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Although Kevin determined the fish arsenic in a crustacean (Western Rock Lobster), arsenobetaine was later established as the main organoarsenic compound in fish and shellfish. Both papers make arsenic speciation analysis more transparent and democratic, and enhance the proficiency of arsenic species determination, absolutely in line with Kevin's passion for only the best analytical chemistry. A whole generation of environmental analytical chemists interested in arsenic speciation relied (and still relies) on Kevin's talented hands (yes, Kevin was still active in the lab himself) to produce some complex organoarsenicals as standards, which were either isolated from marine organisms or synthesised (e.g. [11]). I am honoured to have been asked to organise a special issue for Professor Kevin A. Francesconi, a towering figure in environmental chemistry, who retired a few years ago from his leading role as Professor for Analytical Chemistry at the University of Graz in Austria. [Extracted from the article]

Environmental context: The marine ecosystem is highly elevated in arsenic in comparison to the terrestrial environment. More than 100 different naturally occurring organoarsenic compounds have been found in different marine organisms. In order to understand how highly toxic AsHCs are formed and bioaccumulate in different marine organisms, large scale monitoring of AsHCs from a range of different laboratories is necessary. Despite their toxicity, AsHCs have not been extensively studied due in part to the lack of low-cost analytical methods and the lack of commercially available standards. Rational: This study aims to develop a new analytical method for the quantitative determination of arsenic-containing hydrocarbons (AsHCs) with gas chromatography–mass spectrometry (GC-MS). The new method is an alternative approach to determine these compounds in environmental samples. Methodology: AsHCs were extracted and purified from fish oil and seaweed samples. Due to the thermal conversion of oxo-AsHCs to their trivalent forms in the injection port of the GC, the conversion is incomplete resulting in low signal intensities and large carry overs. We therefore chemically reduced AsHCs to their trivalent forms and analysed them with GC-MS, gas chromatography–tandem mass spectrometry (GC-MS/MS) and high performance liquid chromatography–inductively coupled plasma mass spectrometry (HPLC-ICPMS). The possibility for compound independent quantification with commercially available standards was investigated. Results: After optimisation of conditions for reduction of AsHCs, these compounds could be determined in marine samples using authentic standards with the new method. Results showed good agreement with results from HPLC-ICPMS. The novel GC-MS method showed compound independent quantification using triphenylarsine (TPA) as a commercially available standard. Discussion: With the developed method we could demonstrate the applicability of GC-MS for the quantitative determination of AsHCs in marine samples for the first time. The compound independent quantification with TPA opens up a quantification for AsHCs species for which no standards are commercially available. The broad applicability might enhance screening for these toxic compounds in the environment. Environmental context. The marine ecosystem is highly elevated in arsenic in comparison to the terrestrial environment. More than 100 different naturally occurring organoarsenic compounds have been found in different marine organisms. In order to understand how highly toxic AsHCs are formed and bioaccumulate in different marine organisms, large scale monitoring of AsHCs from a range of different laboratories is necessary. Despite their toxicity, AsHCs have not been extensively studied due in part to the lack of low-cost analytical methods and the lack of commercially available standards. [ABSTRACT FROM AUTHOR]

The aim of this study was to obtain baseline data for heavy metal(loids) concentrations of rice paddy fields to evaluate the impacts of soil metal(loids) concentrations on quality of rice, and to identify sources of metal(loids) pollution of paddy fields in Malawi. In total, 66 soil samples were collected from 22 different smallholder rice farmers' paddy fields (sites) in Malawi. Concentrations of metal(loids) (arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), manganese (Mn), lead (Pb), uranium (U), and gallium (Ga)) were measured using inductively coupled plasma mass spectrometry (ICP-MS) after acid block digestion with a mixture of concentrated nitric acid (70% HNO3) and hydrogen peroxide (30% H₂O₂). Measured soil metal(loids) concentrations were compared with Soil UK CLEA soil metal(loids) guidelines, maximum allowable limits (MAL) recommended by the World Health Organization (WHO), the Chinese Environmental Quality Standards (CEQS) for soil metal(loids) concentrations in agricultural soils, and the normally reported soil metal(loids) concentrations in agricultural fields worldwide. Results indicated that mean soil As (2.2 mg As kg−1), Cd (0.044 mg Cd kg−1), Pb (11 mg Pb kg−1), Co (14 ± 6 mg Co kg−1), Mn (601 mg Mn kg−1), U (2.02 mg U kg−1), and Ga (24 mg Ga kg−1) concentrations were at least three times lower than the respective guidelines and MAL recommended by WHO, UK CLEA, and CEQS (20 mg As kg−1, 0.3 mg Cd kg−1, 32 mg Pb kg−1, 50 mg Co kg−1, and 2000 mg Mn kg−1). The values obtained in this study were also within the normally reported metal(loid) concentrations for unpolluted agricultural soils worldwide. However, the mean Cr concentration (78.0 mg Cr kg−1) obtained in this study was higher than that reported for agricultural soils in China (27 ± 5 mg Cr kg−1; range: 22–39 mg Cr kg−1) but was within the normally reported Cr concentrations (1–100 mg Cr kg−1) for unpolluted soils. These findings suggest that metal(loids) concentrations of Malawian rice paddies pose no threat to production to elevated metal(loids) accumulation in rice, and that rice paddies should be safeguarded from contamination. However, further research is required to investigate the impacts of factors such as source of irrigation of water, water management regimes, soil cation exchange capacity, organic manure/composts amendments, and the application of inorganic fertilizers on uptake, transfer, and translocation of soil metal(loids) to various parts of rice plants, even when the soil metal(loids) concentrations are low. [ABSTRACT FROM AUTHOR]

A method for ultra-trace determination of Se and Te in coal by inductively coupled plasma mass spectrometry (ICP-MS) was developed. Samples (up to 500 mg) were prepared by microwave-induced combustion (MIC) in a closed system pressurized with 20 bar of oxygen. Inorganic acids or their mixtures were evaluated as absorbing solution. Using HNO3 + HCl (1 + 1), results obtained for Se and Te after sample preparation by MIC agreed with those obtained by reference methods, microwave-assisted wet digestion (MAWD) using concentrated HNO3 and HF, and solid sampling electrothermal vaporization inductively coupled plasma mass spectrometry (SS-ETV-ICP-MS), and also with a certified reference material of coal (NIST 1632c) for Se. Very low limits of quantification (LOQ) were obtained: 0.002 and 0.007 mg kg−1 for Se and Te, respectively. Major elements were determined in final solutions obtained by MAWD and MIC, and their concentration in solutions of MIC was negligible (<10 μg L−1), minimizing the risk of interference in ICP-MS analysis. The proposed method was applied to samples of coal from the United Kingdom, with a wide range of inorganic composition (from 3 to 41% ash content), showing its robustness and feasibility for routine analysis. Se concentration ranged from 0.291 to 11.5 mg kg−1, and Te was mainly found at ultra-trace levels (<0.007 to 0.11 mg kg−1). The proposed method presents several advantages over the reference methods, such as the use of a higher sample mass, low LOQs and, an important aspect, no need of using HF. [ABSTRACT FROM AUTHOR]

In this work, a method for the determination of As, Sb, Se and Te in mineral coal was developed using solid sampling electrothermal vaporization inductively coupled plasma mass spectrometry (SS-ETV-ICP-MS). The following operational parameters of the ETV-ICP-MS system were evaluated: the furnace temperature program, the mass of Ir used as the modifier, the oxygen flow rate (used in the pyrolysis step) and carrier and bypass gas flow rates. The possibility of using calibration with aqueous standard solutions was also investigated. Calibration using aqueous standard solutions was feasible for As, Sb and Te determination, and calibration using certified reference materials (CRMs) of coal was required for Se determination. For comparison of the results, coal samples were decomposed by microwave-assisted wet digestion to obtain reference values for As and Sb by ICP-MS and Se by collision/reaction cell technology inductively coupled plasma mass spectrometry (CRC-ICP-MS). In addition, samples were digested by microwave-induced combustion to obtain reference values for Te by ICP-MS. No statistical difference was observed between the results by SS-ETV-ICP-MS and those obtained by ICP-MS (As, Sb and Te) or CRC-ICP-MS (Se) after sample digestion. Additionally, CRMs of coal (NIST 1632b, NIST 1632c and NIST 1635) were analysed by SS-ETV-ICP-MS, and the results were in agreement with the certified values. The limit of quantification was 0.03, 0.01, 0.03 and 0.006 μg g−1 for As, Sb, Se and Te, respectively. These values were lower than those obtained by other methods and allowed the determination of analytes at trace and ultra-trace levels. The SS-ETV-ICP-MS method for coal presented other advantages, such as minimization of the sample preparation step, minimization of the use of large amounts of reagents and suitability of accurate determination of those analytes commonly susceptible to limitations using conventional methods. [ABSTRACT FROM AUTHOR]

This article is aimed at researchers interested in organic molecules which contain a heteroatom but who have never considered using inductively coupled plasma mass spectrometry (ICPMS) or who have used ICPMS for years and developed numerous methods for analysis of target elemental species. We try to illustrate (1) that ICPMS has been very useful for speciation analysis of metal(loid) target species and that there is now a trend to replace the costly detector with cheaper detection systems for routine target analysis, and (2) that ICPMS has been used and will be used even more in the future for non-targeted analysis of elements which are not normally associated with ICPMS analysis, such as non-metals such as sulfur, phosphorus, chlorine and fluorine. [ABSTRACT FROM AUTHOR]

Inorganic arsenic (iAs) in 13 store-bought edible seaweed samples and 34 dried kelp ( Laminaria digitata) samples was determined by a newly developed, field-deployable method (FDM) with the aid of a field test kit for arsenic in water. Results from the FDM were compared to results from speciation analysis achieved by using high performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (HPLC-ICP-MS). The FDM consisted of a simple extraction method using diluted HNO to quantitatively extract iAs without decomposing the organoarsenicals to iAs followed by the selective volatilisation of iAs as arsine (AsH) and subsequent chemo-trapping on a filter paper soaked in mercury bromide (HgBr) solution. Method optimization with a sub-set of samples showed 80-94% iAs recovery with the FDM with no matrix effect from organo-arsenic species in the form of dimethylarsinic acid (DMA) on the iAs concentration. The method displayed good reproducibility with an average error of ±19% and validation by HPLC-ICP-MS showed that the results from the FDM were comparable (slope = 1.03, R = 0.70) to those from speciation analysis with no bias. The FDM can be conducted within an hour and the observed limit of quantification was around 0.05 mg kg (dry weight). This method is well suited for on-site monitoring of iAs in seaweed before it is harvested and can thus be recommended for use as a screening method for iAs in seaweed. [ABSTRACT FROM AUTHOR]

Measuring sub-ppm levels of fluorine (F) directly with a commercial ICPMS is not possible due to the high ionisation potential of F. Mixing of barium and fluorine solutions enabled a new approach in fluorine analysis through the formation of the polyatomic ion BaF+ using ICPMS/MS. Different parameters such as reaction gas flow rate, sampling position, nebuliser and makeup gas flow rate, waiting and acquisition time as well as RF power were optimized in order to obtain the highest possible sensitivities for 138Ba19F+, as these parameters were important for polyatomic ion formation, avoiding barium oxide and barium hydroxide ion interference and sensitive detection in MS/MS. A limit of detection (LOD) of 0.043 mg L−1 was achieved with a good recovery of fluoride spiked in deionised water. For fluorine speciation analysis, coupling of anion exchange chromatography online with ICPMS/MS allowed separation and fluorine specific detection of fluoride and fluoroacetate. The response was compound independent as expected for ICPMS. The LODs of fluoride and fluoroacetate were 0.022 mg L−1 and 0.11 mg L−1, respectively. Both compounds were baseline separated and detected quantitatively, making this newly developed method a promising candidate for non-target fluorine speciation analysis in environmental samples. [ABSTRACT FROM AUTHOR]

Highlights • The total As varied by two orders of magnitude (<2.6 µg/kg to 630 µg/kg). • Cd content was always below the maximum limit established by regulatory authorities. • Upland rice from Mato Grosso contain the lowest ever measured As contents. • Brazilian rice from flooded system contains iAs from 68 to 174 µg/kg. • Twenty samples were above the limit of iAs in rice destined to food for infants. Abstract Brazil is a major producer of rice, but there is not enough information about As and Cd in rice grown under different conditions in this country. Here, As and Cd were determined by ICP-MS and species of As by HPLC-ICP-MS in Brazilian husked rice, covering diverse cultivars and regions, as well as upland and flooded production systems. Significant differences were observed for contents of both elements according to the origin of rice. All samples were below the maximum limit for Cd (400 µg/kg) set by national legislation, while nine samples presented total As above the legislation limit (300 µg/kg). From 24 samples analyzed for As species, 42% showed iAs above the European limit for production of food to infants (100 µg/kg). The total As content in samples from Mato Grosso state presented a maximum value of 6 µg/kg, which combined with low Cd content make interesting further studies. [ABSTRACT FROM AUTHOR]

A method is proposed for the determination of selenium at low concentration in coal by collision/reaction cell technology inductively coupled plasma mass spectrometry (CRC-ICP-MS). Samples were decomposed by high pressure microwave-assisted wet digestion (MAWD) using 250 mg of coal, a mixture of 5 mL of 14.4 mol L −1 HNO 3 and 1 mL of 40% HF and 70 min of heating program (200 °C and 40 bar). Hydrogen gas used in the collision/reaction cell was investigated to minimize the argon-based interferences at m/z 77, 78 and 80. The rejection parameter (RPq) and the H 2 gas flow rate were set to 0.45 and 4.8 mL min −1 , respectively. The use of H 2 in the cell resulted in other polyatomic interferences, such as 76 Ge 1 H + , 79 Br 1 H + and 81 Br 1 H + , which impaired Se determination using 77 Se, 80 Se and 82 Se isotopes, thus Se determination was carried out by monitoring only 78 Se isotope. Selenium was determined in certified reference materials of coal (NIST 1635 and SARM 20) and an agreement better than 95% was observed between the results obtained by CRC-ICP-MS and the certified values. Under optimized conditions, the instrumental limit of detection was 0.01 μg L −1 and the method limit of detection was 0.01 μg g −1 , which was suitable for Se determination at very low concentration in coal. [ABSTRACT FROM AUTHOR]

This work presents simple and reliable methods for the determination of Cd and Cr in fish oil and lipoid samples by high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS). Only a simple dilution using 1-propanol was adopted as sample preparation for the determination of Cd and Cr in order to reduce the high viscosity of the lipoid samples. Pt was employed as permanent chemical modifier and Pd was used as chemical modifier in solution, added over the sample for the determination of Cd for a better performance and sensitivity. Cr was determined without a chemical modifier. The accuracy of the proposed methods was evaluated by comparison with microwave-assisted digested samples and determination by HR-CS GF AAS, showing good agreement between 2% and 13% for both elements without statistical difference (confidence interval of 95%). The limits of detection for Cd and Cr were 0.5 pg and 7 pg, respectively, corresponding to 0.15 ng g − 1 and 2 ng g − 1 , respectively. The developed methods can be described as clean, fast and accurate, which did not require any sample pre-treatment stages, such as digestion or matrix oxidation, and could be extended to different lipoid matrices, demonstrating their robustness. [ABSTRACT FROM AUTHOR]