180 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table I Recovery of Diazolidinyl Urea in a Variety of Spiked Matrices Sample Dilution (%) % Added • % Recovery Pain-relief gel Burn-relief gel Vitamin E/lanolin lotion Douche Shampoo 2.5 0.01 82 2.5 0.01 88 5.0 0.005 103 5.0 0.02 91 10 0.025 79 5.0 0.025 79 2.5 0.01 95 5.0 0.005 71 5.0 0.01 80 5.0 0.02 80 2.5 0.025 82 10 0.01 68 10 0.01 78 10 0.005 82 10 0.01 78 10 0.02 74 Concentration of spike not adjusted for dilution of sample. Table II Determination of % Diazolidinyl Urea by the Method of Standard Additions in a Variety of Consumer Products Product % Found • Hand lotion 0.35 (n = 6) Burn-relief gel 0.33 (n = 2) Pain-relieving gel 0.28 (n = 6) Shampoo 0.13 (n = 3) Douche 0.16 (n = 2) Values corrected for sample dilution. of hand lotion was prepared as described and analyzed six times (one vial). The average peak area was 287263 -+ 5458 (C.V. = 1.9%). Six samplings of a 5% solution of hand lotion (six vials) gave an average peak area of 289545 -+ 3475 (C.V. = 1.2%). Diazolidinyl urea found. Six samples of the pain-relieving gel were prepared and ana- lyzed. The average diazolidinyl urea found was 0.28% -+ 0.027% (C.V. - 9.6%). Six samples of vitamin E and lanolin hand lotion were prepared. Analysis gave an average % diazolidinyl urea of 0.35% -+ 0.030% (C.V. = 8.6%). In conclusion, a method has been described for the direct determination of diazolidinyl urea in cosmetic formulations. The method provides rapid elution time of the analyte (•4 minutes) and excellent resolution from other detectable formulation components. Also, there is no need for the derivatization/degradation procedures traditionally used for these analyses. CE is rapidly becoming an accepted analytical technique, and this method should prove useful in the determination of diazolidinyl urea. However, there is a very broad range of matrices and components found in cosmetic products. The

DETERMINATION OF DIAZOLIDINYL UREA 181 method was not validated or attempted for all possible matrices that may be encoun- tered. ACKNOWLEDGMENTS The authors are grateful to Dr. William Rosen, Dr. John Merianos, Tim Parsons, and David Steinberg of Sutton Laboratories/ISP for providing the diazolidinyl urea, the consumer samples, and their expert advice and comments. Thanks are also owed to Matthew Benning and Paul Suszczynski of ISP for the HPLC analysis for parabens of some of the formulations. Permission to publish by ISP is gratefully acknowledged. REFERENCES (1) Germall © II Product Brochure (Sutton Laboratories, Chatham, NJ). (2) T. Nash, Colorimetric determination of formaldehyde under mild conditions, Biochem. J., 55, 416- 421 (1953). (3) E. Sawicki, T. R. Hauser, and S. McPherson, Spectrophotometric determination of formaldehyde and formaldehyde-releasing compounds with chromotropic acid, 6-amino-l-naphthol-3-sulfonic acid (J acid) and 6-anilino-1-naphthol-3-sulfonic acid (phenyl J acid), Anal. Chem., 34, 1460-1464 (1962). (4) R. L. Shriner, R. C. Fuson, D. Y. Curtin, and T. C. Morrill, The Systematic Identification of Organic Compounds, 6th ed. (John Wiley & Sons, New York, 1980). (5) H. Engelhardt and R. Klinkner, Determination of free formaldehyde in the presence of donators in cosmetics by HPLC and post-column derivation, Chromatographia, 20(9), 559-565 (1985). (6) W. R. Summers, Characterization of formaldehyde and formaldehyde-releasing preservatives by com- bined reversed-phase cation-exchange high-performance liquid chromatography with postcolumn de- rivatization using Nash's reagent, Anal. Chem., 62, 1397-1402 (1990). (7) A. R. Stack and H. M. Davis, Liquid chromatographic separation and fluorometric determination of quaternium-15 in cosmetics, J. Assoc. Off. Anal. Chem., 67(1), 13-15 (1984). (8) R. J. Geise, N. I. Machnicki, and R. I. Ianniello, Determination of allantoin in cosmetic products by capillary zone electrophoresis, Anal. Lett. 27(1), 183-194 (1994).