title: Separation and determination of 2,4-D, dicamba and 2,4,5-T in tobacco by nonaqueous capillary electrophoresis.
abstract: A practical method for residue analysis of 2,4-D, dicamba and 2,4,5-T in baked tobacco leaves has been developed using nonaqueous CE (NACE). The herbicide residues of 2,4-D, dicamba and 2,4,5-T in tobaccos were extracted by ultrasonication with ethyl acetate, followed by a cleanup procedure with gel permeation chromatography. The separation of 2,4-D, dicamba and 2,4,5-T by NACE was optimized based on orthogonal experiment design with four factors at three levels. The optimal NACE condition was established with the running buffer of 40.0 mmol/L ammonium acetate in 90% CH3CN (apparent pH 10.2), and the applied voltage of -25 kV over a capillary of 50 microm id x 46 cm (37.5 cm to the detector window), which gave a baseline separation of 2,4-D, dicamba and 2,4,5-T within 15 min. The LOD were ca. 0.4-0.6 microg/mL for the three herbicides, whereas the overall recovery ranged from 80.8 to 84.1%. The proposed method has been successfully applied to measure 300 real tobacco samples, and the residue profiles of the three herbicides in tobacco samples were obtained and evaluated.
authors.affiliation: Chemistry Department, Key Laboratory of Chemical Biology and Organic Chemistry of Henan, Zhengzhou University, Zhengzhou, PR China.
authors.forename: Hongxia
authors.initials: H
authors.lastname: Liu
authors.forename: Juanmei
authors.initials: J
authors.lastname: Song
authors.forename: Po
authors.initials: P
authors.lastname: Han
authors.forename: Yongbo
authors.initials: Y
authors.lastname: Li
authors.forename: Shusheng
authors.initials: S
authors.lastname: Zhang
authors.forename: Huimin
authors.initials: H
authors.lastname: Liu
authors.forename: Yangjie
authors.initials: Y
authors.lastname: Wu
mesh_terms: D003996:Dicamba / Q000032:analysis*; D019075:Electrophoresis, Capillary / Q000379:methods*; D006540:Herbicides / Q000032:analysis*; D006801:Humans; D015394:Molecular Structure; D018515:Plant Leaves / Q000737:chemistry*; D014026:Nicotiana / Q000033:anatomy & histology / Q000737:chemistry*
chemical_list: D006540:Herbicides; D003996:Dicamba