Non-chromatographic speciation of toxic arsenic in vegetables by hydride generation-atomic fluorescence spectrometry after ultrasound-assisted extraction

Talanta. 2008 May 15;75(3):811-6. doi: 10.1016/j.talanta.2007.12.018. Epub 2007 Dec 26.

Abstract

A non-chromatographic, sensitive and simple analytical method has been developed for the determination of toxic arsenic species in vegetable samples by hydride generation-atomic fluorescence spectrometry (HG-AFS). As(III), As(V), dimethylarsinic acid (DMA) and monomethylarsonic acid (MMA) were determined by hydride generation-atomic fluorescence spectrometry using a series of proportional equations. The method is based on a single extraction of the arsenic species considered from vegetables through sonication at room temperature with H(3)PO(4) 1 mol L(-1) in the presence of 0.1% (w/v) Triton XT-114 and washing of the solid phase with 0.1% (w/v) EDTA, followed by direct measurement of the corresponding hydrides in four different experimental conditions. The limit of detection of the method was 3.1 ng g(-1) for As(III), 3.0 ng g(-1) for As(V), 1.5 ng g(-1) for DMA and 1.9 ng g(-1) for MMA, in all cases expressed in terms of sample dry weight. Recovery studies provided percentages greater than 91% for all considered species in spiked samples of chards and aubergines. Total toxic As found in the aforementioned samples was at the level of 90 ng g(-1); As(III) is followed by As(V), DMA and MMA which are the main species of As in chards being As(V) the main As compound in aubergines.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arsenic / analysis*
  • Arsenic / classification
  • Arsenicals / analysis*
  • Cacodylic Acid / analysis*
  • Chromatography
  • Hydrogen / chemistry*
  • Phosphoric Acids / chemistry
  • Spectrometry, Fluorescence
  • Spectrophotometry, Atomic
  • Ultrasonics
  • Vegetables / chemistry*

Substances

  • Arsenicals
  • Phosphoric Acids
  • Hydrogen
  • Cacodylic Acid
  • monomethylarsonic acid
  • Arsenic