Screening method for simultaneous detection of elaidic and vaccenic trans fatty acid isomers by capillary zone electrophoresis

A novel screening method for the simultaneous detection of elaidic and vaccenic trans fatty acid isomers by CZE-UV was proposed and applied to brazilian spreadable cheese analysis. Optimized background electrolyte was composed by 10 mmol L−1 heptakis (2, 3, 6-tri-o-methyl)-beta cyclodextrin, 24 mmol L−1 sodium tetraborate buffer solution, 45% methanol and 15% acetonitrile. Sample preparation comprised only a saponification reaction and dilution of sample solution before analysis. The method proved to be simple, environmental friendly and sensitive (LOD calculated for elaidic and vaccenic acid were 0.0163 mmol L−1 and 0.0169 mmol L−1, respectively) and may be used to detect adulteration in dairy products, where the addition of hydrogenated vegetable fat to food is prohibited. [Display omitted] •Separation of elaidic and vaccenic trans fatty acid isomers was carried out for the first time by CE.•The screening method proposed can be suitable to detect adulteration in dairy products.•The optimized method proved to be simple, environmental friendly and sensitive.•A simple sample pretreatment was employed and no derivatization reaction was needed.