title: Determination of amitraz in canine plasma by solid-phase microextraction-gas chromatography with thermionic specific detection.
abstract: A simple and rapid analytical method is presented for the determination of amitraz in canine plasma samples using solid-phase microextraction (SPME) and gas chromatography with thermionic specific detection (GC-TSD). The best conditions for the SPME procedure were: direct extraction on a polydimethlysiloxane (PDMS) fiber with 100-microm film thickness; 400 &microl of sample plasma matrix modified with 4 ml sodium borate solution (0.01 mol l(-1), pH 6.5); extraction temperature 70 degrees C, with stirring at 2500 rpm for 45 min. The method was linear between 20 and 400 ng ml(-1) with regression coefficients corresponding to 0.998 and coefficient of the variation of the points of the calibration curve lower than 15%. The lowest limit of quantification (LOQ) for amitraz in plasma was 20 ng ml(-1). This LOQ was determined as the lowest concentration on the calibration curve in which the coefficient of variation was lower than 15%. The proposed method was applied to determine amitraz concentrations in canine plasma to look for toxicity after treatment with amitraz in a dipping bath.
authors.affiliation: Department of Pharmaceutical Science, University of Ribeirão Preto, SP, Ribeirão Preto, Brazil.
authors.forename: M E C
authors.initials: ME
authors.lastname: Queiroz
authors.forename: C A A
authors.initials: CA
authors.lastname: Valadão
authors.forename: A
authors.initials: A
authors.lastname: Farias
authors.forename: D
authors.initials: D
authors.lastname: Carvalho
authors.forename: F M
authors.initials: FM
authors.lastname: Lanças
mesh_terms: D000818:Animals; D002138:Calibration; D004285:Dogs; D007302:Insect Repellents / Q000097:blood*; D012680:Sensitivity and Specificity; D014052:Toluidines / Q000097:blood*
chemical_list: D007302:Insect Repellents; D014052:Toluidines; C014983:amitraz