DETERMINATION OF RESIDUAL FREE EPOXIDE IN POLYETHER POLYOLS BY DERIVATIZATION WITH DIETHYLAMMONIUM N,N-DIETHYLDITHIOCARBAMATE AND LIQUID-CHROMATOGRAPHY

A normal-phase liquid chromatographic method is described for the dete rmination of epoxides and particularly residual ethylene oxide and pro pylene oxide in polyether polyols. The residual epoxides are derivatiz ed with diethylammonium N,N-diethyldithiocarbamate into the correspond ing 1-(N,N-diethyldithiocarbamoyl)-2-hydroxyethane and -hydroxypropane . The dithiocarbamoyl esters are extracted into chloroform and separat ed by normal-phase liquid chromatography. Detection is done by ultravi olet at 278 nm. Total analysis time is about 45 min. Linearity (0.1-10 0 ppm), detection limits (0.5 ppm), recovery from spiked samples (>95% ) and interferences have been studied.