title: Quantification of trace fatty acid methyl esters in diesel fuel by using multidimensional gas chromatography with electron and chemical ionization mass spectrometry.
abstract: Measurement of contamination of marine and naval diesel fuels (arising from product mixing or adulteration) with biodiesel or fatty acid methyl esters can be problematic, especially at very low levels. A suitable solution for this task for trace amounts of individual fatty acid methyl esters with resolution and quantification can be achieved by using a multidimensional gas chromatographic approach with electron and chemical ionization mass spectrometric detection. A unique column set comprising a 100 m methyl-siloxane nonpolar first dimension column and high-temperature ionic liquid column in the second dimension enabled identification of individual fatty acid methyl esters at below the lowest concentrations required to be reported in a diesel fuel matrix. Detection limits for individual fatty acid methyl esters compounds ranged from 0.5 to 5.0 mg/L, with excellent linearity up to 5000 mg/L and repeatability of the method from 1.3 to 3.2%. The method was applied to the analysis of diesel fuel samples with suspected biodiesel contamination. Contamination at 568 mg/L was calculated for an unknown sample and interpretation of the results permitted the determination of a likely source of the contamination.
authors.affiliation: Defence Science and Technology Group, Fishermans Bend, Victoria, Australia.|Australian Centre for Research on Separation Science, School of Chemistry, Monash University, Clayton, Victoria, Australia.
authors.forename: R L
authors.initials: RL
authors.lastname: Webster
authors.affiliation: Defence Science and Technology Group, Fishermans Bend, Victoria, Australia.|School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University, Melbourne, Victoria, Australia.
authors.forename: P M
authors.initials: PM
authors.lastname: Rawson
authors.affiliation: Defence Science and Technology Group, Fishermans Bend, Victoria, Australia.
authors.forename: D J
authors.initials: DJ
authors.lastname: Evans
authors.affiliation: Australian Centre for Research on Separation Science, School of Chemistry, Monash University, Clayton, Victoria, Australia.
authors.forename: P J
authors.initials: PJ
authors.lastname: Marriott
keywords: Biodiesel; Chemical Ionization; Fatty acid methyl esters; Fuel contamination; Multidimensional chromatography