Separation of organotin compounds by using the difference in partition behaviour between hexane and methanolic buffer solution. Part 1. Determination of butyltin compounds in textiles by graphite furnace atomic-absorption spectrophotometry

Abstract

A method for determining tributyltin compounds (TBTs) and dibutyltin compounds (DBTs) in textiles has been studied by graphite furnace atomic-absorption spectrophotometry. They are successfully extracted from textiles with methanol containing 0.05% of hydrogen chloride. Their partition between hexane and a methanolic buffer solution (pH 8.5) was studied by varying the methanol concentration of the aqueous buffer phase. Only TBTs can be extracted with hexane from a methanolic buffer solution consisting of 40 ml of methanol and 30 ml of buffer solution. TBTs are absorbed on an alumina column and eluted with a small volume of dichloromethane. DBTs remaining in the aqueous phase are extracted with dichloromethane as a complex with 4-(2-pyridylazo)resorcinol. After evaporation of the dichloromethane, the residue is heated with concentrated nitric acid and its tin concentration is determined by atomic-absorption spectrophotometry.