Development of a Novel Derivatization Reagent for the Sampling and Analysis of Total Isocyanate Group in Air and Comparison of its Performance with that of Several Established Reagents

Analytical reference standards generally are not available for non-monomeric isocyanate species, making accurate identification and quantitation by high-performance liquid chromatography (HPLC) difficult. A successful derivatizing reagent must react rapidly with all isocyanate groups, the derivatized isocyanate must be detectable selectively and at very low levels, and the detector used for quantitation must give a response proportional to the number of derivatized isocyanate groups present. A novel derivatizing reagent, 1-(9-anthracenylmethyl)piperazine (MAP), was prepared in an attempt to achieve these goals. Derivatives were prepared by reacting five mono- and difunctional isocyanates with MAP and three other established isocyanate derivatizing reagents. These reagents included 1-(2-methoxyphenyl)piperazine (MOPP), 9-(methylaminomethyl)anthracene (MAMA), and tryptamine (TRYP).The relative reactivities of MAP, MOPP, TRYP, and MAMA with phenyl isocyanate were found to be 100, 88, 30, and 25, respectively...