title: A Rapid Method for Determination of the Main Conjugated Linoleic Acid Precursors (C18:2 n-6 and C18:3 n-3) in Forage by Capillary Zone Electrophoresis with Ultraviolet Detection Using Gas Chromatography with Flame Ionization Detection as a Comparative Method.
abstract: A rapid method has been proposed for determination of the main conjugated linoleic acid precursors such as linoleic (C18:2 n-6) and linolenic (C18:3 n-3) acids in forages by capillary zone electrophoresis (CZE) with direct UV detection at 200 nm. Among the fatty acids found in forages, C18:2 n-6 and C18:3 n-3 have received particular attention due to their roles as precursors for the synthesis of conjugated linoleic acid, a class of health-enhancing compounds that is predominantly found in dairy products. The electrolyte background consisted of 12.0 mmol/L tetraborate buffer (pH 9.2) added to 12.0 mmol/L Brij 35®, 17% acetonitrile, and 33% methanol. Under the optimized conditions, the baseline separation of C18:2 n-6 and C18:3 n-3 was achieved within 4 min. The CZE-UV method was compared to GC with a flame ionization detector, which is the American Oil Chemists' Society (AOCS 996.06) official method for fatty acid analysis. The methods did not show any evidence of significant differences within 95% confidence interval (P>0.05). The CZE-UV method was successfully applied to the analysis of 80 genotypes of Brachiaria ruzizienses clones submitted to a genetic improvement program in agricultural research.
authors.affiliation: Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Juiz de Fora, Cidade Universitária CEP 36036-330, Juiz de Fora, MG, Brazil.
authors.forename: Renata
authors.initials: R
authors.lastname: de Jesus Coelho Castro
authors.forename: Fausto Souza
authors.initials: FS
authors.lastname: Sobrinho
authors.forename: Marco Antônio
authors.initials: MA
authors.lastname: Sundfeld da Gama
authors.forename: Renata
authors.initials: R
authors.lastname: Takabayashi Sato
authors.forename: Larissa
authors.initials: L
authors.lastname: Lavorato Lima
authors.forename: Marcone Augusto
authors.initials: MA
authors.lastname: Leal de Oliveira
mesh_terms: D035201:Brachiaria / Q000737:chemistry* / Q000235:genetics; D002849:Chromatography, Gas / Q000379:methods*; D019075:Electrophoresis, Capillary / Q000379:methods*; D005410:Flame Ionization; D005838:Genotype; D007477:Ions / Q000737:chemistry; D057230:Limit of Detection; D044243:Linoleic Acids, Conjugated / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet; D013997:Time Factors
chemical_list: D007477:Ions; D044243:Linoleic Acids, Conjugated