Combination of a GC-TEA and a GC-MS-data system for the microgram/kg estimation and confirmation of volatile N-nitrosamines in foods.

An analytical procedure has been outlined in which volatile N-nitrosamines in foods are isolated by vacuum distillation, cleaned up, identified and quantified by GC-TEA and qualitatively confirmed by GC-MS, coupled with a data system. Spectra are presented which demonstrate that this technique is capable of confirming NDMA and NPYR in a variety of foods at levels of 1 to 10 micrograms/kg. Unequivocal confirmation is based on three types of evidence: (1) the compound is TEA positive; (2) the compound has the correct retention time on a packed and on a capillary column; (3) the complete mass spectrum closely matches standard spectra. These procedures have been used to confirm the presence of trace levels of NDMA in domestic beer and in non-fat dry milk.