title: Application of coupled-column liquid chromatography combined with post-column photochemically induced fluorimetry derivatization and fluorescence detection to the determination of pyrethroid insecticides in vegetable samples.
abstract: This study reports the first application of coupled-column liquid chromatography-photochemically induced fluorimetry-fluorescence detection (LC-LC-PIF-FD), demonstrating its potential for the quantitative and selective detection of seven pyrethroids in vegetable samples such as cucumber, green bean, tomato and aubergine. An internal surface reversed-phase (ISRP) column coupled to a C18 column for analyte clean-up and determination were used, respectively. In comparison with a C18 column, the ISRP substantially improved the separation between analytes and interferences from the vegetable matrix. The limits of detection ranged from 0.01 to 0.22 microg kg(-1) in the vegetable samples (equivalent to 0.01 and 0.13 microg L(-1) in the extract injected), and limits of determination ranged from 0.56 to 8.33 microg kg(-1) in the vegetable samples (equivalent to 0.34 and 5.00 microg L(-1) in the extract injected). Samples were extracted into dichloromethane to yield mean recoveries at two levels of concentration between 72.8 and 110.0% in all cases. Relative standard deviations were lower than 11%.
authors.affiliation: Department of Analytical Chemistry, University of Almería, La Cañada de San Urbano, 04120, Almería, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Parrilla Vázquez
authors.forename: M D
authors.initials: MD
authors.lastname: Gil García
authors.forename: D
authors.initials: D
authors.lastname: Barranco Martínez
authors.forename: M
authors.initials: M
authors.lastname: Martínez Galera
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods; D005453:Fluorescence; D005470:Fluorometry / Q000379:methods*; D007306:Insecticides / Q000032:analysis*; D008752:Methylene Chloride / Q000737:chemistry; D010777:Photochemistry; D010782:Photolysis; D011722:Pyrethrins / Q000032:analysis*; D012680:Sensitivity and Specificity; D014675:Vegetables / Q000737:chemistry*
chemical_list: D007306:Insecticides; D011722:Pyrethrins; D008752:Methylene Chloride