title: Determination of carbofuran in surface water and biological tissue by sol-gel immunoaffinity extraction and on-line preconcentration/HPLC/UV analysis.
abstract: A selective and simple analytical method for the trace level determination of carbofuran in complex environmental and biological samples was developed based on immunoaffinity extraction (IAE) followed by on-line preconcentration and HPLC/UV analysis of the purified extract. The immunosorbent for IAE was prepared by sol-gel encapsulation of monoclonal anti-carbofuran antibodies, and was fully characterized for capacity, repeatability, binding strength, binding kinetics and cross-reactivity. Method performance was evaluated with two different types of difficult samples: dam water and methanolic extracts of epithelial cervical-uterine tissue. Linear behavior and quantitative recoveries were obtained from the analysis of samples spiked with carbofuran at 0.2-4 ng/mL (dam water, 50 mL samples) and 10-40 ng/mL (biological tissue extract, 2 mL samples). RSD (n=7) and detection limits were, respectively, 10.1% (spike 0.40 ng/mL) and 0.13 ng/mL for dam water; 8.5% (spike 20 ng/mL) and 5 ng/mL for the biological tissue extract. The excellent sample purification achieved with the IAE column allows precise and accurate determination of carbofuran in complex matrices, even when using non-selective UV detection in the chromatographic analysis.
authors.affiliation: Facultad de Química, Departamento de Química Analítica, Universidad Nacional Autónoma de México, 04510 México, D.F., Mexico. luzelena@unam.mx
authors.forename: Luz E
authors.initials: LE
authors.lastname: Vera-Avila
authors.forename: Bani P
authors.initials: BP
authors.lastname: Márquez-Lira
authors.forename: Marcos
authors.initials: M
authors.lastname: Villanueva
authors.forename: Rosario
authors.initials: R
authors.lastname: Covarrubias
authors.forename: Gustavo
authors.initials: G
authors.lastname: Zelada
authors.forename: Valérie
authors.initials: V
authors.lastname: Thibert
mesh_terms: D000327:Adsorption; D000911:Antibodies, Monoclonal / Q000737:chemistry; D002138:Calibration; D002235:Carbofuran / Q000032:analysis*; D002584:Cervix Uteri / Q000737:chemistry*; D005591:Chemical Fractionation / Q000379:methods*; D002846:Chromatography, Affinity / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D004848:Epithelium / Q000737:chemistry; D005260:Female; D005782:Gels; D006801:Humans; D055767:Immobilized Proteins / Q000737:chemistry; D007306:Insecticides / Q000032:analysis; D057230:Limit of Detection; D000432:Methanol / Q000737:chemistry; D044367:Phase Transition; D014867:Water; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D000911:Antibodies, Monoclonal; D005782:Gels; D055767:Immobilized Proteins; D007306:Insecticides; D014874:Water Pollutants, Chemical; D014867:Water; D002235:Carbofuran; D000432:Methanol