Oil Fingerprinting

Cleaning, the removal of unwanted matter, is the beginning of the treatment cycle for metal. The unwanted matter may be carbon smut, welding flux, ink, oxidation products, oil, fingerprints, or other material. Cleaners may be classified as solvent-based or aqueous. Within the aqueous class there are many subclasses, the most important of which are the alkaline cleaners. There are also a variety of ways to apply cleaners. As of the mid-1990s, solvent-based cleaner usage is declining. 

An oil fingerprint is best obtained using a packed column coupled to a flame ionization detector (FID), whilst a capillary column linked to FID will provide the details in the trace to discriminate between peaks for the normal hydrocarbons and those for the isoprenoid. 

Since the authors review on Oil Spill Identification (1,2), a number of significant occurrences have firmly established oil fingerprinting as a valid approach to the identification of spill sources. These include increased understanding of the effects of weathering on oils, continued refinement of various analytical techniques, continued refinement of computer pattern recognition techniques for comparison of oils, the adoption by ASTM of new methods of analysis of waterborne oils (3,4, 5), the establishment of a Central Oil Identification Laboratory (COIL)... 

A major legal aspect is the adoption of standard methods for oil fingerprinting such as the ASTM consensus standards, because it facilitates acceptability of the findings as evidence in court cases. 

Following is a look at the most recent developments in oil spill identification by several of these oil fingerprinting techniques, including sampling and a discussion of an interlaboratory study on the effects of weathering on the capability to match oils. 

Infrared. The use of infrared for oil fingerprinting is well documented (32,33,34,35). The technique has a well-demonstrated capability and is one of the four primary Coast Guard methods (18) that is in operational use by COIL. In addition, it has been tested in the field for over a year in Philadelphia and will shortly begin testing in San Francisco, California, and New York, using relatively inexpensive dual-beam grating instruments. 

F 1-m-P) and Ci-dibenzothiophene distribution index (4- 2-/3- l-m-DBT), the selected PAH isomers for oil fingerprinting studies include 3 isomers each within Cs-naphthalenes... 

Kaufman, R.T. et al. 1997. Characterizing the greater Burgan field use of geoehemistry and oil fingerprinting. Society of Petroleum Engineers, Paper No. 37803. 

Vertrel KCD-9547 is a proprietary azeotrope-like blend of Vertrel XF hydrofluorocarbon with trans-1,2-dichioro-ethylene and cyclopentane. It is ideally suited for use in vapor degreasing equipment to remove light oils, fingerprints, and particulate contaminants. Vertrel KCD-9547 is specially formulated to provide a high degree of compatibility with plastics, elastomers, and other nonferrous metals, such eis in aerospace parts. Vertrel KCD-9547 is nonflammable, has "zero" ozone depletion potential, and heis low global warming potential. It can replace CFC-113,1,1,1 -trichloroethane (1,1,1 -TCA), hydrochlorofluorocarbons (HCFC), and perfluorocarbons (RFC) in many applications. 

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