GAS-CHROMATOGRAPHIC DETERMINATION OF INORGANIC TIN IN RAT URINE AFTER A SINGLE ORAL-ADMINISTRATION OF STANNOUS CHLORIDE AND MONOPHENYLTIN, DIPHENYLTIN, AND TRIPHENYLTIN CHLORIDE

A method is described for the determination of inorganic tin by gas chromatography with flame photometric detection. The inorganic tins, stannous and stannic, were extracted with hydrochloric acid and n-hexane-benzene in the presence of 0.05% tropolone, and both inorganic tins were pentylated to tetrapentyltin with a Grignard reagent prior to gas chromatography. The absolute limit of detection for tetrapentyltin was 3 pg as tin. The recovery of stannous chloride added to rat urine samples was 80.2 +/- 2.4% (mean +/- S.D., n = 8). The application of this method to the study of urinary excretion of inorganic tin and organotin compounds in rats following oral administration of tin compounds is presented. The urinary excretion of tin compounds was observed over a period of 96 h following administration of stannous chloride or phenyltin compounds. Most of the inorganic tin was excreted into urine within 24 h after administration of stannous chloride. In the experiments on organotin administration, the level of the excretion as total tin for monophenyltin reached a maximum ca. 0-24 h after administration, whereas the maxima for di- and triphenyltin were found after 24-48 h and 48-72 h, respectively. The predominant excretion product of these tin compounds found in urine was monophenyltin.