The analysis of antimony species by using ESI-MS and HPLC-ICP-MS.

A new method for the separation of organic antimony as trimethylantimony dichloride (TMSbCl2) and inorganic Sb(V) and Sb(III) by using anion exchange high-performance liquid chromatography coupled with inductively-coupled plasma mass spectrometry (ICP-MS) is presented. In comparison with previous work the detection limits for both species were significantly decreased, down to 5 ngL-1, mainly by avoiding any contamination from the Chromatographic device. Using an ultrasonic nebulizer (USN) improved the detection limits for inorganic Sb species, but was useless for the HPLC method due to problems in the recovery of the TMSbCl2. Matrix interferences of the Chromatographic determination were studied in detail and the method was applied to environmental samples assumed to contain organic antimony species. Additionally, the molecular structure of the TMSbCl2 in solution was studied by using electrospray-ionization mass spectrometry (ESI-MS) showing that this species occurs most probably as [TMSbOH]+ in aqueous solutions