柱前衍生-高效液相色谱法测定牛筋中阿维菌素和伊维菌素

HPLC Determination of Avermectin and Ivermectin in Beef Tendon with Precolumn Derivatization

牛筋样品经乙腈提取,用C18固相萃取柱净化,净化液经N-甲基咪唑和三氟乙酸酐的乙腈溶液在室温下进行衍生化,所得阿维菌素和伊维菌素衍生物用高效液相色谱法分析。选用C18色谱柱(4.6mm×150mm,5μm)为固定相,以乙腈-水(97+3)溶液为流动相进行淋洗,于激发波长365nm和发射波长470nm处进行荧光检测。阿维菌素和伊维菌素衍生物的色谱峰面积与其质量分数分别在5～100ng.g-1和10～100ng.g-1范围内具有线性关系,检出限(3S/N)分别为2.5ng.g-1和4.0ng.g-1。在3个浓度水平下做加标回收试验,所得阿维菌素和伊维菌素的回收率在81.6%～101.0%和101.5%～102.4%之间,相对标准偏差(n=6)均不大于2.0%。

The sample of beef tendon was extracted with acetonitrile,and the extract obtained was purified by passing through C18 SPE column.The purified solution was derivatized with N-methylimidazole and trifluoroacetic anhydride（dissolved in acetonitrile） at room temperature.The derivatized product of avermectin（AVM） and ivermectin（IVM） was used for HPLC determination with fluorescence detection using C18 chromatographic column（4.6 mm×150 mm,5 μm） as stationary phase and mixtures of acetonitrile and H2O（97＋3） as mobile phase.Linear relationships were found between values of fluorescence intensity and mass fraction of AVM in the range of 5-100 ng·g-1 and IVM 10-100 ng·g-1 as measured at wavelengths of 365 nm（λex） and 470 nm（λem）.Values of detection limit（3S/N） of AVM and IVM found were 2.5 ng·g-1 and 4.0 ng·g-1 respectively.Tests for recovery were performed by standard addition method at 3 concentration levels for 6 parallel determinations;results of recovery found were in the range of 81.6%-101.0% for AVM and 101.5%-102.4% for IVM,with RSD′s ≤2.0%.