A SEC-HPLC-ICP MS hyphenated technique for identification of sulfur-containing arsenic metabolites in biological samples

The present study describes the synthesis and characterization of thioarsenicals using electro-spray ionization-MS and time of flight-MS. Separation of thioarsenicals was found to be better by size-exclusion column compared to anion exchange column coupled with HPLC-inductively coupled argon plasma mass spectrometer (ICP MS). Although four thioarsenicals were confirmed as dimethylthioarsinous acid (m/z = 138), methylmonothioarsonous acid (m/z = 122), dimethyldithioarsinic acid (m/z = 170) and methyltrithioarsonic acid (m/z = 188), it is noted that HPLC-ICP MS alone were not sufficient for their identification. Also, none of them was stable with time. This is the first report detailing the synthesis and identification of methyltrithioarsonic acid. Both dimethyldithioarsinic acid and dimethylthioarsinous acid were detected in human nail samples while dimethyldithioarsinic acid was found in urine samples. So, the above technique could be applicable to the identification of sulfur-containing biomolecules in the biological samples.