RESUMO
A rapid sample treatment procedure for the gas chromatography-tandem mass spectrometry (GC-MS) determination of 19-nortestosterone (19-NT) in animal tissues has been developed. In our optimized procedures, enzymatic hydrolysis with ß-glucuronidase from Escherichia coli was performed in an acetate buffer (pH 5.2, 0.2 mol/L). Next, the homogenate was mixed with methanol and heated at 60 °C for 15 min, then placed in an ice-bath at -18 °C for 2 h. After liquid-liquid extraction with n-hexane, the analytes were subjected to a normal-phase solid phase extraction (SPE) C18 cartridge for clean-up. The dried organic extracts were derivatized with heptafluorobutyric anhydride (HFBA), and then the products were injected into GC-MS. Using electron impact mass spectrometry (EI-MS) with positive chemical ionization (PCI), four diagnostic ions (m/z 666, 453, 318, and 306) were determined. A standard calibration curve over the concentration range of 1-20 ng/g was reached, with Y=467084X-68354 (R²=0.9997) for 19-NT, and the detection limit was 0.3 ng. When applied to spiked samples collected from bovine and ovine, the recoveries ranged from 63% to 101% with relative standard deviation (RSD) between 2.7% and 8.9%. The procedure is a highly efficient, sensitive, and more economical method which offers considerable potential to resolve cases of suspected nandrolone doping in husbandry animals.
Assuntos
Resíduos de Drogas/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Carne/análise , Nandrolona/análise , Espectrometria de Massas em Tandem/métodos , Animais , Bovinos , Nandrolona/isolamento & purificação , Ovinos , Extração em Fase SólidaRESUMO
4-Ene-3-ketosteroids and 17-ketosteroids were quantitatively transformed into the corresponding hydrazones using Girard P and T reagents, respectively. The positively charged derivatives were separated by capillary electrophoresis. The spectrophotometric characteristics of the derivatives permitted their sensitive detection in the 230-280 nm range. The steroids investigated included nortestosterone and its phenylpropionate, norethisterone and its oenanthate, d,l-norgestrel, dehydroepiandrosterone, androstenedione and ethisterone.
Assuntos
Cetosteroides/isolamento & purificação , Androstenodiona/análogos & derivados , Androstenodiona/análise , Androstenodiona/isolamento & purificação , Betaína/análogos & derivados , Betaína/química , Desidroepiandrosterona/análogos & derivados , Desidroepiandrosterona/análise , Desidroepiandrosterona/isolamento & purificação , Eletroforese Capilar , Etisterona/análogos & derivados , Etisterona/análise , Etisterona/isolamento & purificação , Indicadores e Reagentes/química , Cetosteroides/análise , Nandrolona/análogos & derivados , Nandrolona/análise , Nandrolona/isolamento & purificação , Noretindrona/análogos & derivados , Noretindrona/análise , Noretindrona/isolamento & purificação , Norgestrel/análogos & derivados , Norgestrel/análise , Norgestrel/isolamento & purificação , Espectrofotometria UltravioletaRESUMO
In answer to the mandatory control of the illegal use of anabolizing agents in meat-producing animals imposed by the EEC in farms, a method of analysis of faeces involving high performance liquid chromatography (HPLC) and radioimmunoassay (RIA) has been described. Four HPLC fractions were collected and submitted to corresponding RIA: 17 beta- and 17 alpha-trenbolone, 17 beta-nortestosterone, 17 alpha-nortestosterone and 17 alpha-methyltestosterone. The mean extraction and purification yield was estimated at 44 +/- 7% using tritiated 17 alpha-methyltestosterone as internal standard. Detection limits of the 3 hormones were estimated at 0.2-0.3 ng/g of faeces. About 50 samples can be analysed per week by this method.