The Use of Two Extraction Procedures in Combination with Electrothermal AAS for Speciation of Inorganic Antimony in Natural Waters

Abstract

For speciation of inorganic Sb before its determination by electrothermal AAS, two extractions were used. Solid phase extraction (SPE) with nanosized TiO₂ as a sorbent was performed in separation/preconcentration of total inorganic Sb and subsequent direct sampling of TiO₂ slurry for sample injection into a graphite tube. The cloud point extraction (CPE) with ammonium pyrrolidinecarbodithioate as a chelating agent and hydrogen-octylphenoxy-poly(oxyethylene) (Triton X-114) as a nonionic surfactant were used in selective separation/preconcentration of Sb(III). Main attention was paid to interference of coexisting ions in the extractions and to that of Sb(V) excess in the CPE separation/preconcentration of Sb(III). The accuracy of the optimized methods was checked by a certified reference material for trace elements in lake water. The optimized methods were used for speciation of inorganic Sb in natural waters.