ANALYSIS OF NITROSAMINES 297 Table X GC-TEA Analysis of Nitrosamines Column type (length) Nitrosamine type a Reference 10% UCW-982 on Gas Chrom Q 80/100 NMODA, NMTA 25 (12ft x 2mm) 3% OV-101 on Gas Chrom 100/120 26 (10ft x 2mm) 3% Dexsil 300 on Chromosorb W AW 26 80/100 (12 ft x 2 mm) 15% FFAP on Chromosorb W 22 (2 m x 0.25 in) 10% Carbowax 20 M + 0.5% KOH on Chromosorb W/HP 80/100 (14ft X V, in) 6% OV-275 on Chromosorb WHP 80/100 (120 cm X 2.2 mm) 20% PEG-6000 (1 m X 3 mm) 15% DEGS (1 m X 3 mm) 1% XE-60 (1.5 m X 3 mm) 3% OV-17 (2 m x 3 mm) 15% SE-30 (3 m X 3 mm) 1% XE-60 (1.5 m X 3 mm) 0.5%EGA(1.5 m x 3mm) 3% OV-17 (2 rn x 3 mm) 15% SE-30 (3 rn X 3 mm) 20% PEG-6000 (1 m X 3 mm) 15% DEGS (1 m X 3 mm) 1% EDA (1.5 rn X 3 mm) 3% OV-17 (2 m X 3 mm) 15% SE-30 (3 m X 3 mm) NMODA NMODA NDMA, NDEA, NDiPA, NMPA, NDBA, NPip, NPyr, and their corresponding nitramines NDMA, NDEA, NDPA, NPip, NPyr, NMor 27 NDELA b 28, 29 o-Acyl derivatives c 59 o-Acyl derivatives c 59 o-Acyl derivatives c 59 o-Acyl derivatives c 59 o-Acyl derivatives c 59 o-Trifluoroacyl derivatives a 59 o-Trifluoroacyl derivatives d 59 o-Trifluoroacyl derivatives a 59 o-Trifluoroacyl derivatives a 59 o-Methyl ether derivatives e 59 o-Methyl ether derivatives e 59 o-Methyl ether derivatives e 59 o-Methyl ether derivatives e 59 o-Methyl ether derivatives e 59 a Nitrosamine type: NDMA, N-nitrosodimethylamine NDEA, N-nitrosodiethylamine NMPA, N-nitro- somethylpentylamine NDPA, N-nitrosodipropylamine NDBA, N-nitrosodibutylamine NDiPA, N-ni- trosodiisopropanolamine NMODA, N-nitrosomethyloctadecylamine NMTA, N-nitrosomethyltetradecy- lamine NPip, N-nitrosopiperidine NPyr, N-nitrosopyrrolidine NMor, N-nitrosomorpholine NDELA, N-nitrosodiethanolamine. b NDELA, bis-trimethylsilyl derivative of N-nitrosodiethanolamine from MSHFBA (N-methyl-N-tri- methylsilylheptafluorobutyramide). c,a,e Corresponding derivatives of hydroxylated nitrosamines including N-nitrosodiethanolamine. amino, cyano, and octadecylsilane-bonded phases (Table XI). For polar nitrosamines such as N-nitrosodiethanolamine, bonded phases that are slightly less polar than silica (such as the amino or cyano phases) are preferred since these phases tend to reduce tailing of the polar compounds (27). The overall optimization of both the chromato- graphic separation of the compounds of interest and the TEA response involves the proper choice of column and mobile phase. Chromatograms of standard nitrosamine mixtures, analyzed under different operating conditions, are shown in Figures 8 and 9. Figure 8 represents an example of volatile nitrosamines of low polarity chromatographed on a polar column (silica), while Figure 9 shows the polar nitrosamine, N-nitrosodiethanolamine, chromatographed on a less polar column (an amino-bonded phase). Characteristic in both chromatograms is the

298 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS z ! I i 5 10 15 TIME (minutes) Figure 4. GC-TEA chromatogram of a volatile nitrosamine standard mixture. Column length: 14 ft X V• in stainless steel. Column packing: 10% Carbowax 20 M plus 0.5% KOH on Chromosorb W/HP 80/100. Oven temperature: 180øC isothermal. Elution order: N-nitrosodimethylamine (NDMA), N-nitrosodieth- ylamine (NDEA), N-nitrosodipropylamine (NDPA), N-nitrosopiperidine (NPip), N-nitrosopyrrolidine (NPyr), and N-nitrosomorpholine (NMor). (Reprinted with permission from reference 27. Copyright 1979 International Scientific Communications, Inc.)