Abstract
The applicability of the hydride generation (HG) sample introduction technique combined with different spectrochemical detection methods for non-chromatographic speciation of toxic As species, i.e., As(III), As(V), dimethylarsinate (DMA) and monomethylarsonate (MMA), in waters and other environmental, food and biological matrices is presented as a promising tool to speciate As by obviating chromatographic separation. Different non-chromatographic procedures along with speciation protocols reported in the literature over the past 20 year are summarized. Basic rules ensuring species selective generation of the corresponding hydrides are presented in detail. Common strategies and alternative approaches are highlighted. Aspects of proper sample preparation before analysis and the selection of adequate strategies for speciation purposes are emphasized.
Highlights
Because the toxicity and physiological behavior of various As compounds differ greatly, knowledge regarding As species is crucial to understand their potential harmful effects to human beings
Regarding individual speciation, a simple procedure for the determination of As(III) and inorganic arsenicals (i-As) in phosphate fertilizers by hydride generation (HG)-atomic absorption spectrometry (AAS) was described by Rezende et al [36], in which samples were sonicated for 35 min with 0.35% Triton X-114 and 6.5 mol L−1 HNO3
In terms of toxicological investigations, knowledge of As species is crucial to understanding the potentially harmful effects associated with exposure to this element
Summary
Because the toxicity and physiological behavior of various As compounds differ greatly, knowledge regarding As species is crucial to understand their potential harmful effects to human beings. D As non-toxic, i.e., unreactive As forms toward HG (mainly AsB) calculated as the difference between total As (determined after digestion) and the hydride-active toxic As species, i.e., the sum of As(III)+As(V)+DMA+MMA. The HG technique, originally developed to separate As from the sample matrix, was found to be a viable method by which to discriminate among major toxic As compounds, i.e., i-As, DMA and MMA. The ability of the HG technique to differentiate As forms by their oxidation state (III/V) or nature (inorganic/organic) using simple procedures certainly broadens the application range of HG regarding As speciation, without the use of chromatographic separation (see Table 1). Instrumental Techniques Used for the Determination of As Species and Ways of Verifying the
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