This test method is used to determine the composition of fatty acid alkyl hydrocarbon chains in an oil and can be used to discriminate characteristic ratios for carbon chain length, saturated from unsaturated chains, as well as polyunsaturated chains. The method is a compositional mass balance determination which can provide information to discriminate soybean, canola, camelina, and other common vegetable oils and animal fats. This analysis may also support RINS validation by assuring qualified feedstocks are used.