Takeuchi, M; Mizuishi, K; Yamanobe, H; Watanabe, Y; Doguchi, M
A method for the determination of tributyltin (TBT) and triphenyltin (TPT) compouds in fish and shellfish samples was developed by electon capture detection GC. Five grams of homogenized samples were shaken with 10 ml of methanol-ethyl acetate (1: 1, v/v) and 10 ml of 0.5 M hydrochloric acid for 10 min. The resulting tributyltin chloride (TBTC) and triphenyltin chloride (TPTC) were each extracted three times with 50 ml of hexane-diethyl ether (3: 1, v/v). After adding 0.5 ml of nonane, the combined organic phase was concentrated to less than 1 ml. The concentrate was adjusted to 5 ml with hexane-diethyl ether (3: 1, v/v) and poured into a 30X1.0 cm i.d. glass column packed with 3g of Florisil and 2 g of anhydrous sodium sulfate. The column was washed with 40 ml of hexane-diethyl ether (3: 1, v/v) and 70 ml of hexane-acetone (3: 1, v/v), and eluted with 40 ml of hexane-diethyl ether-acetic acid (75: 25:1,v/v/v). After adding 0.5 ml of nonane, the eluate was concentrated to less than 1 ml by a rotary evaporator. The concentrate was adjusted to 5 ml with hexane-diethyl ether (3: 1, v/v), and washed with half the volume of 1M NaOH~5% NaCl (1: 1, v/v). After centrifugation, the organic phase was neutralized with 20 $$l/ml of hexane-diethyl ether-acetic acid (75:25:1, v/v/v) and submitted to GC. The GC column used was 1.0 mX3.2 mm i.d. glass tube packed with 2% Silicone OV-225 on Uniport HP (60~80 mesh) pretreated by the following procedure: After conditioning at 260°C for 20 h, the colume was cooled to 150°C, injected 10 times with 5µl of hydrobromic acid (47%)-methanol (1: 100, v/v), heated to and maintainedat 240°C for 2 h. As a result of pretreatment of the column, TBTC and TPTC injected were converted into tributyltin bromide and triphenyltin bromide and detected on the chromatogram as very shape peaks. The recoveries of TBTC and TPTC from fish and shellfish samples by this method were more than 90% and the relative standard deviations were 3~5%. The determination limits of TBT and TPT were less than 0.005 µg/g as TBTC and TPTC, respectively. © 1989, The Japan Society for Analytical Chemistry. All rights reserved.
