title: Gas chromatography with tandem differential mobility spectrometry of fatty acid alkyl esters and the selective detection of methyl linolenate in biodiesels by dual-stage ion filtering.
abstract: Alkyl esters of fatty acids (FAAEs) with carbon numbers from 8 to 20 formed protonated monomers and proton bound dimers through atmospheric pressure chemical ionization reactions and these gas ions were characterized for their field dependent mobility coefficients using differential mobility spectrometry (DMS). Separation of ion peaks with a vapor modifier was achieved for ions with masses of 317-1033 Da though the differences in these coefficients and the resolution of ion peaks decreased proportionally with increased ion mass. Differences in dispersion curves were sufficient to isolate ions from specific FAAEs in the effluent of a gas chromatograph by dual stage ion filtering using a tandem DMS detector. Methyl linolenate was isolated from nearby eluting methyl oleate, methyl stearate and methyl linoleate within analysis times of 10s without measureable complications from charge suppression in the ion source or leakage in filtering of ions with close proximity of dispersion behavior.
authors.affiliation: Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM 88003, USA.
authors.forename: D
authors.initials: D
authors.lastname: Pasupuleti
authors.affiliation: Department of Chemistry and Biochemistry, Seattle Pacific University, Seattle, WA 98119, USA.
authors.forename: K
authors.initials: K
authors.lastname: Pierce
authors.affiliation: Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM 88003, USA. Electronic address: geiceman@nmsu.edu.
authors.forename: G A
authors.initials: GA
authors.lastname: Eiceman
mesh_terms: D056804:Biofuels / Q000032:analysis*; D002849:Chromatography, Gas / Q000379:methods; D004952:Esters; D005227:Fatty Acids / Q000032:analysis*; D005742:Gasoline / Q000032:analysis; D008042:Linolenic Acids / Q000032:analysis; D013057:Spectrum Analysis
chemical_list: D056804:Biofuels; D004952:Esters; D005227:Fatty Acids; D005742:Gasoline; D008042:Linolenic Acids; C047376:methyl linolenate
keywords: Detector; Dual stage ion filtering; Fatty acid methyl esters; Methyl linolenate; Tandem differential mobility spectrometry