猪肉中莫西克汀残留高效液相色谱-荧光检测方法的建立

Determination of Moxidectin residue in pork by HPLC-FLD

为方便检测猪肉中莫西克汀残留量,建立了高效液相色谱-荧光检测方法(HPLC-FLD)。样品采用乙腈提取,加水稀释,用三乙胺调节pH,C18固相萃取柱净化,加三氟乙酸酐和N-甲基咪唑衍生化。以乙腈/水为流动相,高效液相色谱-荧光检测法测定,选择激发波长为365nm,发射波长为475nm。在0.01～1.00μg/mL质量浓度范围内,莫西克汀的色谱峰面积与浓度呈线性相关,相关系数大于0.99;添加量为5、50和250ng/g时,平均添加回收率为92.16%～99.39%;日内变异系数为2.8%～4.1%(n=5),日间变异系数为6.4%～8.5%(n=3)。本方法的检测限为2ng/g,定量限为5ng/g。该方法准确、灵敏,可用于猪肉中莫西克汀的残留分析。

A high-performance liquid chromatography-fluorescence detection（HPLC-FLD） method was developed for determination of Moxidectin in pork.The target compound was extracted by acetonitrile,diluted by water and pH was moderate with triethylamine.The solution was purified by C18 Column of solid-phase extraction（SPE）,derived by trifluoroacetic anhydride and N-methylimidazole.Determination was performed by reverse phase HPLC-FLD with acetonitrile and water,with the Excitation spectra of 365 nm and Emission spectra of 475 nm.Between 0.01 and 1.00 μg/mL,the chromatographic peak area of Moxidectin showed linear correlation to their concentration,with the correlation coefficients of 0.99.At the spiked levels of 5、50 and 250 ng/g,recoveries ranged from 92.16% to 99.39%,with the intra-day coefficient variation（CVd） of 2.8%-4.1%（n=5） and inter-day coefficient variation（CVr） was 6.4%-8.5%（n=3）.The limit of detection（LOD） of Moxidectin in pork was 2 ng/g,and the limit of quantitation（LOQ） was 5 ng/g.The method was accurate and sensitive.It could be used for determining the residues of Moxidectin in pork.