An Inexpensive and Sensitive Method for Speciative Determination of Sn(IV), Sn(II), and Total Sn as Sn(IV) in Selected Beverages by Micellar Improved Spectrophotometry

Abstract

In the present study, an inexpensive, selective, and micellar sensitive spectrophotometric method for Sn(IV) was developed at 537 nm. The method is based on the formation of ternary complex of Sn(IV) with tartaric acid and Celestine blue in the presence of sodium dodecyl sulfate (SDS) and polyethylene glycol tert-octylphenyl ether (Triton X-114) at pH 3.5. The analytical variables affecting cloud point extraction (CPE) efficiency were optimized in detail. Under the optimized conditions, the calibration graph was linear in the range of 4–350 μg L−1 with changing dye concentration for Sn(IV) ions. The limits of detection and quantification of the method were found to be 1.3 and 4.3 μg L−1 for Sn(IV), respectively. Relative standard deviation (RSDs) for five replicate determinations at 20 and 100 μg L−1 concentration levels were 4.4 and 1.5 %, respectively. Recovery values of spiked samples were obtained in range of 97.7–103.3 %. Matrix effect on the extraction efficiency were also investigated. The method was successfully applied to the determination of Sn(II), Sn(IV) and total Sn in some selected beverages before and after pretreatment with H2O2 in acidic media, prior to analysis. Validity of the method was controlled through the analysis of two certified reference materials. It has been observed that the results are highly compatible with the certified values.