A Method for Determination of Organic Tin Compounds in Raw Starch

Abstract

In Aichi prefecture diethyl benzyl tin hydroxide, one of organic tin compounds, added to raw starch as food additive was detected. Its content was about 5ppm. From the view of food hygiene, it is dangerous. This is the first case that diethyl benzyl tin hydroxide was used for the preservation of raw starch. Accordingly identification method of organic tin compound has not been found except for the method which is restricted to identify metallic tin.Of gas chromatography, infrared absorption spectrum, and thin layer chromatography, good results were obtained only by the latter method as follows: Not only diethyl benzyl tin hydroxide but tributyl tin acetate, triphenyl tin acetate and bis tributyl tin oxide were able to be identified by the “double T. L. C.” method. Linear calibration curve was obtained by each of them at the maximum absorption wave length by UV absorption method, which corresponded with the Beer's law, the quantitative analysis being found to be possible. Then we added diethyl benzyl tin hydroxide to raw starch produced in our laboratory and examined its recovery test. After the experience, their recoveries were 87.8-91.5%. From the above, this method seems to be excellent for detecting organic tin compounds.