Determination of Alkenes in Hydrocarbon Matrices by Acetone Chemical Ionization Mass Spectrometry

Abstract

The use of acetone and acetone-d6 as reagent gases for the selective determination of alkenes in hydrocarbon samples by chemical ionization mass spectrometry (CI MS) is reported. An intense (M + 43)+ or (M + 46)+ adduct ion peak is produced in the acetone or acetone-d6 CI mass spectra of alkenes. The same adduct ion is not observed in the acetone or acetone-d6 CI mass spectra of cycloalkanes. This selective formation of the acetyl adduct can be used to differentiate alkenes from cycloalkanes. The suitability of the method to be used for the analysis of alkenes in hydrocarbon mixtures is demonstrated by the analysis of a whole gasoline sample and its olefin extract. The capabilities of the method for quantitative analysis are illustrated by the analysis of a light gas oil sample.