Application of tryptamine as a derivatizing agent for the determination of airborne isocyanates. Part 6. Confirmation of the concept of isolation of a selected π-system of a derivative for specific high-performance liquid chromatographic detection through analysing bulk materials for total isocyanate content

Abstract

Bulk materials containing polymeric isocyanates were employed to evaluate the practicality of a previously proposed concept of isolation of a selected π-system of a derivative for specific high-performance liquid chromatography (HPLC) detection. The application of this concept to the determination of isocyanato groups in polymeric components, which often have no defined structures, was assumed on theoretical grounds but not validated. The amount of tryptamine-derivatized isocyanato groups in polymeric components was determined with a reversed-phase HPLC system equipped with a fluorescence detector. Tryptamine-derivatized toluene diisocyanate was the only calibration standard used for all quantifications. The amount of indolyl moieties in the derivatized polymeric components was correlated satisfactorily with the amount of tryptamine depleted during derivatization.