Identification of a recovered oil is determined by comparison with known oils, selected because of their possible relationship to the particular recovered oil. The known oils are collected from suspected sources. Samples of such known oils must be collected and submitted along with the unknown for analysis. At present, identification of the source of an unknown oil by itself cannot be made (for example, from a library of known oils).

The use of a flame-photometric detector in addition to the flame-ionization detector provides a second, independent profile of the same oil, that is, significantly more information is available from a single analysis with dual detection.

Many close similarities (within uncertainties of sampling and analysis) will be needed to establish identity beyond a reasonable doubt. The analyses described will distinguish many, but not all samples. For cases in which this method does not clearly identify a pair of samples, and for important cases where additional comparisons are needed to strengthen conclusions, other analyses will be required (refer to Practice D 3415). In particular, Practice D 5739 is useful for such cases.

1.1 This test method covers the comparison of petroleum oils recovered from water or beaches with oils from suspect sources by means of gas chromatography (1, 2, 3). Such oils include distillate fuel, lubricating oil, and crude oil. The test method described is for capillary column analyses using either single detection (flame ionization) or dual detection (flame ionization and flame photometric) for sulfur containing species.

1.2 This test method provides high resolution for critical examination of fine structure that is resistant to weathering. The flame-photometric detection for sulfur components is an adjunct, not a substitute, for flame-ionization detection in the identification of waterborne petroleum oils (). For this reason, flame photometric detection is optional.

This standard does not purport to address the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.