consequently, LOQ values for Cd, Co, Hg, Ni, Pb and V have been on average 10-times lower than target limits recommended for drugs from parenteral route of administration. Trueness has evaluated by addition and recovery experiments following USP recommendations for three oral drug samples in liquid dosage form and three parenteral drugs. Recovery and RSD values have been within the range of 90-109% and 1-6%, respectively. All analytes were below the repectives LOQ values, hence, lower than the limits proposed by USP Chapter 232. The authors are grateful to the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, grants no. 141634/2017-0, 202722/2019-8, 305201/2018-2 and 428558/2018-6), the Ministry of Economy and Competitiveness of Spain (PGC2018-096616-B-I00) the Regional Government of Valencia (Spain) (PROMETEO/2018/087, ACIF/2020/186), and University of Alicante (VIGROB-316FI) for the financial support, Agilent Technologies Inc. for the loan of the ICP OES spectrometer, and Ingeniatrics for the OneNeb® Series 2 provided. This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001. The authors extend their appreciation to Ministry of Science, Innovation and Universities for granting the Spanish Network of Excellence in Sample Preparation (RED2018-102522-T). This article is based upon work from the Sample Preparation Study Group and Network, supported by the Division of Analytical Chemistry of the European Chemical Society.

A simple and highly efficient method for the determination of highly toxic arsenic species using non-covalently aminated silica is proposed. The polyamines including poly(hexamethyleneguanidine), poly(4,9-dioxadodecane-1,12-guanidine), hexadimethrine, and poly(diallyldimethylammonium) were tested as silica modifiers. The prepared adsorbents allow effective preconcentration of anionic species of arsenic from aqueous solutions. It was found that As(V) can be quantitatively extracted from solutions at pH 4.5–7.0 by the anion exchange mechanism in less than 5 min, while neutral at this pH As(III) was not adsorbed at these conditions. A reaction with 2,3-dimercapto-1-propanesulphonic acid, which resulted in the formation of the negatively charged complex of As(III) with adsorbents was used for its quantitative extraction from solutions with a pH of 3.5–6.5. A system of two cartridges filled with poly(diallyldimethylammonium) modified silica and the on-line reaction of As(III) with 2,3-dimercapto-1-propanesulphonic acid proceeding between the cartridges was used for separate preconcentration and determination of As(V) and As(III) at pH 5. The proposed method was used for four-year monitoring of natural water pollution by arsenic in the area of residence of the indigenous peoples of Tyva Republic (Russia).

Made available in DSpace on 2018-12-11T16:48:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-08-22 Agilent Technologies Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Multi-energy calibration (MEC) is a novel strategy that explores the capacity of several analytes of generating analytical signals at many different wavelengths (transition energies). Contrasting with traditional methods, which employ a fixed transition energy and different analyte concentrations to build a calibration plot, MEC uses a fixed analyte concentration and multiple transition energies for calibration. Only two calibration solutions are required in combination with the MEC method. Solution 1 is composed of 50% v v−1 sample and 50% v v−1 of a standard solution containing the analytes. Solution 2 has 50% v v−1 sample and 50% v v−1 blank. Calibration is performed by running each solution separately and monitoring the instrument response at several wavelengths for each analyte. Analytical signals from solutions 1 and 2 are plotted on the x-axis and y-axis, respectively, and the analyte concentration in the sample is calculated from the slope of the resulting calibration curve. The method has been applied to three different atomic spectrometric techniques (ICP OES, MIP OES and HR-CS FAAS). Six analytes were determined in complex samples (e.g. green tea, cola soft drink, cough medicine, soy sauce, and red wine), and the results were comparable with, and in several cases more accurate than, values obtained using the traditional external calibration, internal standardization, and standard additions methods. MEC is a simple, fast and efficient matrix-matching calibration method. It may be applied to any technique capable of simultaneous or fast sequential monitoring of multiple analytical signals. Group for Applied Instrumental Analysis Department of Chemistry Federal University of São Carlos, P. O. Box 676 Department of Physics and Chemistry UNESP-Univ Estadual Paulista, Av. Brasil, 56 Agilent Technologies, 2500 Regency Parkway Department of Analytical Chemistry UNESP-Univ Estadual Paulista, P.O. Box 355 Department of Chemistry Wake Forest University, Salem Hall, Box 7486 Department of Physics and Chemistry UNESP-Univ Estadual Paulista, Av. Brasil, 56 Department of Analytical Chemistry UNESP-Univ Estadual Paulista, P.O. Box 355 CAPES: 99999.002566/2014-01

The recent commercialisation of inductively coupled plasma tandem mass spectrometric (ICP-MS/MS) instruments has provided analytical chemists with a new tool to properly quantify atomic composition in a variety of matrices with minimal sample preparation. In this article, we report on our assessment of the compatibility of 3 sample preparation techniques (open-vessel acid digestion, microwave digestion and alkaline fusion) for the quantification of rare earth elements (REEs) in mineral matrices. The combination of the high digestion temperatures (1050 °C) and using LiBO2 as a flux was the most effective strategy for the digestion of all rare earth elements in mineral matrices and was compatible with ICP-MS/MS measurements. We also assessed the analytical performances of ICP-MS/MS against other plasma-based instrumentation (microwave induced plasma and inductively coupled plasma atomic emission spectroscopy (MIP-AES and ICP-AES, respectively) and single quadrupole inductively coupled plasma mass spectrometry (ICP-MS). The comparative study showed that the concentrations obtained by ICP-MS/MS are in excellent agreement with the certified reference material values, and much more suited than the other analytical techniques tested for the quantification of REEs, which exhibited low detectability and/or spectral interferences for some elements/isotopes. Finally, the ruggedness of the analytical protocol proposed which combines a rapid sample dissolution step performed by an automated fusion unit and an ICP-MS/MS as a detector was established using various certified mineral matrices containing variable levels of REEs.

The effect of different interfering elements, i.e., Na, K, Mg, Ca, Al, Cu, Fe, Mn, Ni, and Zn, on the analytical performance of flowing liquid anode atmospheric pressure glow discharge optical emission spectrometry (FLA-APGD OES) was extensively studied. In the presence of interfering ions, the emission from analytes was suppressed by ∼10% in the case of Hg and Tl, ∼20% for Cd and Ag, and up to ∼80% for Zn and Pb. This study revealed that interfering elements did not affect the atomization/excitation conditions, and the reason for the observed decrease in analytical response was the impaired efficiency of analytes transport from liquid to plasma phase. To reduce matrix effects, the use of different masking agents capable of complexing the interfering ions, e.g., organic acids, crown ethers, chelating agents, and other compounds, was investigated. FLA-APGD appeared to be quite susceptible to the presence of masking agents and only their small amounts could be added (limiting the effectiveness of this approach). Despite this, it was possible to significantly reduce the matrix effects originating from transition metals and alkali/alkaline earth metals. Based on the results presented herein, different sample treatment procedures, aimed at the minimization of matrix effects in microplasma excitation sources, can be developed. As an example, a method for the determination of trace amounts of Zn and Pb in the Fe-rich matrix has been shown. By the use of the selected masking agents, the recovery of Zn and Pb was improved 5.6-fold (from 10.4 to 57.8%) and 2.8-fold (from 13.6 to 38.0%), respectively. Despite the presence of Fe-rich matrix, the detection limits of Zn and Pb were quite low (0.1 and 0.8 μg L−1, respectively) and they were apparently lower than offered by ICP OES.

The analysis of siliceous matrix samples may adopt a two-step pretreatment, which includes melting with ammonium hydrogen fluoride and redissolving with nitric acid. However, the residual of substrate silicon unfavorable to the determination of trace elements in the samples due to serious matrix effects. Here, a new digestion method using simultaneously both ammonium bifluoride and nitric acid under normal pressure was developed for high-purity quartz sand sample. The digestion pretreatment is a two step process: melting/dissolving with both ammonium bifluoride and nitric acid at 200 °C for 2 h, and evaporating the solution at 250 °C to dryness. As confirmed by XRD analysis, silicates in the sample were converted to (NH4)3SiF6NO3 in the melting/dissolving step. TGA analysis shows that the generated (NH4)3SiF6NO3 could be decomposed and evaporated completely at 250 °C, which ensured a complete removal of silicon by the followed evaporation of the solution at 250 °C. As a result, the followed ICP-OES and ICP-MS analysis needed a solution dilution of only 100 times for the determination of Ca, Mg, Al, Rb, Ba, REE and other trace elements. The new method was applied to the analysis of three certified reference materials, and the results were well consistent with the standard value with RSD% values between 0.62% and 9.73%. Therefore, this method can be applied to the analysis of trace elements in high purity silica-based samples, with the advantages of time-saving, small dilution factor (only 100 times) and low detection limit.

This work proposed a procedure for microwave-assisted sample preparation of medicines using diluted nitric acid followed by determination of elemental impurities using inductively coupled plasma optical emission spectrometry (ICP OES) and inductively coupled plasma mass spectrometry (ICP-MS) according to the United States Pharmacopeia Chapters 232 and 233. Three solutions, i.e. inverse aqua regia, 7.0 and 2.0 mol L−1 HNO3, were evaluated for microwave-assisted digestion of nine drugs samples. The applicability of each digestion procedure was assessed by comparison of analyte concentrations determined using total (reference procedure) and partial digestions (proposed procedure) as well as by determining dissolved carbon content and evaluating matrix effects. There were none significant differences at a 95% confidence level among the concentrations determined applying reference and proposed procedures. Internal standardization (ICP OES) and aerosol dilution (ICP-MS) were applied for minimization and correction of matrix effects. Addition and recovery experiments were performed according to oral permissible daily exposures values specific for each element and each sample was spiked with element concentrations of 0.5J and 1.5J in order to check accuracies for 24 analytes. Recoveries ranged from 70 to 138% for ICP OES and from 72 to 128% for ICP-MS, for all elements but Os. All analytes were below the respective limits of quantification when applying all sample preparation procedures, except As, Ba, Co, Cu, Cr, Mo, Ni, Pb, Sb, Sn, Tl and V, however the determined concentrations for these elements were lower than the limits proposed by Chapter 232.

Mobile phones are one of the fastest growing types of electronic waste disposed of world-wide. One of the main components in these devices is the LCD (liquid crystal display) panel that contains conductive electrodes made of indium tin oxide. A large amount of In, which is categorized as a critical raw element, has been used to manufacture indium tin oxide films. This study applies laser-induced breakdown spectroscopy (LIBS) for the analysis of LCD samples from mobile phones in order to determine the In content. Both conventional univariate calibration and non-traditional calibration using different transition energies (emission lines), named multi-energy calibration (MEC), were assessed. To evaluate the accuracy of the results, Method EPA 3052 was performed for acid digestion of the samples using microwave-assistance, and the In content was determined by ICP OES. Indium concentrations ranged from 35 to 47 mg kg−1 for all samples evaluated. The results showed the best accuracy for LIBS methods after the spectra were normalized by the carbon line at 193.09 nm. The univariate-LIBS model showed a standard error of calibration (SEC) about 10-fold lower than the samples’ concentration, LOD and LOQ of 0.3 and 1.0 mg kg−1, respectively. MEC proved to be a fast and efficient alternative for direct solid analysis, and In concentrations were determined by LIBS using only two calibration pellets. The LOD and LOQ for MEC-LIBS method were 2.1 and 7 mg kg−1, respectively.

An automatic flow-through dynamic extraction method is proposed for the first time for in vitro exploration, with high temporal resolution, of the transit of the chyme from the gastric to the duodenal compartment using the Versantvoort's fed-state physiologically relevant extraction test. The flow manifold was coupled on-line to an inductively coupled plasma optical emission spectrometer (ICP OES) for real-time elucidation of the bioaccessible elemental fraction of micronutrients (viz., Cu, Fe and Mn) in food commodities across the gastrointestinal tract. The simulated intestinal and bile biofluid (added to the gastric phase) was successively pumped at 1.0 mL min−1 through a large-bore column (maintained at 37.0 ± 2.0 °C) initially loaded with a weighed amount of linseed (250 mg) using a PVDF filter membrane (5.0 μm pore size) for retaining of the solid sample and in-line filtration of the extracts. The lack of bias (trueness) of the on-line gastrointestinal extraction method coupled to ICP OES was confirmed using mass balance validation following microwave assisted digestion of the residual (non-bioaccessible) elemental fraction. Mass balance validation yielded absolute recoveries spanning from 79 to 121% for the overall analytes and samples. On-line dynamic extraction was critically appraised against batch counterparts for both gastric and gastrointestinal compartments. Due to the lack of consensus in the literature regarding the agitation method for batch oral bioaccessibility testing, several extraction approaches (viz., magnetic stirring, end-over-end rotation and orbital shaking) were evaluated. Improved gastric extractability of Fe along with bioaccessible data comparable to the dynamic counterpart based on the continuous displacement of the extraction equilibrium was obtained with batchwise magnetic stirring, which is deemed most appropriate for ascertaining worst-case/maximum bioaccessibility scenarios.

Absract To understand the formation of plumbane in the Pb II -NaBH 4 -K 3 Fe(CN) 6 system, the intermediate products produced in the reaction of lead(II) and NaBH 4 in the presence of K 3 Fe(CN) 6 were studied. The produced plumbane and elemental lead were measured through continuous flow hydride generation (HG)-inductively coupled plasma optical emission spectrometry (ICP OES) and X-ray diffraction spectrometry techniques, respectively. Based on the experimental results, the explanations can be depicted in the following steps: (1) plumbane and black lead sediment (black Pb) are formed in the reaction of lead(II) and NaBH 4 ; (2) the black Pb is oxidized by K 3 Fe(CN) 6 to form Pb 2 [Fe(CN) 6 ], which further reacts with NaBH 4 to form more plumbane and black Pb; and (3) another round starts in which the produced black Pb from the step 2 is then oxidized continuously by K 3 Fe(CN) 6 to form more Pb 2 [Fe(CN) 6 ] complex, which would produce more plumbane. In short, the black Pb and Pb 2 [Fe(CN) 6 ] complex are the key intermediate products for the formation of plumbane in the Pb II -NaBH 4 -K 3 Fe(CN) 6 system. Based on the enhancement effect of potassium ferricyanide and potassium ferrocyanide, a method was developed to analyze lead in milk with HG-ICP OES technique. The detection limit of the method was observed as 0.081 μg L −1 . The linearity range of lead was found between 0.3 and 50,000 μg L −1 with correlation coefficient of 0.9993. The recovery of lead was determined as 97.6% ( n = 5) for adding 10 μg L −1 lead into the milk sample.

Within the last decade, liquid-phase microextraction (LPME) and micro-solid phase extraction (μSPE) approaches have emerged as substitutes for conventional sample processing procedures for trace metal assays within the framework of green chemistry. This review surveys the progress of the state of the art in simplification and automation of microextraction approaches by harnessing to the various generations of flow injection (FI) as a front end to atomic absorption spectrometry (AAS), atomic fluorescence spectrometry (AFS) or inductively coupled plasma atomic emission spectrometry or mass spectrometry (ICP-AES/MS). It highlights the evolution of flow injection analysis and related techniques as vehicles for appropriate sample presentation to the detector and expedient on-line matrix separation and pre-concentration of trace levels of metals in troublesome matrices. Rather than being comprehensive this review is aimed at outlining the pros and cons via representative examples of recent attempts in automating green sample preparation procedures in an FI or sequential injection (SI) mode capitalizing on single-drop microextraction, dispersive liquid-phase microextraction and advanced sorptive materials including carbon and metal oxide nanoparticles, ion imprinted polymers, superparamagnetic nanomaterials and biological/biomass sorbents. Current challenges in the field are identified and the synergetic combination of flow analysis, nanotechnology and metal-tagged biomolecule detection is envisaged.

Three typical schemes for metal fractionation were applied to analyse coastal surface sediment samples from Bahía Blanca estuary, where an important industrial emplacement is located. Also, three certified reference materials for total metal concentrations were analysed. The studied metals were cadmium, chromium, copper, lead and zinc because of their hazardous potential and related abundance in the estuary. The concentration of metals was determined by inductively coupled plasma-optical emission spectrometry (ICP-OES). A three-way multivariate analysis was performed in order to obtain a better visualization of the experimental data. The extracted information was used to evaluate the equivalence among the results obtained by the three sequential extraction schemes. The data were analysed by parallel factor analysis (PARAFAC). PARAFAC models with two factors describe appropriately the data sets (explained variance about 54% and core consistency of 100%). The multivariate decomposition showed that the three applied schemes are able to describe equally well the behaviour of the metals in the different sediment fractions.

A method for the separation of tetrachloroplatinate PtCl(4)(2-), and hexachloroplatinate PtCl(6)(2-), by solid-phase extraction, using a Dowex 1x10 anion exchange resin is proposed. The sequential elution and separation of PtCl(4)(2-), and PtCl(6)(2-) is achieved using selective complexing agents. The eluates, containing Pt(II) and Pt(IV) were analyzed by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Recoveries of 102% for PtCl(4)(2-) and 94% for PtCl(6)(2-) and detection limit of 15 ng g(-1) were achieved. Using this method determination of Pt(II) and Pt(IV) in soil samples, spiked with different platinum species was performed. The comparison with GFAAS determination showed a very good agreement.

Utilising extremely different vaporisation properties of boron compounds, the determination procedures of volatile boric acid and total boron using tungsten boat furnace (TBF) ICP-MS and TBF-ICP-AES have been investigated. For the determination of volatile boric acid by TBF-ICP-MS, tetramethylammonium hydroxide (TMAH, Me(4)NOH) was used as a chemical modifier to retain it during drying and ashing stages. As for the total boron, not only non-volatile inorganic boron such as boron nitride (BN), boron carbide (B(4)C), etc. but also boric acid (B(OH)(3)) was decomposed by a furnace-fusion digestion with NaOH to produce sodium salt of boron, a suitable species for the electrothermal vaporisation (ETV) procedure. The proposed method was applied to the analysis of various standard reference materials. The analytical results for various biological and steel samples are described.

A study was undertaken to ascertain the analytical capabilities of l-methionine immobilized on controlled pore glass for Sb preconcentration and speciation. A fully automated on-line system, implemented with hydride generation (HG) and inductively coupled plasma optical emission spectrometry (ICP OES), was used. Sb(III), at pH 10 was selectively retained in the column containing the immobilized aminoacid, while Sb(V) was not retained at all. A 30% HCl solution was used as eluent agent. Prior to total Sb determination, a pre-reduction step with thiourea was necessary. An on-line pH adjusting and pre-reduction of Sb(V) was achieved in a fully automated system. The detection limit for the preconcentration of 10 mL of an aqueous solution was 70 ng L-1 with a relative standard deviation of 2%. An enrichment factor of 20 was achieved when 10 mL of sample was passed through the system, reaching a throughput of 23 samples per hour. The method was successfully applied to the determination of Sb(III) and total Sb in urine. Fil: Pacheco, Pablo Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina. Ministerio de Ciencia, Tecnología e Innovación Productiva. Agencia Nacional de Promoción Científica y Tecnológica. Fondo para la Investigación Científica y Tecnológica; Argentina Fil: Gil, Raul Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina Fil: Martinez, Luis Dante. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina Fil: Polla, Griselda Ines. Comisión Nacional de Energía Atómica; Argentina Fil: Smichowski, Patricia Nora. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; Argentina

This review describes the different steps involved in the determination of arsenic in air, considering the particulate matter (PM) and the gaseous phase. The review focuses on sampling, sample preparation and instrumental analytical techniques for both total arsenic determination and speciation analysis. The origin, concentration and legislation concerning arsenic in ambient air are also considered. The review intends to describe the procedures for sample collection of total suspended particles (TSP) or particles with a certain diameter expressed in microns (e.g. PM10 and PM2.5), or the collection of the gaseous phase containing gaseous arsenic species. Sample digestion of the collecting media for PM is described, indicating proposed and established procedures that use acids or mixtures of acids aided with different heating procedures. The detection techniques are summarized and compared (ICP-MS, ICP-OES and ET-AAS), as well those techniques capable of direct analysis of the solid sample (PIXE, INAA and XRF). The studies about speciation in PM are also discussed, considering the initial works that employed a cold trap in combination with atomic spectroscopy detectors, or the more recent studies based on chromatography (GC or HPLC) combined with atomic or mass detectors (AFS, ICP-MS and MS). Further trends and challenges about determination of As in air are also addressed.

A procedure has been developed for the simultaneous determination of traces amounts of Cd, Cr, Cu, Mn, Ni and Pb from saline oil-refinery effluents and digested vegetable samples using inductively coupled plasma optical emission spectrometry (ICP OES). The procedure is based on cloud point extraction (CPE) of these metals as 2-(bromo-2-pyridylazo)-5-diethyl-amino-phenol (Br-PADAP) complexes into a micellar phase of octylphenoxypolyethoxyethanol (Triton X-114). Optimization of the procedure was performed by response surface methodology (RSM) using a Doehlert design. Principal components (PC) were used to simplify the multiple response analysis. A response surface for the first PC score is useful in determining the optimum conditions for the Cd, Cr, Cu, Mn and Pb determinations whereas the second PC is highly correlated with the Ni response. Improvement factors of 22, 36, 46, 25, 65 and 39, along with limits of detection (3 σ B ) of 0.081, 0.79, 0.38, 0.83, 0.28 and 0.69 μg L −1 , and precision expressed as relative standard deviation (%R.S.D., n = 8, 20.0 μg L −1 ) of 1.5, 2.2, 3.5, 2.6, 2.5 and 2.5 were achieved for Cd, Cr, Cu, Mn, Ni and Pb, respectively. The accuracy was evaluated by spike tests in oil-refinery effluent samples and analysis of a vegetable certified reference material (NIST 1571, orchard leaves). Results found were in agreement with certified values.

The method of ultrasound-assisted extraction followed by inductively coupled plasma optical emission spectrometry (ICP-OES) used for the determination of trace element concentrations (arsenic, copper, lead, antimony, and zinc) in shooting range areas was optimized. Optimization was achieved not only on the basis of the analysis of appropriate standard reference materials but also on that of 31 synthetic mixtures of matrix and analyte elements (aluminum, antimony, arsenic, calcium, copper, lead, iron, manganese, silicon, and zinc), in five concentrations. All the measurements were performed in robust plasma conditions which were tested by measuring the Mg II 280.270 nm/Mg I 285.213 nm line intensity ratio. The highest Mg II 280.270 nm/Mg I 285.213 nm line intensity ratios were observed when a nebulizer gas flow of 0.8 L min −1 , auxiliary gas flow of 0.2 L min −1 and plasma power of 1400 W were used for both the axially and radially viewed plasmas. The analysis of 31 synthetic mixtures of the selected elements showed that As concentrations could be accurately determined with axially viewed plasma alone. The determination of Pb and Sb could be performed with either axially or radially viewed plasma whereas, surprisingly, Cu could be determined with high accuracy using radial plasma alone with a power of 1400 W. All the elements investigated were determined with high accuracy using robust plasma conditions and a combination of axially and radially viewed plasmas. The total recoveries of elements from SRM 2710 (Montana soil) and SRM 2782 (Industrial sludge) were highly comparable to leach recoveries certified by the National Institute of Standards and Technology (NIST).

A study of the trace metal distribution in sediment samples from the Galician coast (Spain) has been performed. A multielement extraction method optimised via experimental design has been employed. The method uses centrifugation to pass the extractant solution at varying pH, through the sediment sample. The sequential leaches were collected and analysed by ICP-AES. Chemometric approaches were utilised to identify the composition of the physico-chemical components in order to characterise the sample. The samples collected at different sites could be classified according to their differences in metal bio-availability and important information regarding element distribution within the physico-chemical components is given. The method has proved to be a quick and reliable way to evaluate sediment samples for environmental geochemistry analysis. In addition, this approach has potential as fast screening method for the bio-availability of metals in the environment.

Analysis in a single particle mode of gold colloids in water has been performed by inductively coupled plasma-mass spectrometry (ICP-MS). The signal induced by the flash of ions due to the ionizati ...

In the absence of a standard wet preparation method for the determination of inorganic elements in peat, four acid digestion methods (nitric acid (HNO 3 ), HNO 3 /hydrochloric acid (HCl), aqua regia and HNO 3 /hydrofluoric acid (HF)) were compared using a Canadian fen peat (OGS 1878 P-6), previously proposed as a reference material, and inductively coupled plasma-optical emission spectrometry (ICP-OES) as the instrumental analytical technique. Two microwave-assisted methods, HNO 3 and HNO 3 /HF, representing ‘acid-extractable’ and total digestion, respectively, were then selected for optimisation and application to a newly developed ombrotrophic peat reference material (NIMT/UOE/FM/001) and to the individual sections of a 43 cm peat core, also from Flanders Moss, Scotland, for a range of elements, including Al, Co, Cr, Cu, Fe, Mn, P, Pb, S, Ti, V and Zn. While the results suggested the general efficacy of HNO 3 in investigations of the greatly elevated levels of trace elements, such as Cu, Pb and Zn, resulting from the severe anthropogenic contamination of the environment during the industrial era, the need for addition of HF for the determination of major lithogenic elements, such as Al and Ti, present in aluminosilicates and other resistant minerals, and some trace elements (Co, Cr and V) was clearly demonstrated. The inclusion of HF in a total digestion method, such as HNO 3 /HF, is, therefore, necessary when normalisation of trace element concentrations to those of a conservative lithogenic reference element, such as Ti, is performed for the purpose of determining elemental enrichment factors. For elements other than Hg, the dry ashing of peat samples at 450 °C prior to acid digestion is recommended for the destruction of the predominantly organic matrix, especially relevant where inductively coupled plasma-mass spectrometry (e.g. quadrupole inductively coupled plasma-mass spectrometry (ICP-MS)) is to be used in the determination of the much lower concentrations of trace elements prevalent in pre-industrial and ancient times.

In this study an energy dispersive X-ray fluorescence (EDXRF) method has been applied to the analysis of some major and minor elements (K, Ca, Mn, Fe, Cu, Sr, Pb and Zn) in four higher plants growing on the waste landfills surrounding an abandoned Pb–Zn ore concentration factory. The validation of the procedure was performed by using a certified standard reference material (NIST SRM 1571: “Orchard leaves” from National Institute of Standards and Technology) and by comparison with data obtained from two routine microwave assisted digestion procedures commonly applied to vegetation specimens (Dig A: HNO 3 + H 2 O 2 , Dig B: HNO 3 + H 2 O 2 + HF) plus ICP-OES. No statistically significant differences at the 98% confidence level were found between EDXRF and Dig A results, concerning to Ca, Pb, Sr and Zn. On the contrary, statistically significant differences were found for K, Mn, Fe and Cu due to the presence of a silica residue. The addition of HF (Dig B) neither accomplishes the solubilization of these elements. After Dig B a solid residue is formed mainly composed by Ca and F, according to the results obtained by scanning electronic microscopy (SEM). Taking into account all these facts, the EDXRF method proposed proved to be an effective tool for metal determination in vegetation specimens since it allows obviating the matrix destruction stage and the poor recoveries for some elements.

Seven slurry preparation procedures were evaluated concerning the simultaneous determination of Hg and Se by on-line chemical vapor generation coupled to axial view ICP OES, using: (1) aqua regia and sonication; (2) HCl, sonication and heating at 90 °C; (3) tetramethylammonium hydroxide (TMAH); (4) H 2 O 2 , sonication, addition of HCl and heating at 90 °C; (5) K 2 S 2 O 8 , sonication, addition of HCl and heating at 90 °C (6) TMAH, sonication, ozonation, addition of HCl and heating at 90 °C; (7) Triton X-100, sonication, ozonation, addition of HCl and heating at 90 °C. The concentrations of HCl and NaBH 4 , used in the chemical vapor generation, in the different slurry media and in the slurry blanks, were optimized by factorial analysis. The calibrations were carried out using aqueous solutions in the same medium as the slurry, containing the analytes, Hg(II) and Se(IV), in the concentration range of 0.5–10 μg L −1 . The procedures were applied initially to the certified material TORT-2 (Lobster Hepatopancreas) and all of them produced results for Hg in agreement with the certified value, according to the t -test for a 95% confidence level. However, for Se, results in agreement with the certified value were obtained only when Procedures 4 and 5 were used, indicating that either H 2 O 2 or K 2 S 2 O 8 is required, most probably to break the Se bonds efficiently. Procedure 5, with detection limits (3 s, n = 10) of 0.08 μg g −1 for Hg and 0.10 μg g −1 for Se, for a sample mass of 20 mg in a final volume of 15 mL, was adopted and applied to the analysis of five certified reference biological materials and the tissues of six real oyster samples grown in the Santa Catarina Island coast. The obtained Hg and Se concentrations were in agreement with the certified values. The recommended procedure is simple, rapid and robust.

A study was undertaken to evaluate Saccharomyces cerevisiae as a substrate for the biosorption of Cr(III) and Cr(VI) aiming to the selective determination of these species in aqueous solutions. The yeast cells were covalently immobilised on controlled pore glass (CPG), packed in a minicolumn and incorporated in an on-line flow injection system. The effect of chemical and physical variables affecting the biosorption process was tested in order to select the optimal analytical conditions for the Cr retention by S. cerevisiae . Cr(III) was retained by the immobilised cells and Cr(VI) were retained by CPG. The speciation was possible by selective and sequential elution of Cr(III) with 0.05 mol L −1 HCl and 2.0 mol L −1 HNO 3 for Cr(VI). The influence of some concomitant ions up to 20 mg L −1 was also tested. Quantitative determinations of Cr were carried out by means of inductively coupled plasma optical emission spectrometry (ICP OES). Preconcentration factors of 12 were achieved for Cr(III) and 5 for Cr(VI) when 1.7 mL of sample were processed reaching detection limits of 0.45 for Cr(III) and 1.5 μg L −1 for Cr(VI). The speciation of inorganic Cr in different kinds of natural waters was performed following the proposed method. Spiked water samples were also analysed and the recoveries were in all cases between 81 and 103%.

A simple, robust and reliable analytical procedure for the determination of Al, Ca, Fe, K, Li, Mg, Mn, Na, Sr, Ti, and Zn in peat and plant materials by inductively coupled plasma-optical emission spectrometry (ICP-OES) was developed. A microwave heated high pressure autoclave was used to digest powdered sample aliquots (approximately 200 mg) with different acid mixtures including nitric acid (HNO 3 ), tetrafluoroboric acid (HBF 4 ) and hydrogen peroxide (H 2 O 2 ). The optimized acid mixture for digestion of plant and peat samples consisted of 3 mL HNO 3 and 0.1 mL HBF 4 , in addition to H 2 O 2 which was sub-boiled into the PTFE digestion tubes during heating of the autoclave. Using HNO 3 alone, recoveries of Al and Ti were too low by 40 and 160%, respectively, because HNO 3 could not fully liberate the analytes of interest from the silicate fraction of the plant and peat matrix. However, for all other elements (such as Mn, Sr, and Zn), the use of HBF 4 was less critical. The accuracy of the analytical procedure developed was evaluated with peat and plant reference materials of different origin and composition. The ICP-OES instrument was optimized using solutions of plant reference materials considering RF power, nebulizer pressure, auxiliary gas flow and rinse time. Scandium was used as an online internal standard (IS) as it provided accurate results and showed less than 3% drift in sensitivity over time which was lower compared to other potential IS such as Rh (20%) and In (6%). The combination of most sensitive and less sensitive wavelengths allowed to obtain low detection limits and highest possible dynamic range. The achieved procedure detection limits ranged from 0.05 μg g −1 (Li) to 15 μg g −1 (Ca) and allowed a precise quantification of all elements. Comparative X-ray fluorescence spectrometric measurements of solid peat and plant samples generally agreed well with results obtained by digestion/ICP-OES. To overcome interferences caused by Na, K, and Li, a solution of 10 μg g −1 CsCl 2 was successfully used as an ionization buffer. The good agreement between the found and certified concentrations in plant and peat reference materials indicates that the developed analytical procedure is well suited for further studies on the fate of major elements in plant and peat matrices.

The on-line column preconcentration technique with inductively coupled plasma optical emission spectroscopy (ICP–OES) has been developed using a cartridge filled with octadecyl silica modified by l-(2-pyridylazo) 2-naphtol (PAN). The aim of this method was to determine some rare earth elements (REEs) (Ce, Dy, La, Sm, and Y) and uranium in water samples. Sample solutions were passed through the C 18 -modified column. The adsorbed cations were subsequently eluted from the column and transferred into the plasma with nitric acid solution for simultaneous determination of them. Sample pH, amount of PAN as a complexing agent, sampling and eluting flowrates and concentration of the eluent were optimized. Detection limits based on three times of standard deviations of blank by 10 replicates were in the range of 11 ng l −1 for Dy to 69 ng l −1 for U. Sample throughput was 10 samples h −1 . The proposed method was applied to determine REEs in natural water samples. Recoveries of the REEs from natural water samples were between 95 and 106% with percent relative standard deviation (%R.S.D.) of 1.0–7.9%.

The distribution of aluminium (Al) species was investigated in the roots of Al-tolerant Chinese cabbage ( Brassica rapa L. ssp. pekinensis ) by employing fast protein liquid chromatography (FPLC) with inductively coupled plasma optical emission spectrometry (ICP-OES) and electrospray tandem mass spectrometry (ES–MS–MS) detection. The cabbage was exposed to a nutrient solution that contained 10 μg cm −3 of Al 3+ . The results demonstrated that after 24 h of exposure, Al was quantitatively taken up by the cabbage and was distributed in different parts of the plant. 36 ± 6% of total Al was located in the roots, while the remaining 64 ± 10% was transferred to the leaves. It was found that in the roots Al was partially present in the root sap (15.5%), while the majority (84.5%) was accumulated in its apoplasmic compartments. It was further demonstrated that the proportion of Al that entered the symplasm formed a complex with organic acid. Speciation analysis by FPLC with ICP-OES detection and ES–MS–MS identification of the binding ligand indicated that Al-citrate complex was the prevailing species in the root sap. The results of the present study showed that both immobilization of Al in the apoplasmic compartments of the roots and transformation of Al 3+ to Al-citrate are most likely responsible for the tolerance of Chinese cabbage ( B. rapa L. ssp. pekinensis ) to the toxic effects of Al 3+ .

A novel type of interface for gas removal has been developed for coupling a high-temperature/high-pressure online flow digestion system to an ICP spectrometry instrument. It consists of a porous polypropylene tube with an inner rod made of PEEK which causes the formation of a thin film (100 μm) of liquid at the inner surface of the porous tube, thereby considerably increasing the ratio of gas exchange area to liquid volume and simultaneously decreasing the dead volume. Thus very efficient removal of the gaseous reaction products, such as CO 2 and NO x , which are known to affect the ICP stability, was achieved. Even at high flow rates and with a high carbon content in the samples more than 99% of the gases were removed. Applying ICP–OES detection excellent recoveries were obtained for most elements except for Sb, Ag and Ga. Good agreement between certified and measured values was obtained for online determinations of elements in various biological and environmental standard reference materials. Low standard deviation and detection limits in the lower μg/g range were found. This new tube interface combines low costs with robust properties, compact design and ease of handling.

The application of ultrasound-assisted extraction procedure has been examined for the estimation of major, minor and trace elements in a set of bio-environmental samples (IAEA lichen 336 and mussel tissue NIST 2976) as a possible alternative to conventional digestion methods. Inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectrometry (ICP-AES) were used for the quantification of the elements. Parameters affecting extraction such as extractant concentration, sonication time and ultrasound amplitude were optimized to get quantitative recovery of elements. These studies indicate that the method is a fast (within 15 min including centrifugation time) and simple method for the estimation of Na, K, Ca, Mg, Cr, Mn, Co, Ni, Cu, Zn, Ge, As, Se, Rb, Sr, Zr, Ag, Cd, In, Sb, Cs, Ba, Pb and Bi. Quantitative recoveries for most of the elements for which certified concentrations available, were obtained using a 1% (v/v) HNO 3 as extractant and metal solubilization can be achieved within 4 min sonication time at 40% sonication amplitude and 100 mg sample weight. The supernatant obtained upon centrifugation was used for analysis. Quantitative recovery was achieved for many elements which are well in agreement with certified values. An overall precision of better than 10% could be achieved for many elements in multiple extractions. Similar extraction procedure was tested on two field lichen samples. Closed-microwave digestion method was also used for the estimation of various elements in lichen and mussel samples for comparison purposes.

Ultrasound-assisted extraction was studied as sample preparation method for inductively coupled plasma optical emission spectrometry (ICP-OES) analysis of eight metals (Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn) in sewage sludge. Microwave digestion was used for comparison. A multivariate approach (experimental design) was used for the optimization of both sample preparation methods. Microwave digestion was completely optimized by means of 2 (5-1) fractional factorial design. The optimum microwave digestion conditions were 120 psi pressure, 30 min time-at-pressure, 3 ml HNO 3 , 1 ml HF and 1 ml HCl. The utility of a new ultrasound probe system equipped with an all-glass sonotrode, which lowers the possibility of sample contamination, was evaluated for the first time. Ultrasound extraction was optimized by applying three different experimental designs. The optimum conditions were found to be 80% amplitude of the ultrasound energy (400 W), 20 min sonication time, 90 °C temperature, mixture of 5 ml HNO 3 and 5 ml of HCl, bubbling and 10 min magnetic stirring. Both optimized sample pretreatment methods were validated with the BCR reference material no. 146R (sewage sludge of industrial origin) and three real sewage sludge samples, yielding microwave digestion quantitative recoveries for all the elements studied, whereas ultrasound energy quantitatively extracts only Cd, Cu, Pb and Zn. With ultrasounds, recovery values higher than 75, 84 and 81% were obtained for Cr, Mn and Ni, respectively, and Co was not able to be detected. Reproducibility and overall analysis time were similar for ultrasound and microwave extractions. Hence, with some limitations that mainly came from the available technology, the ultrasound extraction procedure was found to be a good alternative to the common microwave digestion since the former is less hazardous (i.e., it works under atmospheric pressure and does not use HF acid) and it is considerably cheaper than the microwave system.

The purpose of this paper is to validate the microwave digestion method with a HNO3/H2O2 mixture for determination of 18 trace elements (Li, Be, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Cd, Cs, Ba, and Pb) in coal by inductively coupled plasma optical emission spectrometry and inductively coupled plasma mass spectrometry. The digestion with a HNO3/H2O2/minute HF mixture was conducted for comparison, and the results were evaluated with reference to three standard coals (SRM1632c, BCR180, and SARM19). It was found that the addition of HF was not required to extract quantitatively the above trace elements in all three coals with the exception of Rb in SARM19 coal by elevating the digestion temperature to 220 °C and pressure to 2 MPa. Through this rigorous digestion, the organic matrices and clay minerals in coal were extensively decomposed even without HF. However, some trace elements such as V, Cr, Ni, Ga, Sr, and Ba in SARM19 coal were not quantitatively extracted under a milder condition (180 °C and 0.9 MPa), probably because these trace elements partially remained in the organic matrix and clay residues.

A novel method for inductively coupled plasma atomic emission spectrometry (ICP-AES) determination of trace amounts of Pt(II), Pd(II) and Rh(III), based on gaseous compounds introduction into the plasma as their diethyldithiocarbamate complexes by electrothermal vaporization (ETV), was developed. At the temperature of 1100 °C, the trace amounts of Pt, Pd and Rh were vaporized into plasma. The factors affecting the formation of the chelates and their vaporization behaviors, such as ashing temperature and time, vaporization temperature and time, pH and the concentration of chelating reagents were studied in detail. Under the optimized conditions, the limits of detection (LODs) (3σ) of Pt, Pd and Rh for tested solutions were 5.4, 1.4 and 0.8 ng ml−1, and for actual sample (auto-catalyst NIST SRM 2557) were 0.27, 0.07 and 0.04 μg g−1, respectively. The relative standard deviations (RSDs) for Pt, Pd and Rh were 1.4, 2.6 and 2.4% (CPt=0.5 μg ml−1, CPd,Rh=0.25 μg ml−1, n=7), respectively. The linear ranges of calibration graphs for Pt, Pd and Rh cover three orders of magnitude. Compared with conventional electrothermal vaporization technique, using the reagent of diethyldithiocarbamate as chemical modifier could not only enhance the analytical sensitivities, but also reduce the vaporization temperature. By combination with a separation/preconcentration step, the proposed method had been successfully applied to the analysis of the artificial seawater, tap water and urine with recoveries ranging from 91 to 106%. The two certified reference material meager platinpalladium ore GBW 07293 and auto-catalyst NIST SRM 2557 was also analyzed for validation, and the determined values obtained were in good agreement with the certified values.

The possibility of electrochemical oxidation of Pb2+ to PbO2 as a method of isolation of lead in low concentrations in copper and silver matrixes was studied. Suitable electrolysis cell was developed and the influence of various factors (electrode surface and state, reaction time, temperature, electrolyte volume, acidity, concentration of indifferent electrolyte, stirring rate and current density) on the efficiency of the process was evaluated. The accuracy and reproducibility of the method were estimated by determination of the quantity of lead in SRMs by inductively coupled plasma atomic emission spectrometry (ICP-AES) and atomic absorption spectroscopy (AAS). By means of ICP-mass spectrometry (MS), the lead isotopic ratios in SRMs were determined.

In this study, 13 ceramic samples were subjected to dissolution using three different procedures: (a) acid attack in open PTFE vessels with a mixture of HF–HClO 4 , (b) fusion of the sample with lithium metaborate and (c) microwave digestion in PTFE bombs. The samples used in the study had been previously analyzed by neutron activation analysis (NAA), X-ray fluorescence (XRF) and X-ray diffraction (XRD) and they cover a wide range of ceramics fired in different atmospheres and temperatures as well as different mineralogical and chemical compositions. The effectiveness of each procedure is evaluated in terms of its ability to dissolve the various mineralogical phases of the samples, of the number of elements that can be determined and of the time needed for the whole scheme of analysis to be completed.

An ion-exchange procedure is proposed for determination of Pt and Pd in environmental samples, using a Dowex 1-X10 anion-exchange resin. Pt and Pd were separated from the matrix elements in the sample by selective retention on the column as anionic chloro complexes and subsequent elution by circulated thiourea at 60 °C. The eluent, containing Pt and Pd was analyzed by inductively coupled plasma (ICP) atomic emission spectrometry (AES). Average recoveries of 98% and detection limit of 15 ng/g for both metals were achieved. Analysis of Pt and Pd concentrations in road dust, sampled from several sites in Germany was performed. The comparison of the obtained data with the concentrations of Pt and Pd in the same samples, determined by ICP-MS showed a very good agreement.

A method was investigated for the determination of Sn in soil samples by KOH fusion followed by continuous hydride generation coupled with inductively coupled plasma mass spectrometry (HG-ICP-MS). Sample solutions in 3.0 M HCl were mixed in line with a solution of 2.4% NaBH 4 and 0.25 M KOH to generate stannane gas. The mixture was delivered continuously to a gas/liquid separator and the stannane gas was introduced into a Perkin-Elmer Sciex Elan 6000 ICP-MS for concentration measurements. A method detection limit of 0.45 mg/kg was sufficient for Sn levels commonly found in soil samples. Sn concentrations as low as 2.5 mg/kg were reproducibly measured in soil samples. Sample results by HG-ICP-MS agreed within ±17% relative difference to results by instrumental neutron activation analysis (INAA) and within ±6% relative difference to results by KOH fusion followed by inductively coupled plasma optical emission spectroscopy (ICP-OES).

Chemical characterization of Italian red wines from different geographical locations in the Apulia, region of southern Italy, have been performed by means of chromatographic, analyses routine analyses (density, alcohol content, acidity, dry extract and ash content), inductively coupled plasma-atomic emission spectrometric measurements and nuclear magnetic resonance ( 1 H NMR) spectrometric determinations. Multivariate statistical methods were applied separately to the analytical and NMR data. The results showed that Apulian red wines are divided in three groups according to their geographical origin.

A flow system for on-line pre-concentration of Cd, Ni and Pb and determination by inductively coupled plasma atomic emission spectrometry is presented. The manifold comprised a set of three-way solenoid valves, which were controlled by a microcomputer running software written in Quick Basic 4.5 by means of an A/D board. Since the flow network was based on the multicommutation concept pre-concentration and elution steps could be simultaneously performed in several columns in parallel with significant analytical throughput improvement. Comparing obtained results with certified values, no significant difference at 95% confidence level was observed. Other valuable features such as an analytical throughput of 90 determinations per hour, relative standard deviation

The present work evaluates the influence of vessel cooling simultaneously to microwave-assisted digestion performed in a closed system with diluted HNO 3 under O 2 pressure. The effect of outside air flow-rates (60–190 m 3 h −1 ) used for cooling of digestion vessels was evaluated. An improvement in digestion efficiency caused by the reduction of HNO 3 partial pressure was observed when using higher air flow-rate (190 m 3 h −1 ), decreasing the residual carbon content for whole milk powder from 21.7 to 9.3% (lowest and highest air flow-rate, respectively). The use of high air flow-rate outside the digestion vessel resulted in a higher temperature gradient between liquid and gas phases inside the digestion vessel and improved the efficiency of sample digestion. Since a more pronounced temperature gradient was obtained, it contributed for increasing the condensation rate and thus allowed a reduction in the HNO 3 partial pressure of the digestion vessel, which improved the regeneration of HNO 3 . An air flow-rate of 190 m 3 h −1 was selected for digestion of animal fat, bovine liver, ground soybean, non fat milk powder, oregano leaves, potato starch and whole milk powder samples, and a standard reference material of apple leaves (NIST 1515), bovine liver (NIST 1577) and whole milk powder (NIST 8435) for further metals determination by inductively coupled plasma atomic emission spectroscopy (ICP-OES). Results were in agreement with certified values and no interferences caused by matrix effects during the determination step were observed.

In routine analysis by inductively coupled plasma–optical emission spectrometry (ICP–OES), non-spectral interferences, which are classified into physical, chemical, ionization and excitation interferences, should be taken into consideration to obtain a more accurate analytical result. The excitation interference is principally due to a variation in the number of excited atoms resulted from a change in the excitation temperature of an ICP. It could be caused by variations not only in the discharge parameters, such as an radio frequency (rf) forward power but in physical parameters, such as the kind and concentration of acids in the sample solution. By using vanadium test solutions prepared at various acid concentrations, the excitation temperature was estimated from the Boltzmann plots. The excitation temperatures were slightly elevated with an increase in the acid concentration ranging from 0 to 50 ml in a 100 ml solution: increases of 33 and 16 K in a sulfuric acid system and a nitric acid–hydrochloric acid system, respectively were observed. The intensity ratios between vanadium ionic lines having almost the same excitation energy, and the intensity ratios having different excitation energies were also measured.

A new method using a microcolumn packed with nanometer TiO 2 as solid-phase extractant has been developed for the simultaneous preconcentration of trace amounts of Cu, Mn, Cr and Ni prior to their measurements by inductively coupled plasma atomic emission spectrometry (ICP-AES). Effects of pH, sample flow rate and volume, elution solution and interfering ions on the recovery of the analytes have been investigated. The adsorption capacity of nanometer TiO 2 was found as 0.108, 0.149, 0.039 and 0.034 mmol g −1 for Cu, Cr, Mn and Ni, respectively. The separation of analytes can be achieved from water samples with a concentration factor of 50 times. The method has been applied for the determination of trace elements in biological sample and lake water with satisfactory results.

A new method for determination of trace beryllium by electrothermal vaporization (ETV)-inductively coupled plasma atomic emission spectrometry (ICP-AES) with the use of acetylacetone as chemical modifier is developed. Trace beryllium was vaporized as acetylacetonate into plasma at a low-temperature of 700°C, and the vaporization behavior of acetylacetonate of beryllium was investigated in detail. Under the optimized conditions, beryllium acetylacetonate could be quantitatively vaporized. The detection limit of beryllium was 0.2 ng ml −1 , compared with the conventional pneumatic nebulization ICP-AES, the detection limit could be improved by 45-fold. The relative standard deviations for 0.01 μg ml −1 of Be was 4.1%. The linear range of the calibration curve covered three orders of magnitude. The proposed method was applied to the determination of trace beryllium in human hair standard reference material and the results obtained were in good agreement with the reference values.