Hydrocarbons and polychlorinated biphenyls from the unsaponifiable fraction of anhydrous milk fat.

Using a combination of gas-liquid chromatography and mass spectrometry, the presence of 39 aliphatic hydrocarbons was firmly established in the unsaponifiable fraction of anhydrous milk fat. The hydrocarbons were the C(14) to C(27) and the C(29) to C(31) straight-chain paraffins, their monoolefin analogs, and the C(25) to C(29) branched alkanes. Phytene (3,7,11,15-tetramethyl-n-hexadec-2-ene), identified for the first time in milk fat, was isolated and identified by high-resolution mass spectrometry and infrared analysis. The total hydrocarbon content amounted to 30 ppm of the milk fat. Polychlorinated biphenyls also were detected in trace amounts in the area of the chromatogram between the C(18) and the C(23) hydrocarbons.