DETECTION OF MONOMERIC HEXANE DIISOCYANATE IN AQUEOUS EXTRACTS OF A POLYURETHANE DEVICE AS AN ARTIFACT OF INJECTION PORT PYROLYSIS IN GAS-CHROMATOGRAPHY

During stability studies aqueous extractions were carried out on a pol yurethane (PU) device. Analysis of the extracts, reconstituted in tetr ahydrofuran (THF), gave strong positive results for free monomeric hex ane diisocyanate (HDI) when analysed by gas chromatography with mass s pectroscopic detection (GCMS). Given that aqueous media were under inv estigation it was considered impossible that free monomer could have s urvived the preparation process and that its detection was an artefact of injection port pyrolysis. High performance liquid chromatography ( HPLC), a technique which does not impose thermal stress, was used to a nalyse the same samples to demonstrate that HDI was formed as a result of injection port pyrolysis of polymer alone. Safety concerns for the product were thus addressed. (C) 1998 Elsevier Science Limited. All r ights reserved.