高级检索

    通过型固相萃取-超高效液相色谱-串联质谱法测定饲料中泰拉霉素的含量

    Determination of Tulathromycin in Feed by Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry with Through Solid Phase Extraction

    • 摘要: 取2.50 g饲料样品置于50 mL离心管中,加入提取溶剂含0.25%(体积分数)甲酸的甲醇溶液 20 mL,振荡15 min,再离心3 min,取上清液置于50 mL离心管中,残渣用20 mL提取溶剂重复提取一次,合并两次上清液,用提取溶剂定容至50 mL,混匀,取2.0 mL溶液过EMR固相萃取小柱(300 mg/3 mL),加入1 mL甲醇淋洗,收集过柱提取液和淋洗液,于50 ℃氮吹干,加入4 mL体积比9∶1的0.1%(体积分数,下同)甲酸溶液-甲醇混合液,涡旋混匀,过0.22 μm有机滤膜,采用超高效液相色谱-串联质谱法(UHPLC-MS/MS)测定滤液中泰拉霉素(以泰拉霉素A计)的含量。以Acquity UPLC BEH C18色谱柱为固定相,以不同体积比的0.1%甲酸溶液-甲醇混合液为流动相进行梯度洗脱,采用电喷雾离子(ESI)源,在正离子(ESI+)扫描模式下进行多反应监测(MRM)模式质谱分析。结果表明,泰拉霉素的质量浓度在0.50~100 μg·L−1内与对应的定量离子对的峰面积呈线性关系,检出限(3S/N)为3.0 μg·kg−1。按照标准加入法进行回收试验,回收率为93.0%~106%,测定值的相对标准偏差(n=5)均小于10%。方法用于分析38个实际饲料样品,泰拉霉素均未检出。

       

      Abstract: The feed sample (2.50 g) was taken and placed in a 50 mL-centrifuge tube. 20 mL of extract solvent methanol solution containing 0.25% (volume fraction) formic acid was added, and the mixture was shaken for 15 min and centrifuged for 3 min. The supernatant was taken and placed in a 50 mL-centrifuge tube. The extraction of the residue was repeated with 20 mL of extract solvent. The two supernatants were combined, and the solution was made its volume up to 50 mL with extract solvent and mixed well. 2.0 mL of the solution was taken and passed through an EMR solid-phase extraction column (300 mg/3 mL), and 1 mL of methanol was added for rinsing. The column extraction solution and the eluent were collected and blown to dryness by nitrogen at 50 ℃. 4 mL of the mixed solution of 0.1% (volume fraction, the same below) formic acid solution and methanol at a volume ratio of 9∶1 was added and vortexed. The solution was passed through a 0.22 μm organic filter membrane, and tulathromycin (calculated based on tulathromycin A) in the filtrate was determined by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Acquity UPLC BEH C18 was used as the stationary phase and the mixed solution composed of 0.1% formic acid solution and methanol at different volume ratios was used as the mobile phase for gradient elution. Electrospray ion (ESI) source was used for mass spectrometry. The targets were analyzed by multiple reaction monitoring (MRM) mode in positive ion (ESI+) scanning mode. As shown by the results, linear relationship between the corresponding peak areas of the quantitative ion pair and mass concentrations of tulathromycin was kept in the range of 0.50-100 μg·L−1, with detection limits (3S/N) in the range of 3.0 μg·kg−1. Test for recovery was made by the standard addition method, giving results in the range of 93.0%-106%, with RSDs (n=5) of the determined values less than 10%. This method was used for the analysis of 38 actual feed samples, and tulathromycin was not detected.

       

    /

    返回文章
    返回