310 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS A B C N 0 :F ! I 10 10 11o Figure 16. HPLC-TEA chromatograms of N-nitrosodiethanolamine (NDELA) in triethanolamine lauryl sulfate on Spherisorb-CN with 2:98 (v/v) methanol-methylene chloride. Flow rate: 2 ml/min (N indicates NDELA peak). A: 200 ng NDELA. B: Triethanolamine lauryl sulfate. C: Triethanolamine lauryl sulfate q- 100 ng NDELA. D: Triethanolamine lauryl sulfate q- 200 ng NDELA. (Reprinted with permission from reference 51, Cosmetic, Toiletry and Fragrance Association.) of possible matrix interferences must be initiated for each and every type of raw material or finished product matrix to which the procedure will be applied. Eventually this involves the use of the thermal energy analyzer in conjunction with gas or high-perfor- mance liquid chromatography. INJ N I•J ! 0 Figure 17. HPLC-TEA chromatograms of N-nitrosodiethanolamine (NDELA) in Amphoteric-1 on Spheri- sorb-CN with 2:98 (v/v) methanol-methylene chloride. Flow rate: 2 ml/min (N indicates NDELA peak). A: 200 ng NDELA. B: Amphoteric-1. C: Amphoteric-1 q- 100 ng NDELA. D: Amphoteric-1 q- 200 ng NDELA. (Reprinted with permission from reference 52, Cosmetic, Toiletry and Fragrance Association.)

ANALYSIS OF NITROSAMINES 311 INS 10 INJ lO N IN. 10 C D I H, Figure 18. HPLC-TEA chromatograms of N-nitrosodiethanolamine (NDELA) in Quaternium-22 and Quaternium-7 on Spherisorb-CN with 2:98 (v/v) methanol-methylene chloride. Flow rate: 2 ml/min (N indicates NDELA peak). A: 100 ng NDELA. B: Quaternium-22. C: Quaternium-22 4- 100 ng NDELA. D: Quaternium-7. (Reprinted with permission from reference 53, Cosmetic, Toiletry and Fragrance Associ- ation. ) CHROMATOGRAPHY USING NON-TEA DETECTION Other chromatographic procedures using various types of detection systems (Tables XII and XIII) have been investigated for nitrosamine analysis. For HPLC, the ultraviolet detector is currently being employed for the analysis of N-nitrosodiethanolamine in A B C D N ' i ) INJ lO N INJ 10 INJ 10 NJ •0 Figure 19. HPLC-TEA chromatograms of N-nitrosodiethanolamine (NDELA) in morpholine on Spheri- sorb-CN with 2:98 (v/v) methanol-methylene chloride. Flow rate: 2 ml/min (N indicates NDELA peak). A: 200 ng NDELA. B: Morpholine. C: Morpholine + 100 ng NDELA. D: Morpholine + 200 ng NDELA. (Reprinted with permission from reference 49, Cosmetic, Toiletry and Fragrance Association.)