Determination of isocyanate groups in the organic intermediates by reaction-based headspace gas chromatography

This work reports on a novel method for the determination of isocyanate groups in the related organic intermediates by a reaction-based headspace gas chromatography. The method is based on measuring the CO2 formed from the reaction between the isocyanate groups in the organic intermediates and water in a closed headspace sample vial at 45 degrees C for 20 min. The results showed that the method has a good precision and accuracy, in which the relative standard deviation in the repeatability measurement was 5.26%, and the relative differences between the data obtained by the HS-GC method and the reference back-titration method were within 9.42%. The present method is simple and efficient and is particularly suitable to be used for determining the isocyanate groups in the batch sample analysis. (C) 2016 Elsevier B.V. All rights reserved.