Coupled Plasma Microtorch Optical Emission Research Articles

Simultaneous determination of Cd, Pb, Cu and Zn as total and labile fractions in soil using a small-sized electrothermal vaporization capacitively coupled plasma microtorch optical emission spectrometer after diffusive gradients in thin-film passive accumulation

A sensitive and free interference method for the determination of total and labile fractions of Cd, Pb, Cu and Zn in soil after DGT passive accumulation and detection by optical emission spectrometry with an Ar microplasma was validated.

In-situ Diffusive Gradients in thin-films passive sampling coupled with ex-situ small-sized electrothermal vaporization capacitively coupled plasma microtorch optical emission spectrometry as green and white method for the simultaneous determination of labile species of toxic elements in surface water

This study presents for the first time the coupling between in-situ Diffusive Gradient in Thin-film (DGT) passive sampling technique and ex-situ small-sized instrumentation based on electrothermal vaporization capacitively coupled plasma microtorch optical emission spectrometry (SSETV-μCCP-OES) for the simultaneous determination of Cd, Pb, Cu, Zn and Hg in surface water. Unique features of the DGT-SSETV-μCCP-OES are low power and low Ar consumption for plasma generation (15 W, 150 mL min−1) and significant improvement of the detection limits following DGT passive sampling. The new method was validated in terms of river water analysis in comparison with graphite furnace atomic absorption spectrometry and thermal decomposition atomic absorption spectrometry. Combining the abilities of preconcentration by in-situ Chelex-DGT passive sampling with plasma microtorch equipped with a low resolution microspectrometer provided multielemental simultaneous determination with detection limits of (μg L−1) 0.01 (Cd, Zn and Hg), 0.02 (Cu) and 0.07 (Pb) in water, at least one order of magnitude better than using grab sampling without preconcentration. It was possible the quantification of labile fraction of priority hazardous metals (Cd, Pb) in river water below the instrumental limits of detection (μg L−1) of 0.12 and 0.80 obtained in SSETV-μCCP-OES without DGT sampling. The precision of the method was in the range 15.3–22.4% (combined uncertainty), while the accuracy was 95–103% and trueness of 27–33% (expanded uncertainty, k = 2). The DGT-SSETV-μCCP-OES coupling proved to be an ideal and powerful tool for surface water analysis in compliance with green and white analytical chemistry concepts. The application of the RGB-12 algorithm provided very good red/green (AGREEprep)/blue/white scores (%) of 100/80/98/93, determined primarily by in-situ DGT passive sampling, very good detection limits and cost-effective SSETV-μCCP-OES instrumentation.

Greenness and whiteness profiles of Uv/vis photochemical vapor generation capacitively coupled plasma microtorch optical emission spectrometry method for mercury determination and speciation in food and water

Greenness and whiteness profiles of Uv/vis photochemical vapor generation capacitively coupled plasma microtorch optical emission spectrometry method for mercury determination and speciation in food and water

Simultaneous Determination of As, Bi, Sb, Se, Te, Hg, Pb and Sn by Small-Sized Electrothermal Vaporization Capacitively Coupled Plasma Microtorch Optical Emission Spectrometry Using Direct Liquid Microsampling.

The simultaneous determination of chemical vapor-generating elements involving derivatization is difficult even by inductively coupled plasma optical emission spectrometry or mass spectrometry. This study proposes a new direct liquid microsampling method for the simultaneous determination of As, Bi, Se, Te, Hg, Pb, and Sn, using a fully miniaturized set-up based on electrothermal vaporization capacitively coupled plasma microtorch optical emission spectrometry. The method is cost-effective, free from non-spectral interference, and easy to run by avoiding derivatization. The method involves the vaporization of analytes from the 10 µL sample and recording of episodic spectra generated in low-power (15 W) and low-Ar consumption (150 mL min−1) plasma microtorch interfaced with low-resolution microspectrometers. Selective vaporization at 1300 °C ensured the avoidance of non-spectral effects and allowed the use of external calibration. Several spectral lines for each element even in the range 180–210 nm could be selected. Generally, this spectral range is examined with large-scale instrumentation. Even in the absence of derivatization, the obtained detection limits were low (0.02–0.75 mg kg−1) and allowed analysis of environmental samples, such as cave and river sediments. The recovery was in the range of 86–116%, and the accuracy was better than 10%. The method is of general interest and could be implemented on any miniaturized or classical laboratory spectrometric instrumentation.

Interference-free, green microanalytical method for total mercury and methylmercury determination in biological and environmental samples using small-sized electrothermal vaporization capacitively coupled plasma microtorch optical emission spectrometry

An analytical method for the quantification of total Hg and CH3Hg+ in biological tissues (fish, mushroom) and water sediment was developed based on small-sized electrothermal vaporization capacitively coupled plasma microtorch optical emission spectrometry using a low-resolution microspectrometer as detector. Sample preparation was carried out according to the procedure recommended by JRC Technical Report of European Commission for the determination of CH3Hg+ in seafood and adapted by us for lower consumption of reagents. Amounts of 0.1 – 0.5 g sample were subjected to extraction in 5 ml of 47% HBr then CH3Hg+ was extracted in 2 × 1 ml toluene and back-extracted in 2 ml aqueous solution of 1% l-cysteine. Total Hg/CH3Hg+ were quantified in 10 μl of acidic extract/l-cysteine solution after electrothermal vaporization and measurement of 253.652 nm Hg signal in the episodic emission spectra. Under the optimal working conditions of system (70 °C sample drying, 1300 °C sample vaporization, 10 W plasma power and 150 ml min−1 Ar flow) the limits of detection were 7.0 μg kg−1 total Hg and 3.5 μg kg−1 CH3Hg+. Comparison of slopes in external calibration and standard addition procedure revealed the lack of non-spectral interferences of multimineral matrix, so that the calibration against Hg2+ standards was adopted. Pooled recovery of total mercury/methylmercury was 101 ± 7%/100 ± 7%, while precision assessed from measurements of real samples was in the range 1.6-9.6%/2.7-12.8%. The proposed method validated according to Eurachem Guide 2014 is selective and complies with demands in European legislation (Decisions 657/2002; 333/2007; 836/2011) and Association of Official Analytical Chemists Guide in terms of performances for food control. The method displays a high degree of greenness by circumventing cold vapor generation, use of small amounts of reagents and full-miniaturized instrumentation resulting in low analytical costs without reducing results quality. Besides, the method is simple and rapid, since it uses external calibration curves prepared from Hg2+standard solutions both for total Hg and CH3Hg+ determination.

Eco-scale non-chromatographic method for mercury speciation in fish using formic acid extraction and UV–Vis photochemical vapor generation capacitively coupled plasma microtorch optical emission spectrometry

An eco-scale method based on UV–Vis photochemical vapor generation and detection in a capacitively coupled plasma microtorch by optical emission measurement with a low resolution microspectrometer was developed for Hg speciation as Hg2+ and CH3Hg+ in seafood. Our proposal provides a simpler, greener analytical method in terms of sample preparation and derivatization, and use of small-scale instrumentation. Coupling of UV–Vis photo-reactor with plasma microtorch is a very promising approach to develop eco-scale methods for Hg speciation in seafood with major advantages to classical methods. The most distinctive characteristic of the method is the use of a single reagent, formic acid, for the extraction of Hg species from solid sample and as medium for the photo-induced cold vapor generation. An amount of 0.2 g lyophilized sample was subjected to ultrasound assisted extraction in 10 ml HCOOH 98–100% at 50 °C for 3 h then on line UV–Vis photo-induced derivatization in 0.6 mol l−1 HCOOH was achieved. Total Hg and Hg2+ species were quantified against Hg2+ external standard solutions by measuring emission at 253.652 nm in a low power/low Ar consumption (15 W/100 ml min−1) plasma source with Maya2000 Pro (Ocean Optics) microspectrometer. Under UV exposure both Hg2+ and CH3Hg+ species were converted with same efficiency to cold vapor, while natural room light (Vis) achieved selectively derivatization of Hg2+. Concentration of CH3Hg+ was obtained by subtracting Hg2+ amount from total. The proposed method was compared with Thermal Decomposition Atomic Absorption Spectrometry eco-scale method developed for the determination of total Hg from solid sample and CH3Hg+ according to the procedure recommended by the European Commission. The limits of detection/quantification provided by the proposed method were 9/27 μg kg−1 total Hg and 4.8/14.4 μg kg−1 Hg2+. Study of accuracy against certified reference materials gave recovery of 99 ± 6% total Hg, 99 ± 9% Hg2+ and 99 ± 10% CH3Hg+, while precisions assessed from measurements on real sample were 2.6–10.2%, 2.0–13.4% and 5.3–14.5% respectively, similar to those in the reference method.

A highly sensitive eco-scale method for mercury determination in water and food using photochemical vapor generation and miniaturized instrumentation for capacitively coupled plasma microtorch optical emission spectrometry

A sensitive method with a green profile for Hg determination in food and water was developed.

Mercury speciation in seafood using non-chromatographic chemical vapor generation capacitively coupled plasma microtorch optical emission spectrometry method – Evaluation of methylmercury exposure

A non-chromatographic method was developed for Hg speciation as CH3Hg+ and Hg2+ using simple instrumentation based on optical emission spectrometry in a low power and low Ar consumption capacitively coupled plasma microtorch and detection with a low resolution microspectrometer. The method is based on (i) determination of total Hg after sample digestion in nitric acid-hydrogen peroxide mixture, derivatization to cold vapor with 20% SnCl2 in 15% HCl medium; (ii) determination of CH3Hg+ separated by double liquid-liquid extraction as recommended in JRC Technical Report of European Commission, followed by photochemical vapor generation in 0.6 mol l−1 formic acid and (iii) calculation of the inorganic (Hg2+) species as difference. The calibration curve was generated with external Hg2+ standards in 5% (v/v) HCl for total Hg determination and 0.6 mol l−1 HCOOH medium for CH3Hg+, respectively. The method was validated against certified reference materials and successfully applied for Hg speciation in most consumed fish species. The limits of detection of the method were 2 and 3 μg kg−1 CH3Hg+ and total Hg respectively, which made possible quantification of 6/9 μg kg−1 organic/total Hg. The method proved to be accurate with recovery of 101 ± 10% (total Hg), 100 ± 8% (CH3Hg+) and 102 ± 13% (Hg2+), and precision in the range 2.4–7.8% (total Hg), 2.4–11.9% (CH3Hg+) and 3.8–14.0% (Hg2+). The speciation method allowed accurate and precise determination of CH3Hg+ and Hg2+ even when the organic species represented more than 98% of total Hg. Total Hg in fish depended on variety but in all cases it was below the maximum admitted level (0.5 mg kg−1). Methylmercury represented 22.3–93.3% of total Hg, with higher weights in salmon, carp, mackerel and hake and lower in cod, trout and pangasius irrespective of total Hg. Evaluation of risk exposure to CH3Hg+ from occasional fish consumption based on Provisional Tolerable Weekly Intake seems to be much more informative than the concentration of total or organic Hg species. It has been concluded from our study that there is no health risk from exposure to methylmercury for 300–1000/60-200 g weekly fish consumption by adult/child when fish comes from reliable sources.

Methylmercury determination in seafood by photochemical vapor generation capacitively coupled plasma microtorch optical emission spectrometry

A non-chromatographic method based on double liquid-liquid extraction and measurements by UV photochemical vapor generation capacitively coupled plasma microtorch optical emission spectrometry was developed and characterized for methylmercury determination in seafood. Samples were prepared following the procedure recommended in JRC Technical Report of European Commission formerly proposed for the determination of methylmercury in seafood by thermal decomposition atomic absorption spectrometry, namely confinement of Hg species in 47% HBr solution, extraction of CH3Hg+ in toluene and back-extraction in 1% l-cysteine aqueous solution. Mercury cold vapor was generated by flow injection UV photo-reduction from CH3Hg+ in 0.6molL−1 HCOOH, while quantification was performed against external Hg2+ aqueous standards and measuring Hg 253.652nm emission using a low power/Ar consumption plasma microtorch (15W, 100mLmin−1) and a low resolution microspectrometer (Ocean Optics). The figures of merit and analytical capability were assessed by analyzing certified reference materials and test samples of fish fillet and discussed in relation with requirements for Hg determination in seafood in European legislation (Decisions 2007/333/EC and 2002/657/EC) as well as compared to performances achieved in thermal decomposition atomic absorption spectrometry. The limit of detection and quantification of 2µgkg−1 and 6µgkg−1 respectively, precision of 2.7–9.4% and accuracy of 99±8% of the proposed method for the determination of CH3Hg+ fulfill the demands of European legislation for Hg quantification. The limit of detection and quantification were better than those in the used reference method or other non-/chromatographic methods taken for comparison. The analysis of certified reference materials and the Bland and Altman test performed on 12 test samples confirmed trueness of the proposed method and its reliability for the determination of traces of CH3Hg+ with 95% confidence level. The proposed method fulfills several demands of the eco-scale concept, is sensitive, simple and safe related to sample preparation through elimination of classical, harmful reductants and attractive by using economical miniaturized instrumentation incorporating a low power and low Ar consumption plasma.

A microanalytical method based on electrothermal vaporization capacitively coupled plasma microtorch optical emission spectrometry for multielemental determination: comparison with inductively coupled plasma optical emission spectrometry

A microanalytical method based on small-sized electrothermal vaporization low power (15 W) and low Ar consumption (150 mL min−1) capacitively coupled Ar plasma microtorch and detection by optical emission spectrometry using a low-resolution microspectrometer was characterized for determination of As, Ag, Cd, Cu, Hg, Pb, Sb, Sn and Zn. Elements requiring usually either hydride (As, Sb, Sn) or cold vapor generation (Hg) were determined along with other elements using the completely miniaturized analytical system. A volume of 10 µL sample was vaporized on a Rh coil (1500 °C, 10 s), introduced into the plasma with the Ar flow followed by recording of 20 spectra episodes using the QE65 Pro microspectrometer. The emission spectrum of elements is simple, so that the coupling microtorch-microspectrometer with 0.4 nm full-width half maximum was adequate. The detection limits were in the range 1.5–40 ng mL−1, similar or better compared to those found in the reference method, inductively coupled plasma optical emission spectrometry. The new method complies with the requirements for environmental analyses and has been applied to determine elements in soil and sediment samples using the standard addition method with recovery and precision in the range 92–104% and 0.4–11.6%, respectively. The miniaturized instrumentation including the plasma microtorch is a promising alternative to inductively coupled plasma optical emission spectrometry with pneumatical nebulization.

Determination of Cd in food using an electrothermal vaporization capacitively coupled plasma microtorch optical emission microspectrometer: Compliance with European legislation and comparison with graphite furnace atomic absorption spectrometry

A precise, accurate and sensitive method based on electrothermal vaporization capacitively coupled plasma microtorch optical emission spectrometry for Cd determination in various dietary products was developed. The instrumentation is inexpensive as it includes a low power (15 W) and low argon consumption (150 ml min−1) microplasma connected to a small-sized Rh electrothermal vaporization device and a low resolution microspectrometer. The sample was subjected to microwave assisted digestion in HNO3 – H2O2 mixture and Cd was determined in 10 μl sample without preconcentration. The standard addition method was used to compensate for the non-spectral matrix effects. The new method was in-house validated by analyzing certified reference materials and test dietary samples for which the Cd maximum level was established in Commission Regulation 488/2014/EU. The figures of merit of the proposed method and the experimental results were compared to those obtained in graphite furnace atomic absorption spectrometry as standardized method and discussed in relation with the requirements in the Commission Decision 2002/657/EC and Commission Regulations 2011/836/EU and 2007/333/EC. The limit of detection in fresh sample (0.001–0.009 mg kg−1), limit of quantification (0.002–0.018 mg kg−1), recovery (103 ± 15%), trueness (−3.0)–(+7.3)% and precision (0.8–14.0%) were similar to those found in the reference method and comply with the minimal criteria imposed to a method to be used in official laboratories for Cd determination in food. Precision for Cd determination close to maximum admitted levels or higher was of 0.8–6.0%, while for lower concentration in the range 4.0–14.0%. The Bland and Altman statistical test allowed successful evaluation of the new method as an alternative to the well established graphite-furnace atomic absorption spectrometry. The proposed method has analytical potential and is easy to run, while the full miniaturized instrumentation could be considered as a useful tool for the future as an alternative to the traditional instrumentation.

Application of low-cost electrothermal vaporization capacitively coupled plasma microtorch optical emission spectrometry for simultaneous determination of Cd and Pb in environmental samples

The study discusses the applicability and analytical capability of a laboratory miniaturized system including a small-sized electrothermal vaporizer with Rh filament and a low power (15W) and low Ar consumption (150mlmin−1) capacitively coupled plasma microtorch interfaced with a low resolution microspectrometer for the simultaneous determination of Cd and Pb in environmental samples by optical emission spectrometry. Ten-microliter samples were dried (100°C, 80s) and vaporized (1500°C, 6s) by filament heating, then sample vapor was introduced into plasma via an Ar stream and 20 successive emission episodes were recorded with 500ms integration time per episode. The operating parameters of the electrothermal vaporization device and plasma were optimized in order to achieve the simultaneous determination of the two elements with best analytical performance. The method was verified by analyzing CRMs of soil, and then applied to real samples digested in aqua regia. The standard addition method was used to compensate for the non-spectral matrix effects on the analytical signal. Under the optimized conditions the limits of detection were 130±35μgkg−1 (13pg) for Cd at 228.802nm and 2100±175μgkg−1 (210pg) for Pb at 368.346nm. Recovery was in the range 98±18% for Cd and 103±11% for Pb for 95% confidence interval, while the relative standard deviation of repeatability was 4–12% (n=3). The investigated instrumentation has analytical potential and prototyping perspective to be used for toxic element determination in environmental samples.

Analytical characterization of a method for mercury determination in food using cold vapour capacitively coupled plasma microtorch optical emission spectrometry – compliance with European legislation requirements

This paper presents the analytical characterization of a highly sensitive and inexpensive method for Hg determination.

Sono-induced cold vapour generation interfaced with capacitively coupled plasma microtorch optical emission spectrometry: analytical characterization and comparison with atomic fluorescence spectrometry

Sono-induced cold vapour generation was interfaced for the first time with a plasma microtorch for Hg determination.

Determination of Total Mercury in Fish Tissue Using a Low-Cost Cold Vapor Capacitively Coupled Plasma Microtorch Optical Emission Microspectrometer: Comparison with Direct Mercury Determination by Thermal Decomposition Atomic Absorption Spectrometry

A method for total Hg determination in fish tissue using cold vapor capacitively coupled plasma microtorch optical emission spectrometry was evaluated. The low-cost miniaturized analytical system includes a low power plasma microtorch (10 W) and low Ar consumption (150 ml min−1) and a QE65Pro microspectrometer as detector. Lyophilized fish tissues were microwave-assisted digested in HNO3–H2O2 mixture, brought in 5 % (v/v) HCl, then Hg vapor was chemically generated with 20 % SnCl2 solution stabilized in 15 % (v/v) HCl. The figures of merit of the proposed method were evaluated by analyzing certified reference materials and test samples and compared to those of the well-established thermal decomposition atomic absorption spectrometry method. The analytical characteristics (limits of detection and quantification, precision, and accuracy) comply with requirements for Hg determination in seafood set out in Decisions 2007/333/EC and 2002/657/EC. The limits of detection and quantification of the proposed method were 3 and 9 μg kg−1 Hg in dry mass, similar to those in thermal decomposition atomic absorption spectrometry. The precision was between 1.8 and 5.5 % for concentrations in the range 0.18–0.76 mg kg−1 Hg, while the accuracy was 99.7 ± 3.0 %. The significance tests revealed no difference between the results obtained by the two methods. The proposed miniaturized spectrometric equipment could be the subject of prototyping as low-cost instrumentation for designed applications in seafood control.

Simultaneous determination of As and Sb in soil using hydride generation capacitively coupled plasma microtorch optical emission spectrometry – comparison with inductively coupled plasma optical emission spectrometry

A method using a miniature analytical system based on hydride generation capacitively coupled plasma microtorch optical emission spectrometry with a QE65 Pro microspectrometer was developed and evaluated for the simultaneous determination of As and Sb in soil samples. The use of this microspectrometer allows the examination of the spectral range between 190 and 220 nm where the continuum background emission of the plasma is low and the most intense resonance lines As 193.759; 197.262 nm and Sb 206.833; 217.581 nm are located. The method involves microwave-assisted digestion of samples in aqua regia, prereduction of As(V) and Sb(V) to their (+3) species with 0.3% L-cysteine by heating in a boiling water bath at 90 ± 5 °C and hydride generation in 0.01 mol L−1 HCl (pH = 2.00 ± 0.01) medium with 0.5% NaBH4 solution. The method was optimized in order to provide the simultaneous determination of As and Sb. The figures of merit were evaluated at different emission wavelengths under the optimum conditions of plasma microtorch operation (10 W, 150 mL min−1 Ar), and the best performances were obtained at 193.759 nm (As) and 217.581 nm (Sb). The figures of merit of the method were compared to those of the traditional hydride generation inductively coupled plasma optical emission spectrometry taken as a reference method. Analysis of CRMs revealed recoveries of 101 ± 9% As and 102 ± 3% Sb comparable to 102 ± 7% As and 98 ± 4% Sb in the reference method. The precision of determinations was 2–10% for 90–210 mg kg−1 As and 40–130 mg kg−1 Sb, close to 3–8% in hydride generation inductively coupled plasma optical emission spectrometry. The Bland and Altman test performed on 10 soil samples indicated no significant difference between the results obtained by the two methods, so that the miniature analytical system could be successfully applied for As and Sb monitoring in environmental samples. The proposed method is attractive in terms of analytical costs due to limited consumption of high purity HCl, power and Ar to sustain the plasma, and therefore more advantageous than hydride generation inductively coupled plasma optical emission spectrometry.

A miniaturized capacitively coupled plasma microtorch optical emission spectrometer and a Rh coiled-filament as small-sized electrothermal vaporization device for simultaneous determination of volatile elements from liquid microsamples: Spectral and analytical characterization

A low power and low argon consumption (13.56MHz, 15W, 150mlmin−1) capacitively coupled plasma microtorch interfaced with a low-resolution microspectrometer and a small-sized electrothermal vaporization Rh coiled-filament as liquid microsample introduction device into the plasma was investigated for the simultaneous determination of several volatile elements of interest for environment. Constructive details, spectral and analytical characteristics, and optimum operating conditions of the laboratory equipment for the simultaneous determination of Ag, Cd, Cu, Pb and Zn requiring low vaporization power are provided. The method involves drying of 10μl sample at 100°C, vaporization at 1500°C and emission measurement by capture of 20 successive spectral episodes each at an integration time of 500ms. Experiments showed that emission of elements and plasma background were disturbed by the presence of complex matrix and hot Ar flow transporting the microsample into plasma. The emission spectrum of elements is simple, dominated by the resonance lines. The analytical system provided detection limits in the ngml−1 range: 0.5(Ag); 1.5(Cd); 5.6(Cu); 20(Pb) and 3(Zn) and absolute detection limits of the order of pg: 5(Ag); 15(Cd); 56(Cu); 200(Pb) and 30(Zn). It was demonstrated the utility and capability of the miniaturized analytical system in the simultaneous determination of elements in soil and water sediment using the standard addition method to compensate for the non-spectral effects of alkali and earth alkaline elements. The analysis of eight certified reference materials exhibited reliable results with recovery in the range of 95–108% and precision of 0.5–9.0% for the five examined elements. The proposed miniaturized analytical system is attractive due to the simple construction of the electrothermal vaporization device and microtorch, low costs associated to plasma generation, high analytical sensitivity and easy-to-run for simultaneous multielemental analysis of liquid microsamples.

New method for mercury determination in microwave digested soil samples based on cold vapor capacitively coupled plasma microtorch optical emission spectrometry: Comparison with atomic fluorescence spectrometry

Abstract A new sensitive method for total mercury determination in digested soils using a miniaturized analytical system based on cold vapor capacitively coupled plasma microtorch optical emission spectrometry was developed and compared with cold vapor atomic fluorescence spectrometry as the standardized method. The soil samples were subjected to microwave digestion in aqua regia, than Hg cold vapor were chemically generated with SnCl2 and introduced via a 150 ml min− 1 Ar flow rate in the plasma microtorch operated at 10 W power level. The optical emission signal at 253.652 nm was measured with a commercially available microspectrometer. The method detection limit was 4.8 μg kg− 1 Hg, similar to that obtained in the standardized reference method. The precision of Hg determination over the concentration range of 0.27–55 mg kg− 1 was 0.8–7.7%. Analysis of six CRMs revealed a recovery of 97 ± 7% similar to 97 ± 9% found in the method based on cold vapor atomic fluorescence spectrometry. The Bland and Altman test carried out on 31 test soil samples showed no significant statistical difference between the results obtained by the proposed method and that taken as reference. The investigated analytical system can be prototyped as an alternative for the commercially existing atomic fluorescence spectrometry instrumentation. The benefits of the system are related to small size instrumentation and low analysis cost due to the low power and low Ar consumption for plasma generation.

Arsenic and antimony determination in non- and biodegradable materials by hydride generation capacitively coupled plasma microtorch optical emission spectrometry

A sensitive method using a miniature analytical system with a capacitively coupled plasma microtorch (25W, 13.56MHz, 0.4lmin−1 Ar) was developed and evaluated for the determination of As and Sb in recyclable plastics and biodegradable materials by hydride generation optical emission spectrometry. Given their toxicity, As and Sb should be subject to monitoring in such materials despite not being included within the scope of Restriction of Hazardous Substances Directive. The advantages of the proposed approach are better detection limits and lower analysis cost relative to conventional systems based on inductively coupled plasma optical emission and flame atomic absorption spectrometry with/without derivatization. Samples were subjected to acidic microwave-assisted digestion in a nitric–sulfuric acid mixture. Chemical hydride generation with 0.5% NaBH4 after the prereduction of As(V) and Sb(V) with 0.3% l-cysteine in 0.01moll−1 HCl (10min contact time at 90±5°C) was used. Under the optimal hydride generation conditions and analytical system operation the detection limits (mgkg−1) were 0.5 (As) and 0.1 (Sb), whereas the precision was 0.4–7.1% for 10.2–46.2mgkg−1 As and 0.4–3.2% for 7.1–156mgkg−1 Sb. Analysis of two polyethylene CRMs revealed recoveries of 101±2% As and 100±1% Sb.