Determination of hexamethylene diisocyanate in polyurethane coatings by gas chromatography with capillary column

Objective To establish the method for determination of free hexamethylene diisocyanate(HDI) in polyurethane coatings by gas chromatography. Methods Two kinds of polyurethane coatings are analyzed by gas chromatography with hydrogen flame ionization detector and the DB-17 column. Results There was a good linear relationship of this established method in the range 0.52 to 520 μg/mL. The detection limit was 0.52 μg/mL and the lowest detection concentration was 5 mg/kg(1 g taken sample). The RSD was less than 5% and the recovery rate reached 80% or more. Conclusion The experimental results showed that this method can be used to determine free hexamethylene diisocyanate content in polyurethane coatings.