DIRECT DETERMINATION OF ACID DISTRIBUTIONS IN CRUDES AND CRUDE FRACTIONS

摘要

A method for the direct determination of the acid distribution in petroleum crude oil and crude oil fractions by chlorine negative ion chemical ionization mass spectrometry is disclosed. The crude oil or crude oil fraction is introduced into a mass spectrometer followed by the introduction of a chlorinated reagent capable of producing chloride anions that can react with the acid compounds of the crude oil or crude oil fractions. The mass spectrometer is operated in negative ion mode to selectively detect negatively charged chlorinated adduct ion species. Mass spectra, such as represeted on Figure 3A, are obtained, from which adduct ions are selected. Peaks from resulting mass sub-spectra are identifed, from which the acid species are quantified, as demonstrated in Figure 3B.