Simultaneous determination of thyreostatic residues in animal tissues by matrix solid-phase dispersion and gas chromatography–mass spectrometry

• Published in: Journal of Chromatography A 2005-05, Vol.1074 (1), p.1-7
• Main Authors: Zhang, Lei, Liu, Yuan, Xie, Meng-Xia, Qiu, Yue-Ming
• Format: Article
• Language: English
• Subjects: Acetamides; Analytical chemistry; Animal productions; Animal tissues; Animals; Antithyroid Agents - analysis; Antithyroid Agents - isolation & purification; Biological and medical sciences; Chemistry; Chromatographic methods and physical methods associated with chromatography; Derivatization; drug residues; Exact sciences and technology; Fluoroacetates; Fluorobenzenes; food analysis; food contamination; Fundamental and applied biological sciences. Psychology; Gas chromatographic methods; gas chromatography; Gas Chromatography-Mass Spectrometry - methods; Gas chromatography–mass spectrometry; mass spectrometry; Matrix solid-phase dispersion; Methimazole - isolation & purification; Methylthiouracil - isolation & purification; Propylthiouracil - isolation & purification; Reproducibility of Results; Sensitivity and Specificity; Silica Gel; Silicon Dioxide; Swine; Terrestrial animal productions; thiocarbamide derivatives; Thiouracil - isolation & purification; thyreostatic drugs; Thyreostats; Trimethylsilyl Compounds; Vertebrates
• ISSN: 0021-9673
• DOI: 10.1016/j.chroma.2005.03.086

A method for determination of thyreostatic residues in animal tissues by matrix solid-phase dispersion (MSPD) and gas chromatography-mass spectrometry in selected ion detection mode was developed. Thyreostatic compounds in different matrices were extracted and purified by combination of MSPD and subsequent solid-phase extraction. Silica gel was selected as the solid support of both procedures and the conditions of the procedures were optimized. Thyreostats were derivatized with pentafluorobenzylbromide (PFBBr) in strong basic medium and then with N-methyl- N-(trimethylsilyl)-trifluoroacetamide (MSTFA), which can improve the yields of derivatization for thyreostats, the repeatability, and therefore the limits of detection (LOD) of thyreostats. The limits of detection reached 10 μg/kg (2-thiouracil, 6-methyl-2-thiouracil and 6-propyl-2-thiouracil), 20 μg/kg (6-phenyl-2-thiouracil) and 50 μg/kg (tapazole) with high recoveries (more than 70% for most of thyreostats) and relative standard deviations between 4.5% and 8.7%.