Analysis of 19-nortestosterone residue in animal tissues by ion-trap gas chromatography-tandem mass spectrometry

• Published in: Journal of Zhejiang University. B. Science Vol. 12; no. 6; pp. 460 - 467
• Main Authors: Jiang, Jin-qing, Zhang, Lei, Li, Guang-ling, Zhang, Hai-tang, Yang, Xue-feng, Liu, Jun-wei, Li, Ren-feng, Wang, Zi-liang, Wang, Jian-hua
• Format: Journal Article
• Language: English
• Published: Heidelberg SP Zhejiang University Press 01.06.2011; Springer Nature B.V; Zhejiang University Press
• Subjects: Animals; Biomedical and Life Sciences; Biomedicine; Cattle; Drug Residues - analysis; Gas Chromatography-Mass Spectrometry - methods; Meat - analysis; Nandrolone - analysis; Nandrolone - isolation & purification; Sheep; Solid Phase Extraction; Tandem Mass Spectrometry - methods; 19-Nortestosterone (19-NT); Animal tissues; Gas chromatography-tandem mass spectrometry (GC-MS); S859
• ISSN: 1673-1581; 1862-1783
• DOI: 10.1631/jzus.B1000301

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 β-glucuronidase from Escherichia coliwas performed in an acetate buffer （pH 5.2, 0.2 mol/L） Next, the homogenate was mixed with methanol and heated at 60℃ for 15 min, then placed in an ice-bath at -18℃ for 2 h. After liquid-liquid extraction with n-hexane, the analytes were subjected to a normal-phase solid phase ex- traction （SPE） C18 cartridge for clean-up. The dded organic extracts were derivatized with heptafluorobutydc anhydride （HFBA）, and then the products were injected into GC-MS. Using electron impact mass spectrometry （El-MS） with positive chemical ionization （PCI）, four diagnostic ions （mlz 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 （R^2=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.