A simple, inexpensive and convenient procedure for determination of inorganic Sb species in milk and beverage samples in PET containers by flame atomic absorption spectrometry

Abstract

A simple and efficient Cloud Point Extraction (CPE) method has been proposed for separation and preconcentration of inorganic Sb species. The method is based on stable hydrophobic complex formation of Sb(III and V) with Pyronin B in the presence of sodium dodecyl sulfate (SDS) as both an auxiliary ligand and sensitivity improvement agent, and polyethylene glycol tert-octylphenyl ether (Triton X-114) as the extracting agent at pH 2.0. The inorganic Sb species were detected and quantified by flame atomic absorption spectrometry (FAAS). Under the optimized conditions, the limits of detection of 1.68 and 4.28 μg L⁻¹ for Sb(III) and Sb(V) along with sensitivity improvement factors of 117.6 and 83.4 respectively, were obtained. The method was successfully applied to a reliable determination of Sb(III and V) and total Sb in beverage and milk samples, and the recoveries in the range of 97.0–100.6% were obtained from the spiked samples. The accuracy was checked by analysis of two certified reference materials (CRMs) with a matrix similar to that of the samples. The values obtained were in accordance with those reported for the certified values.