Comparison of extraction procedures for arsenic speciation in environmental solid reference materials by high‐performance liquid chromatography–hydride generation‐atomic fluorescence spectroscopy

Abstract

International audienceWater and 'soft' extractions (hydroxylammonium hydrochloride, ammonium oxalate and orthophosphoric acid) have been studied and applied to the determination of arsenic species (arsenite, arsenate, monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA)) in three environmental solid reference materials (river sediment, agricultural soil, sewage sludge) certified for their total arsenic content. The analytical method used was ion exchange liquid chromatography coupled online to atomic fluorescence spectroscopy through hydride generation. Very low detection limits for arsenic were obtained, ranging from 0.02 to 0.04 mg kg-1 for all species in all matrices studied. Orthophosphoric acid is the best extractant for sediment (mixed origin) and sludge samples (recent origin) but not for the old formation soil sample, from which arsenic is extracted well only by oxalate. Both inorganic forms (As(III) and As(V)) are significant in all samples, As(V) species being predominant. Moreover, organic forms are found in water extracts of all samples and are more important in the sludge sample. These organic forms are also present in the 'soft' extracts of sludge. Microwave-assisted extraction appears to minimize the risk of a redox interconversion of inorganic arsenic forms. This study points out the necessity of combining direct and sequential extraction procedures to allow for initial arsenic speciation and to elucidate the different mineralogical phases-species associations. Copyright © 2002 John Wiley & Sons, Ltd

Determination of four arsenic species in soil by sequential extraction and high performance liquid chromatography with post-column hydride generation and inductively coupled plasma optical emission spectrometry detection

“…25,[27][28][29][30] Mixtures of phosphate with either ethylenediaminetetraacetic acid, hydroxylamine hydrochloride, or sodium diethyldithiocarbamate have been evaluated. 30 …”

“…The most promising of the previously reported extractants, 25,[27][28][29][30] solutions of ammonium acetate, ammonium bicarbonate, ammonium carbonate, phosphoric acid, and sodium hydroxide were prepared at different concentrations (0.10, 0.50 and 1 mol l…”

Major Factors Controlling Arsenic Occurrence in the Groundwater and Sediments of the Chianan Coastal Plain, SW Taiwan

“…Then the samples were dried with a freeze-vacuum chamber before chemical extraction analysis. At present, there is no well accepted standard method for single or sequential extractions of As in soil and sediments (e.g., Keon et al 2001;Montperrus et al 2002). In this study, arsenic associated with relatively mobile phases [Fe-Mn-(hydr)oxides and organic matter] in the sediments was extracted by the method developed by Ellwood and Maher (2003).…”

Atomic Fluorescence Spectrometry: a suitable detection technique in speciation studies for arsenic, selenium, antimony and mercury

“…Both phosphoric acid and ascorbic acid solutions have been applied for extraction of polluted mining soil 54,55 or reference materials (river sediment, agricultural soil, and sewage sludge). 56,57 The extraction yield is improved by shaking, ultrasonic and microwave assisted extraction.…”