SPECIATION OF ANTIMONY(III) AND ANTIMONY(V) SPECIES BY USING HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY COUPLED TO HYDRIDE GENERATION ATOMIC-ABSORPTION SPECTROMETRY

A miniaturized HPLC column (Supelcosil LC-SAX 1, 2 cm x 4.6 mm id) was coupled to HGAAS for the speciation of inorganic Sb-III and Sb-V spec ies in spiked water samples, The baseline separation of these two Sb s pecies was achieved by using aqueous 50 mmol 1(-1) tartrate solution a t pH 5.5 as eluent, The retention times were 0.5 and 2.8 min for Sb-V and Sb-III, respectively, The hydrides were generated with 3% NaBH4 an d 1.8 mol 1(-1) HCl solutions, The absorbance was Linearly related to the concentration of Sb-V species in the range 2.5-100 mu g 1(-1) (n = 0.9996) and of Sb-III species in the range 5.0-100 mu g 1(-1) (n = 0. 9990) with detection limits of 1.0 and 2.0 mu g 1(-1), for Sb-V and Sb -III, respectively. The precision, evaluated by using the relative sta ndard deviation (RSD), was 3.3% and 1.5% (n = 10) for Sb-V and Sb-III at concentrations of 50 mu g 1(-1), and 4.1% and 3.9% (n = 10) at conc entrations of 10 mu g 1(-1), respectively, The detection limits achiev ed in the present work are acceptable for screening samples with respe ct to the EU drinking and surface water limits (10 mu g 1(-1)), but ar e not sufficiently sensitive to measure real levels in natural waters, The accuracy of the method was evaluated by the analysis of Sb specie s in several spiked water samples, as there is yet no certified refere nce material available.