NITROSAMINE ANALYSIS 249 (a) NDE1A AREAS (b) I INJECTION POINTS Figure 3. Chromatogram of reinjected spiked sample (a) and unspiked sample (b) isolated from cocamide DEA. a /zBondapak column, and even with a faster flow rate, the NDE1A peak is better resolved from the solvent front and other early eluting peaks. Quantitation of the unspiked cocamide DEA sample was 250 ppb, which compares favorably with the level found using the/zBondapak C•8 column. EXTENSION OF HPLC-UV ANALYSIS TO A FINISHED PRODUCT The analysis of raw materials for NDE1A is of prime importance to prevent an adulterated material from being introduced into a cosmetic product. It is also apparent that a routine method to monitor finished products for NDE1A is needed. Generally, the published methods for NDE1A in finished products have required extensive time consuming clean-up procedures before quantitating NDEIA. We have found the clean-up procedure developed for cocamide DEA can be applied to a finished product. Figures 5 and 6 illustrate a typical separation and quantitation for NDE1A using the two-column LC technique. The initial separation of NDE1A in a TEA based sunscreen lotion is shown in Figure 5. After the Radial Pak B collection, the interfering peaks were separated, allowing NDEIA quantitation on Radial Pak A: Figure 6. The Radial Pak B clean-up procedure and quantitation on Radial Pak A has proven to be applicable to raw materials and/or finished products.

250 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS INJECTION POINT NDE1A AREA SPIKED INJECTION POINT NDE1A AREA UNSPIKED Figure 4. Cocamide DEA analyzed for NDEIA using a RCSS. CONCLUSION This report has reviewed the development of HPLC methodology for the analysis of nitrosamines from several raw materials, derived from di- and triethanolamine. Both normal and reverse phase LC separations have been applied to isolating and quantitating NDE1A in the cosmetic raw materials. The same techniques have been successfully applied to a finished product to isolate NDE1A from the sample matrix and to subsequently quantkate the isolated nitrosamine. The approach presented here offers viable alternatives for the analysis of polar nitrosamines in cosmetic raw materials and finish•ed products. These techniques are applicable to samples which are readily soluble in water or water/alcohol mixtures. The HPLC/UV methods provide for direct injection of the sample, eliminating extensive sample clean-up and recovery studies. The statistical data demonstrates that