title: Quantitative gas chromatographic method for the analysis of cis-9, trans-11 and trans-10, cis-12 isomers of the conjugated linoleic acid in liver.
abstract: A quantitative GC method for conjugated linoleic acid (CLA) isomers of physiological significance (cis-9, trans-11 CLA and trans-10, cis-12 CLA) as non-esterified fatty acids (NEFA) or triacylglycerols (TAG) was developed. Furthermore, the effect of the internal standard addition point (sample or fat extract) was studied. Response linearity, recovery and precision assays, detection and quantification limits were determined. Linearity was demonstrated over a range from 0.1 to 10 microg/mL. When CLA isomers were present as NEFA, the recovery significantly decreased (P< or =0.05) from 76% to 27.1% (cis-9, trans-11 CLA) and 28.5% (trans-10, cis-12 CLA) when the standards were added to the fat extract or to the initial tissue, respectively. As an application, liver samples from hamsters fed a diet supplemented with both CLA isomers were analyzed. The CLA isomers in liver samples were detected with reasonable reproducibility.
authors.affiliation: Department of Nutrition and Food Science, University of the Basque Country, Paseo de la Universidad 7, Vitoria, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Zabala
authors.forename: M P
authors.initials: MP
authors.lastname: Portillo
authors.forename: V
authors.initials: V
authors.lastname: Navarro
authors.forename: M T
authors.initials: MT
authors.lastname: Macarulla
authors.forename: L J R
authors.initials: LJ
authors.lastname: Barron
authors.forename: A
authors.initials: A
authors.lastname: Fernández-Quintela
mesh_terms: D000818:Animals; D002849:Chromatography, Gas / Q000379:methods*; D006224:Cricetinae; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage / Q000378:metabolism; D044243:Linoleic Acids, Conjugated / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D008099:Liver / Q000737:chemistry* / Q000378:metabolism; D008297:Male; D013237:Stereoisomerism
chemical_list: D004042:Dietary Fats, Unsaturated; D044243:Linoleic Acids, Conjugated; C503589:cis-9, trans-11-conjugated linoleic acid; C496197:trans-10,cis-12-conjugated linoleic acid