A New Reagent for Determination of Isocyanates in Working Atmospheres by HPLC Using UV or Fluorescence Detection

Abstract

Abstract A new liquid chromatographic method with increased sensitivity has been developed for the determination of isocyanates common in industrial environments. The isocyanates are converted to stable urea derivatives by reaction with 9-(N-methylaminomethyl)-anthracene. These derivatives were analyzed using high performance liquid chromatography on a bonded octadecylsilyl phase using isocratic elution with acetonitrile/water and detected either by a UV or a fluorescence detector. The method was applied to toluene 2, 4- and 2, 6-diisocyanate (2, 4- and 2, 6-TDI), hexamethylene diisocyanate (HDI) and 4, 4-diphenylmethane diisocyanate (MDI). The influence of various salts on the retention of the reagent amine was studied, as well as the separation of the urea derivatives on different C18-phases. The detection limit is about 1 · 10−4 mg/m3 for the isocyanates investigated, using either UV or fluorescence detection. This means that the new method is ten to twenty times more sensitive than the previously desc...