二甲硝咪唑在鸡蛋中的残留研究

Study on the Detection of Dimetridazole Residue and Its Major Metabolite in Eggs

本文建立了高效液相色谱法 (HPLC)测定鸡蛋中二甲硝咪唑 (DMZ)残留水平的方法。产蛋鸡内服 50 mg/kgbw和 200 mg/kgbw、肌注 50 mg/kgbw二甲硝咪唑，连用 5 d。测定了用药期间及停药后蛋清及蛋黄中 DMZ及其羟基代谢物 (DMZOH)的含量，方法检测限为 0.01μ g/g。鸡蛋中 DMZ及其 DMZOH的含量在休药 6～ 7 d时低于检测水平。排泄到蛋黄中的二甲硝咪唑及其羟基代谢物约占鸡蛋中残留总量的 56％，蛋清约占 44％。

A study was conducted to minotor the elimination of dimetridazole(DMZ) and its major metabolite 2－ hydroxymethy－ 1－ methy1－ 5－ nitroimidazole(DMZOH) in eggs,using a liquid chromatographic method with ultrovolet detector.The drug was extracted from eggs with 5％ isopropanol in the trichloromathane solution ,and the extract was concentrated to dry under 50℃ in the nitrogen gas,the residue was dissolived in methanol.LC analysis was carried out on a novapak C18 column(5um,3.9× 220 mm) by 0.0075 mol/L NaH2PO4:methanol (4∶ 1,v/v),and detected at UV 320 nm.Average recoveries from eggs at level of 0.05,0.5,2.0μ g/g were ranged from 92.63％～ 96.58％ ,83.54％～ 85.96％ respectively.The detection limit was 0.01μ g/g. The withdrow time in eggs was 6～ 7 day at 0.01μ g/g level,egg yolk long than albumen,the concentration of DMZ and DMZOH in yolk high than the albumen.The total amounts of DMZ and DMZOH excreted into eggs after oral dosage at 50 and 250 mg/kgbw were 1.29％ and 1.36％ of the total dose,respectively.After intramuscular treatment,about 1.59％ of total dose was excreted into eggs.