GB/T 22338-2008 English PDF (GBT22338-2008)

This Standard specifies the methods of gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry/mass spectrometry to determine the multi-residues of chloramphenicol in animal-original food. This Standard is applicable to the qualitative confirmation and quantitative determination of chloramphenicol, florfenicol and thiamphenicol residues in aquatic products, livestock and poultry products and livestock and poultry by-products. 2 Gas chromatography-mass spectrometry 2.1 Principle The sample is extracted by ethyl acetate. It is distributed and purified by 4% sodium chloride solution and n-hexane solution. After purification by Florisil column, take toluene as the reaction medium. Use N,O bis(trimethylsilyl)trifluoroacetamide-trimethylchlorosilane (BSTFA+TMCS, 99+1) to silanize at 70¡ãC. Use gas chromatography/negative chemical ionization source mass spectrometry to determine. Use internal standard working curve method for quantification. 2.2 Reagents and materials Unless otherwise stated, it shall only use the confirmed analytically-pure reagents and secondary deionized water or water of equivalent purity in the analysis. 2.2.1 Methanol: Chromatographically pure. 2.2.2 Toluene: Pesticide residue level. 2.2.3 N-hexane: Pesticide residue level. 2.2.4 Ethyl acetate. 2.2.5 Ether. 2.2.6 Sodium chloride. 2.2.7 Chloramphenicol (CAP), florfenicol (FF), thiamphenicol (TAP) standard material: GB/T 22338-2008 www.ChineseStandard.net ? Buy True-PDF ? Auto-delivery. Page 5 of 21 purity is ¡Ý99%. 2.2.8 Meta-nitro chloramphenicol (m-CAP) standard material: purity is ¡Ý99%. 2.2.9 Sodium chloride solution (4%): Weigh an appropriate amount of sodium chloride with water to prepare a 4% sodium chloride solution. Store at room temperature. It can be used for 1 week