ANALYSIS OF NITROSAMINES 299 4 8 12 16 20 24 TIME (minutes) Figure 5. GC-TEA chromatograms of seven nitrosamines and their corresponding nitramines. Column length: 2 m X 2 mm glass. Column packing: 15% FFAP on Chromosorb W. Oven temperature: 170øC isothermal. Nitrosamine peaks: (1) N-nitrosodimethylamine, (2) N-nitrosodiethylamine, (3) N-nitrosodi- propylamine, (4)N-nitrosomethylpentylamine, (5)N-nitrosodibutylamine, (6)N-nitrosopiperidine, (7) N-nitrosopyrrolidine. Nitfamine peaks: (8) N-nitrodimethylamine, (9) N-nitrodiethylamine, (10) N-ni- trodipropylamine, (11) N-nitromethylpentylamine, (12) N-nitrodibutylamine, (13) N-nitropiperidine, (14) N-nitropyrrolidine. (Reprinted with permission from reference 22. Copyright 1980 Elsevier Science Publishers.) broadening of the component peak with increasing retention time. This is common in all chromatographic separations, since there is increased interaction between the later eluting components and the bonded phase. Results of HPLC-TEA techniques applied to some cosmetic matrices are presented in Figures 10-12. The effects of using different columns for the determination of N-ni- trosodiethanolamine are illustrated in Figure 10. Chromatography using a silica or cyano column achieves relatively good resolution. However, when a size exclusion

300 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS g I ! i • 4 8 12 16 'rIME (minutes) Figure 6. GC-TEA chromatogram of N-nitrosomethyldodecylamine (NDOMA) and N-nitrosomethylte- tradecylamine (NMTDA) in a hair-care product. Column length: 12 ft X 2 mm glass. Column packing: 10% UCW-982 on Gas-Chrom Q 80/100. Oven temperature: 210øC isothermal. (Reprinted with permis- sion from reference 25. Copyright 1982 Pergamon Press.)