Arsenic metabolites in human urine after ingestion of an arsenosugar

osugars) are common constituents of marine algae, in-cluding those species used as human food. The toxicol-ogy of these compounds has not been fully evaluated. Methods: Arsenic metabolites in human urine were monitored over a 4-day period after ingestion of a synthetic specimen of arsenosugar. The metabolites were determined by HPLC–inductively coupled plasma mass spectrometry, and structural assignments were confirmed with liquid chromatography–electrospray ionization mass spectrometry. Results: Approximately 80 % of the total ingested ar-senic was excreted in the urine during the 4 days of the experiment. There was a lag-period of 13 h before substantial quantities of arsenic appeared in the urine, and the excretion rate peaked between 22 and 31 h. A