Fast gas chromatography analysis of N-carbamates with cold on-column injection.

Direct gas chromatographic (GC) analysis of thermally labile N-carbamates is studied by using fast GC with cold on-column injection. With the greatly reduced injection temperature, short column lengths, high flow rate, and fast temperature-programming rate, the exposure of carbamates to high temperature is reduced and degradation can be avoided. Nine N-carbamates in EPA Method 531 are eluted without thermal decomposition. The relative standard deviation percentage for peak areas average 1.9% for all of the carbamates analyzed. A conventional GC instrument is employed to simplify the experiments. GC-mass spectrometry is used to monitor the decomposition peaks.