SPECIATION OF ARSENIC COMPOUNDS IN THE URINE OF RATS ORALLY EXPOSED TO DIMETHYLARSINIC ACID ION CHROMATOGRAPHY WITH ICP-MS AS AN ELEMENT-SELECTIVE DETECTOR

A combined ion chromatography (IC) with inductively coupled plasma mas s spectrometry (ICP-MS) system as an element-selective detector has be en used for the determination of arsenic compounds. Seven arsenic comp ounds were separated by cation-exchange chromatography, Subsequently, the separated arsenic compounds were directly introduced into the ICP- MS and were detected at m/z=75, Detection limits for the seven arsenic compounds ranged from 0.8 to 3.8 mu g As/l. The IC-ICP-MS system was applied to the determination of arsenic compounds in the urine of dime thylarsinic acid (DMAA)-exposed rats. DMAA was the most abundant arsen ic compound detected, Arsenous acid, monomethylarsonic acid and trimet hylarsine oxide were also detected.