Simultaneous determination of organotin compounds in textiles by gas chromatography–flame photometry following liquid/liquid partitioning with tert-butyl ethyl ether after reflux-extraction

Abstract

A rapid and relatively clean method for determining six organotin compounds (OtC) in textile goods with a gas chromatograph equipped with a conventional flame photometric detector (GC-FPD) has been developed. After the reflux-extraction to use methanol containing 1% (v/v) of hydrochloric acid, five hydrophobic OtC (e.g. tributyltin: TBT) and slightly less hydrophobic dibutyltin (DBT) could be drawn out through partitioning between the methanolic buffer solution and tert-butyl ethyl ether instead of hazardous dichloromethane, of which usage is provided by the official-methods notified in Japan, and following the ethylation procedure to use sodium tetraethylborate, the OtC were determined with the GC-FPD. The recoveries of DBT, TBT, tetrabutyltin, triphenyltin, dioctyltin, and trioctyltin from textile products (cloth diaper, socks, and undershirt) were 60–77, 89–98, 86–94, 71–78, 85–109, and 70–79% respectively, and their coefficients of variation were 2.5–16.5%. Calibration curves for OtC were linear (0.01–0.20μgasSnmL−1), and the correlation coefficients were 0.9922–1.0000. Their detection limits were estimated to be 2.7–9.7ngasSng−1. These data suggested that this method would be applicable to their simultaneous determination. Five retailed textile goods were analyzed by this proposed method, and 0.013–0.65µgasSng−1 of OtC (e.g. DBT) were determined in three. Moreover, a possibility that various OtC including non-targeted species in textile would be specifically detected by applying the studying speciation-technique of controlling signal intensity-flame fuel gas pressures of the GC-FPD was found.