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I. Soc. Cosmet. Chem., 25, 507-514 (September 1974) NMR--A New Instrumental Tool for the Analysis of Cosmetic Ingredients RICHARD KAPLAN, B.S., and STEPHEN F. LAczYNsKI, B.S.* Presented October 9, 1973, Joint Symposium of the Society of Cosmetic Chemists and the Association of O•ficial Analytical Chemists, Washington, D.C. Synopsis-A basic introduction into the theory and quality control applications of a '60 Megahertz NMR Spectrophotometer is given. Quantitative methods for evaluation of IODINE NUMBER, ESTER VALUE, HYDROXYL NUMBER, and MOLES OF ETHOXYLATION on cosmetic raw ingredients are presented. Determination of ALCO- HOL-WATER RATIOS on finished ingredients are shown to comply with a time-consum- ing distillation method. Determinates affecting accuracy and precision in compliance with classical wet chemistry tests for the above are also discussed. INTRODUCTION Basic NMR Theory Many atomic nuclei, in addition to carrying a positive charge, spin about an axis of rotation. These particles because of their charge and movement behave as tiny bar magnets. One such nucleus (the one with which we are most concerned) is the proton, the nucleus of ordinary hydrogen. The hydrogen protons exist in a ground state consisting of two or more in- distinguishable energy levels in the absence of an applied magnetic field. If the nuclei are placed in an external magnetic field, alignment with and against this field occurs. It would appear plausible that the majority would align with the applied magnetic field. Actually, quantum mechanics theory states that only an extremely small portion aligning with the field are in excess. Protons aligning with the field have lower energy and those aligning against the field are said to have higher energy. The Boltzman distribution equation states that in a field of 10,000 Gauss only an excess of 7 out of i million protons are in the lower energy state. This *Avon Products, Inc., Suffern, N.Y. 10901. 5O7