Gas chromatographic/mass spectrometric analysis of extracts of workplace air samples for nitrosamines

Three capillary gas chromatography/mass spectrometry (GC/MS) procedures were developed to confirm the presence of N-nitrosamines in workplace air sample extracts, which were previously analyzed by gas chromatography with a thermal energy analyzer. In the first procedure, high resolution ion monitoring of NO+ was used to confirm the presence of eight N-nitrosamines and to screen the samples for other N-nitroso compounds. In the second procedure, high resolution monitoring of parent ions was used for confirmation of specific N-nitrosamines; and in the third procedure, full-scan GC/MS was used for identification of compounds above the level of 2 ng per injection. Detection limits of the three procedures and retention time precision of both selected ion monitoring techniques are given. Typical examples in the use of these techniques for confirmation of N-nitrosamines in sample extracts also are described.