Identification and Quantification of Hydrocarbon Products in Effluents.

Abstract : This report documents interim results of a study to (1) investigate the capability of infrared (IR) spectroscopy for the identification of specific hydrocarbon products in effluents from washracks and other vehicle serivce operations at Army installations, and (2) make a comparative evaluation of the Environmental Protection Agency's (EPA) gravimetric (STORET 00556) and IR (STORET 00560) methods of quantifying 'total hydrocarbons' in wastewater. Results have shown that IR spectroscopy can provide a basis for the identification of hydrocarbon products for which reference samples are available. In the initial phase of the work, a scheme of sequential discriminant analysis and pattern recognition was used with reference to a file of military specification (MIL SPEC) hydrocarbon products used in servicing wheel- and track-type Army vehicles. The complexity of IR data reduction was shown to increase rapidly with the number of hydrocarbon products present in a given sample -- a result of a similarity in the hydrocarbon components' molecular structure. The use of gas-liquid chromatography (GLC) in conjunction with IR spectroscopy provided additional discrimination and simplified data reduction. A comparative investigation of the gravimetric vs IR methods for the quantification of 'total hydrocarbons' in wastewater showed that the IR method was capable of higher precision than the gravimetric method at hydrocarbon concentrations less than 10 mg/l, and could provide information on chemical composition and consequently the origin of the hydrocarbon product.