Abstract
A simple, selective and highly sensitive method has been developed for the determination of dialkyltin compounds in textiles. Dialkyltin compounds (di-methyl, diethyl, dipropyl and dibutyl) were separated by reversed phase HPLC on a polymethacrylate column using 10 mM phosphate buffer (pH =2.3)-methanol (30 : 70) mixture as the mobile phase. Detection was made by a fluorescence detector with an excitation wavelength of 420 nm and an emission wavelength of 500 nm after postcolumn derivatization with Morin reagent. Dioctyltin was separated from the other dialkyltin compounds on a polyvinyl alcohol-copolymer column using a 10 mM phosphate buffer (pH=2.0)- methanol (40 : 60) mixture as the mobile phase. The detection limits of dimethyl, diethyl, dipropyl, dibutyl and dioctyltin compounds were 4.5, 1.8, 2.6, 6.0 and 40 ng, respectively. Dialkyltin compounds were extracted from textiles with methanol containing 0.05% of hydrogen chloride. The extract was alkalized by sodium hydroxide and was washed with hexane. The methanolic phase was reacidified by hydrogen chloride and the dialkyltin compounds were extracted into hexane-ethyl acetate. After evaporating the organic solvent, the residue was dissolved in the mobile phase, and the solution applied to the HPLC. Dialkyltin compounds in textiles were successfully cleaned up by this preparation and determined by HPLC with good selectivity. Recoveries of dibutyltin dichloride added to various textiles at the amount of 50 μg were about 72% in average. A large amount of dibutyltin compounds was found in a diapercover (900 μg/g). And a small amount of tributyltin compounds could be detected in the same sample by ECD- GC and GC/MS, as an impurity in the dibutyltin compounds.
