title: A colorimetric method for determination of γ-glutamyl-S-ethenyl-cysteine in narbon vetch (Vicia narbonensis L.) seeds.
abstract: A new colorimetric method based on the bleaching of the iodoplatinate ion has been developed for fast and easy determination of γ-glutamyl-S-ethenyl-cysteine (GEC) in narbon vetch (Vicia narbonensis L.) seeds. The calibration curve showed a good correlation (r(2)=0.9959) between absorbance and GEC amounts from 5.5 to 33 μg (10-59.78 μmol/L). The limits of detection and quantification were 1.16 and 3.55 μmol/L, respectively, and no significant interferences from other sulfur-containing compounds were observed. The method showed excellent repeatability (relative standard deviation [RSD]=0.28%), reproducibility (RSD=4.4%), and accuracy (94%). Determination of GEC in 20 narbon vetch accessions yielded values that were in agreement with those reported previously using capillary electrophoresis and high-performance liquid chromatography methods. The method could be especially valuable for determination of GEC during the process of production of new low-GEC narbon vetch varieties.
authors.affiliation: Departamento de Cultivos Herbáceos, Centro Agrario de Albaladejito, Junta de Comunidades de Castilla-La Mancha, 16194 Cuenca, Spain. rsanchezv@jccm.es
authors.forename: R
authors.initials: R
authors.lastname: Sánchez-Vioque
authors.forename: M F
authors.initials: MF
authors.lastname: Rodríguez-Conde
authors.forename: J
authors.initials: J
authors.lastname: Vioque
authors.forename: J
authors.initials: J
authors.lastname: Girón-Calle
authors.forename: O
authors.initials: O
authors.lastname: Santana-Méridas
authors.forename: M
authors.initials: M
authors.lastname: De-los-Mozos-Pascual
authors.forename: M E
authors.initials: ME
authors.lastname: Izquierdo-Melero
authors.forename: M
authors.initials: M
authors.lastname: Alaiz
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003124:Colorimetry / Q000379:methods*; D004151:Dipeptides / Q000032:analysis*; D019075:Electrophoresis, Capillary / Q000379:methods; D007454:Iodides / Q000737:chemistry; D057230:Limit of Detection; D017671:Platinum Compounds / Q000737:chemistry; D015203:Reproducibility of Results; D012639:Seeds / Q000737:chemistry*; D031306:Vicia / Q000737:chemistry*
chemical_list: D004151:Dipeptides; D007454:Iodides; D017671:Platinum Compounds; C503744:gamma-glutamyl-S-ethenyl-cysteine; C013575:iodoplatinate