IDENTIFICATION OF CRUDE AND LUBRICATING OILS BY LOW TEMPERATURE LUMINESCENCE

Luminescence and phosphorescence of crude and lubricating oil dissolved in methylcyclohexane at 77 degree K were measured, and the effects of weathering on these oils for periods equal to 1 wk were examined. Instrumentation included Baird-Atomic Fluorispec, Aminco-Bowman, and Farrand Mark I spectrophotometers. Corrected and uncorrected luminescence and luminescence excitation spectra taken under instrumental conditions are compared. The advantages of corrected excitation spectra are discussed. Optimum instrumental settings for each instrument are described. The low temperature luminescence method for petroleum oils has been successfully applied to oil spills and to differentiation of natural seeps from closely similar production oils. Temperatures less than 77 degrees K may be used if an appropriate solvent is used and if a cooling system is available. This method also has applications for oils of vegetable and animal origin, synthetic oils from oil shale or coal, and for chlorinated hydrocarbons and other hazardous chemicals.