Determination of dibutyltin compounds in soft polyurethane foam by gas chromatography with flame photometric detection

Abstract

A gas-chromatographic (GC) method was developed that permits the determination of dibutyltin compounds in soft polyurethane foam. Polyurethane foam and dibutyltin compounds contained in it were dissolved in sulfuric acid, and only the polyurethane was separated out by adding distilled water. Dibutyltin compounds were converted to dibutyltin dichloride by reaction with hydrochloric acid, and dibutyltin dichloride was extracted with toluene after precipitating sulfate as barium sulfate. After propylation, the organotin compound was purified by using a Sep-Pak Plus silica cartridge and was determined by GC using a DB-1 capillary column. The detection limit for dibutyltin compounds was 8.6 ng g^–1, in their chloride form. Dibutyltin compounds were detected from soft polyurethane foam at the level of 9.3–38.0 ng g^–1. The recovery of dibutyltin dichloride from soft polyurethane foam was 71.5%, when the spiked amount of dibutyltin dichloride was 5 ng.