Determination of total Sn in some canned beverages by FAAS after separation and preconcentration.

A micelle-mediated preconcentration method has been developed for determination of trace amounts of tin in canned beverage samples, which is widely used in food industry for packing, but its utilization is limited due to its toxic properties. The method is selectively based on the cloud point extraction (CPE) of Sn(IV) with Gallocyanin (GC(+)) and glycine as chelating agents in the mixed surfactant media, Polyethylene glycol sorbitan monolaurate (Tween 20) and Cetylpyridinium chloride (CPC) in Tris/HCl buffer, pH 8.5. The various variables affecting CPE efficiency were extensively optimized. Under the optimized conditions, the obtained calibration curve was highly linear in the range of 1-250 μg L(-1) for Sn(IV) with a good correlation coefficient of 0.9976. The detection limit of the method was 0.33 μg L(-1), and the relative standard deviations, RSDs, was in the range of 2.1-6.2% (25, 50 and 100 μg L(-1), N: 5). The matrix effect was also investigated. The method was successfully utilized for the determination of total Sn in some canned beverages by Flame Atomic Absorption Spectrometry (FAAS). Its validity was controlled by the analysis of two certified reference materials. It has been observed that the results are in agreement with the certified values.