Certain predominant unknown metabolites of aldrin and of dieldrin, previously reported in the urine of rats on diets containing these pesticides, have been characterized by mass, infrared, and Raman spectrometric examination. By interpretation of all the evidence adduced, the structure of the isomeric metabolites of aldrin and dieldrin. respectively, could be postulated. The metabolites appear to be almost identical, the minor spectrometric differences being attributed to possible alternative exo- or endo-orientations of an epoxide ring.

An ultraviolet absorption test to limit the total polycyclic aromatic hydrocarbon content in petroleum waxes has been developed. The procedure consists of extraction of a solution of melted wax in an aliphatic solvent with a dimethyl sulfoxide-phosphoric acid mixture, followed, if necessary, by chromatography on a magnesia-Celite column. Recoveries of representative polycyclic aromatic hydrocarbons, added at a level of 12.5 μg to 25 g samples (0.5 ppm) of wax, ranged from 64 to 93% after the extraction part of the procedure, and from 44 to 85% after the column chromatographic part of the method. The variations in the recoveries may be attributed to the differences in the partition coefficients of the hydrocarbons between the aliphatic solvent and the dimethyl sulfoxide-phosphoric acid extraction mixture, plus the tendency of some of the compounds to be oxidized during the chromatographic part of the test. The procedure has been applied to the analysis of commercial, refined petroleum waxes, and specifications have been developed to limit the total polycyclic aromatic content of such waxes for food additive use.

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A method for the isolation and determination of polynuclear hydrocarbons in paraffin wax has been developed in which polynuclear compounds are extracted from the wax by diluting a melted wax solution with an aliphatic solvent and extracting the resulting solution with dimethyl sulfoxide. Paper chromatographic techniques are used to separate the compounds from the background material extracted from the wax. The hydrocarbons are rechromatographed until their ultraviolet absorption spectra are comparable to those obtained for pure compounds. Recoveries of 19 polynuclear hydrocarbons added to 100 g samples of paraffin wax at levels of 0.1 ppm or less ranged from 62 to 96%. Recoveries of benzo(a)pyrene and dibenz(a, h) anthracene added to 100 g or 500 g of wax at levels as low as 0.02 ppm or 0.005 ppm, respectively, were in the range 90—100%. The variations in the recoveries are apparently caused by differences in the partition coefficients of the hydrocarbons between the aliphatic solvent and dimethyl sulfoxide and at lower levels by the tendency of some of the compounds to be oxidized. The method has been utilized for the determination of polynuclear hydrocarbons in commercial waxes.