Industrial consumption of antimony (Sb) steadily increases; as a result, the human exposure to antimony and its compounds is increasing. Since Sb has no known biological function, but has been proven to be toxic, determination of antimony in environmental and food samples is of great importance [1]. Present work describes a novel method for determination of antimony based on stibine (SbH3) generation and headspace funnel assisted single-drop microextraction coupled to UV-Vis micro-spectrophotometry. Sodium tetrahydroborate (NaBH4) has been used as reducing reagent to produce gaseous stibine molecules which subsequently react with silver diethyldithiocarbamate (AgDDC) dissolved in a mixture of 1:1 chlorobenzene:chloroform (acceptor phase) to form a red colored complex. The acceptor phase was retained in the headspace of the sample solution by the aid of a reciprocal funnel hanged at the tip of a microsyringe. Experimental parameters affecting the performance of the method such as composition and volume of the acceptor phase, sample volume, type and concentration of acid, concentrations of NaBH4 and AgDDC, stirring rate, and extraction time have been optimized. Under the optimized operating conditions, the calibration curve has been constructed which was linear in the range of 0.1 to 6 ng/ml of antimony. The limit of detection (LOD) has been determined to be 0.13 ng mL-1. The reproducibility, expressed as relative standard deviation (RSD), was 3.7% (n = 8). The applicability of the method to real analytical samples has been checked through the determination of antimony in water and pharmaceutical samples.

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