Determination of dibutyltin and dioctyltin compounds in PVC food containers, wrappage and clothes by reversed phase HPLC with column switching.

Abstract

Dibutyltin (DBT) and dioctyltin compounds (DOT) in polyvinyl chloride (PVC) food containers, wrappage and clothes were determined by reversed phase HPLC based on post column fluorescence derivatization. The two dialkyltin compounds were extracted from PVC food containers and wrappage with carbon tetrachloride-methanol solution, and from clothes with methanol containing 0.1% hydrogen chloride. After evaporating the extract to a few ml, the condensed solution were diluted with methanol, and applied to the HPLC. DOT was determined by a polyvinylalcohol-copolymer column (Asahipak GS-310H) by using 10 mM phosphate buffer (pH = 2.0)-methanol (4:6) mixture as a mobile phase at 40.degree.C. For removal of the influence of a large amount of DOT, column switching system was applied for the determination of DBT. After DBT was separated from DOT on a polymethacrylate pre-column (Shodex DE-613p) by using 10mM phosphate buffer (pH = 2.3)-methanol (5:5) mixture as a mobile phase, switched valve, and DBT was determined on a polymethacrylate analytical column (Shodex DE-613) by using the same mobile phase at 35.degree.C. Detection limit of DBT and DOT were 10ng, respectively. Recoveries of DBT and DOT added to PVC food containers and wrappage at the amount of 20.mu.g/g were both 98%. And their recoveries added to clothes at the amount of 100.mu.g/g were both 100%. DOT was detected in six PVC food containers, and DBT was also detected in two PVC food containers. DOT was detected in eight diapercovers, and DBT was detected in a diapercover. The present method is applicable for the rapid and simple routine analysis of DBT and DOT in clothes and PVC food containers and wrappage.