Nonvolatile N-nitrosamine investigations: methods for the determination of N-nitrosoamino acids and preliminary results of the development of a method for the determination of N-nitrosodipeptides N-terminal in proline.

The development of a rapid method for the determination of N-nitrosoamino acids is reported. Preliminary recoveries of N-nitrosoamino acids in ham fortified with 20 micrograms/kg generally ranged from 70 to 100%. The synthesis and instrumental characterization of four N-nitrosodipeptides N-terminal in proline from nitrite in aqueous acid solution are reported. Electron ionization-mass spectroscopy and infra-red spectroscopy strongly support the conclusion that only the amine nitrogen, and not the amide nitrogen at the peptide bond, is nitrosated. High-performance liquid chromatographic conditions are described for the separation of the synthesized N-nitrosodipeptides.