Arsenic Speciation Analysis in Environmental and Biological Systems

Abstract

My thesis research focused on the development and application of analytical methods that enabled arsenic speciation in biological and environmental samples. A set of complementary chromatographic separation techniques were combined with inductively coupled plasma mass spectrometry and hydride generation. These techniques allowed for the separation and detection of arsenobetaine, arsenite, arsenate, monomethylarsonic acid, and dimethylarsinic acid. The application of these techniques to the determination of arsenic species in human urine has contributed to arsenic exposure measurement in a collaborative pilot epidemiological study. The application of a high performance liquid chromatography – inductively coupled plasma mass spectrometry technique showed that most of the groundwater samples from the Battersea Drain watershed located in southern Alberta had arsenic concentrations below the Canadian drinking water guideline value of 10 µg L-1. A set of complementary chromatographic separation techniques coupled with inductively coupled plasma mass spectrometry was developed to characterize a new arsenic species, Arsenicin A, previously reported for the presence in a marine sponge. These techniques enabled the separation and detection of an Arsenicin A model compound, arsenite, arsenate, monomethylarsonic acid, dimethylarsinic acid, arsenobetaine, and an arsenosugar. The application of these techniques to the determination of arsenic species in marine sponges suggested that arsenic speciation profile may be organism and habitat dependent. A comparative cellular uptake study that used human lung carcinoma A549 cells showed that these cells were able to uptake two orders of magnitude more Arsenicin A model compound than arsenite. The higher cellular uptake of Arsenicin A model compound was consistent with the higher toxicity of Arsenicin A model compound as compared to arsenite, suggesting that the cellular uptake is an important factor contributing to the toxicity of these arsenic species. My Ph.D. research has provided analytical techniques that are useful to environmental and biological studies.