Speciation of Arsenic Compounds Using High-Performance Liquid Chromatography at Elevated Temperature and Selective Hydride Generation Atomic Fluorescence Detection

Understanding arsenic toxicity and metabolism requires quantitation of individual arsenic species. However, it has been difficult to separate many biochemically and environmentally important arsenic species on a single chromatography column. We have studied the separation of 11 arsenic compounds by using ion pair chromatography at 30, 50, and 70 °C column temperatures. The use of elevated column temperature improved separation efficiency and dramatically reduced chromatographic retention time for arsenobetaine, arsenocholine, tetramethylarsonium, and arsenosugars. On-line microwave derivatization combined with hydride generation and atomic fluorescence spectrometry (HGAFS) was used for detection, which was able to differentiate more toxic from less toxic arsenic species. The speciation technique was successfully applied to a study of metabolism of arseno sugars present in commercial seaweed products. Two uncharacterized arsenic-containing metabolites were detected in urine samples collected 20−33 h after ...