The accurate determination of C_0-C_3 alkylphenol concentrations in crude oils

摘要

Accurate determination of the concentrations of volatile and semi-volatile phenols in oils is required to reliably quantify the solute levels that are likely to be loaded into oilfield production waters following partition redistribution. We show, from a gas chromatography-mass spectrometry analysis of a North Sea crude oil, that significantly different concentration data for several C_0-C_3 alkylphenols may be obtained, depending upon whether the response of the fragmentation ion or the molecular ion is used, and whether the data are corrected for the relative response factor (RRF) of individual phenols. We also show how a comparison of concentration data for individual phenols obtained both with and without RRF correction can enable the recognition of co-elution. The accurate quantification of phenols in oils can be used to predict more effectively the requirement for production water-treatment facilities and can provide more reliable inventories of these toxic compounds discharged into the environment. The oil-water partition coefficient of p-cresol increases in crude oils with increasing nitrogen, sulfur, and oxygen-containing (NSO)-compounds. The occurrence of high phenols concentrations and relatively low NSO contents in some condensates may present particular problems in water treatment and disposal.