THE ANALYSIS OF ANTIMONY SPECIES BY USING ESI-MS AND HPLC-ICP-MS

A new method for the separation of organic antimony as trimethylantimo ny dichloride (TMSbCl2) and inorganic Sb(V) and Sb(III) by using anion exchange high-performance liquid chromatography coupled with inductiv ely-coupled plasma mass spectrometry (ICP-MS) is presented. In compari son with previous work the detection limits for both species were sign ificantly decreased, down to 5 ng L-1, mainly by avoiding any contamin ation from the chromatographic device. Using an ultrasonic nebulizer ( USN) improved the detection limits for inorganic Sb species, but was u seless for the HPLC method due to problems in the recovery of the TMSb Cl2. Matrix interferences of the chromatographic determination were st udied in detail and the method was applied to environmental samples as sumed to contain organic antimony species. Additionally, the molecular structure of the TMSbCl2 in solution was studied by using electrospra y-ionization mass spectrometry (ESI-MS) showing that this species occu rs most probably as [TMSbOH](+) in aqueous solutions.