Coupled chromatography-atomic spectrometry for arsenic speciation—a comparative study

Abstract

Several methods for the quantitative determination of different forms of arsenic (Asl", As", monomethyl and dimethyl) in a variety of samples are described and compared. In each instance separation is achieved by chromatographic means, using either gas (GC) or high-performance liquid chromatography (HPLC), with detection by atomic spectrometry, namely flame atomic absorption spectrometry (FAAS), flame atomic fluorescence spectrometry (FAFS) and inductively coupled plasma atomic emission spectrometry (ICP-AES). For the GC separation it is necessary to derivatise the As compounds either as the hydrides or as the methylthioglycolates. As the arsenic hydrides can be pre-concentrated using cryogenic trapping, this yields the lowest detection limits. The As species studied can be separated without derivatisation by HPLC but after HPLC separation hydride generation can be used to increase the sensitivity for FAAS, FAFS and ICP-AES.While each technique is best suited to certain applications, the hydride generation -cryogenic trapping -GC -FAAS system is capable of detection at the sub-p.p.b. level (0.22-0.55 ng absolute for different species) and is preferred for low-level As samples. When levels permit, HPLChydride generation -FAAS is probably the simplest routine method and HPLChydride generation -ICP-AES will probably be preferred for multielement analysis.

Flow Injection Hydride Generation Atomic Absorption Spectrometry for Determination of Arsenic in Water and Biological Samples from Arsenic-Affected Districts of West Bengal, India, and Bangladesh

“…It is extremely important that the analytical method applied is capable of distinguishing these forms from the more complex but nontoxic organoarsenicals. A number of techniques have been reviewed for speciation of arsenic compounds (37,41,42). The most widely used speciation techniques are ion-exchange separation followed by HG-AAS (4,43), HPLC in combination with ICP (44,45), ICP-MS combined with HPLC (19, 46 -48), HPLC-HG-AAS (42,49,50), and HPLC-HG-AFS (23,51).…”

Metal ion speciation and capillary electrophoresis: Application in the new millennium

“…Still there is a need of speciation at fast and inexpensive levels which is fulfilled, up to some extent by CE. Since 1990s, there has been growing interest in metal ion speciation by CE [2][3][4][5][6]. Many improvements and advances have been reported from time to time to make CE a good alternative for metal ion speciation.…”

Speciation of arsenic in baby foods and the raw fish ingredients using liquid chromatography-hydride generation-atomic absorption spectrometry

“…When these are coupled to a separation system, information on speciation instead of the total concentration or amount of arsenic is provided [1]. Arsenic-containing compounds subject to speciation analysis are anions, e.g.…”