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ARS Home » Research » Publications at this Location » Publication #69347
Title: SPECIATION OF ARSENIC(III) AND ARSENIC(V) IN SEDIMENT EXTRACTS BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY-HYDRIDE GENERATION ATOMIC ABSORPTION SPECTROPHOTOMETRY

Author
item Manning, Bruce
item MARTENS, DEAN - UCR, RIVERSIDE, CA

Submitted to: Journal of Environmental Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/10/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary: Arsenic (As) is a potentially toxic trace element that can similtaneously exist in more than one chemical form or species' in the environment. This paper outlines the development and application of a novel technique for separating and detecting the two most prevalent forms of As found in natural waters. Arsenite (As(III)) and arsenate (As(V)) were separated using high performance liquid chromatography (HPLC) which was linked with sensitive hydride generation-atomic absorption spectrophotometry (HG-AAS) detection. We tested the applicability of the technique by analyzing As(III) and As(V) in sequential extracts of estuarine sediments, coal fly ash, and evaporation pond sediment. The results indicated that this technique is appropriate for the detection of low levels (parts per billion) of As(III) and As(V) which are typically encountered in environmental samples.

Technical Abstract: Determining the redox states of arsenic (As) in environmental samples is important due to the pronounced differences in toxicity and mobility of the various forms. We have combined the separation capabilities of high performance liquid chromatography (HPLC) with the sensitivity and element specificity of hydride generation-atomic absorption spectrometry (HG-AAS) to determine arsenite (As(III)) and arsenate (As(V)), which have been shown to be the most toxic and prevalent forms of As in soil and water. The technique was used to determine As(III) and As(V) in deionized water and 1 mM PO4 sequential extracts of estuarine sediment (MESS-1, PACS-1, and NBS 1646) reference materials,coal fly ash (NBS 1633b), and saline evaporation pond sediments. Coal fly ash contained no detectable deionized water-extractable As(III) or As(V), but contained appreciable PO4-extractable As(V). The As(III) species was detected in all extracts of estuarine sediment, though 1 mM PO4 released primarily As(V). Evaporation pond sediment also contained primarily PO4-extractable As(V). T useful because of the growing need for routine and accurate analyses of As(III) and As(V) at trace concentrations in environmental samples.