Zhilong Gong

Arsenic speciation analysis

Nearly two dozen arsenic species are present in the environmental and biological systems. Differences in their toxicity, biochemical and environmental behaviors require the determination of these individual arsenic species. Considerable analytical progresses have been made toward arsenic speciation analysis over the last decade. Hyphenated techniques involving a highly efficient separation and a highly sensitive detection have become the techniques of choice. Methods based on high-performance liquid chromatography separation with inductively coupled plasma mass spectrometry, hydride generation atomic spectrometry, and electrospray mass spectrometry detection have been shown most useful for arsenic speciation in environmental and biological matrices. These hyphenated techniques have resulted in the determination of new arsenic species, contributing to a better understanding of arsenic metabolism and biogeochemical cycling. Methods for extracting arsenic species from solid samples and for stabilizing arsenic species in solutions are required for obtaining reliable arsenic speciation information.

Trivalent arsenic species: Analysis, stability, and interaction with a protein

Publisher Summary Biomethylation is the major metabolic process for inorganic arsenic (As). The methylation process involves stepwise two-electron reduction of As, followed by oxidative addition of a methyl group. Methyltransferases are responsible for methyl transfer, and S-adenosyl-methionine (SAM) is the methyl donor. Trimethylarsine oxide (TMAOV) and trimethylarsine (TMAIII) are the end products formed by some microorganisms. Dimethylarsinic acid (DMAV) is the usual end product detected in humans, although dimethylarsinous acid (DMAIII) has recently been detected in human urine. An important issue regarding the speciation of monomethylarsonous acid (MMAIII) and dimethylarsinous acid (DMAIII) is the stability and preservation of these species. It has been reported that MMAIII and DMAIII are less stable than the other As species, suggesting that new strategies for sample handling are needed for the analysis of these trivalent As species.

Trivalent arsenic species

Publisher Summary Biomethylation is the major metabolic process for inorganic arsenic (As). The methylation process involves stepwise two-electron reduction of As, followed by oxidative addition of a methyl group. Methyltransferases are responsible for methyl transfer, and S-adenosyl-methionine (SAM) is the methyl donor. Trimethylarsine oxide (TMAOV) and trimethylarsine (TMAIII) are the end products formed by some microorganisms. Dimethylarsinic acid (DMAV) is the usual end product detected in humans, although dimethylarsinous acid (DMAIII) has recently been detected in human urine. An important issue regarding the speciation of monomethylarsonous acid (MMAIII) and dimethylarsinous acid (DMAIII) is the stability and preservation of these species. It has been reported that MMAIII and DMAIII are less stable than the other As species, suggesting that new strategies for sample handling are needed for the analysis of these trivalent As species.

Chapter 4 – Trivalent arsenic species: Analysis, stability, and interaction with a protein

Publisher Summary Biomethylation is the major metabolic process for inorganic arsenic (As). The methylation process involves stepwise two-electron reduction of As, followed by oxidative addition of a methyl group. Methyltransferases are responsible for methyl transfer, and S-adenosyl-methionine (SAM) is the methyl donor. Trimethylarsine oxide (TMAOV) and trimethylarsine (TMAIII) are the end products formed by some microorganisms. Dimethylarsinic acid (DMAV) is the usual end product detected in humans, although dimethylarsinous acid (DMAIII) has recently been detected in human urine. An important issue regarding the speciation of monomethylarsonous acid (MMAIII) and dimethylarsinous acid (DMAIII) is the stability and preservation of these species. It has been reported that MMAIII and DMAIII are less stable than the other As species, suggesting that new strategies for sample handling are needed for the analysis of these trivalent As species.