离子交换固相萃取-超高效液相色谱-串联质谱法同时测定水产品中泰妙菌素和沃尼妙林残留量

建立了一种强阳离子固相萃取结合超高效液相色谱-串联质谱法同时测定水产品中泰妙菌素和沃尼妙林残留量的分析方法。样品经乙腈提取和Oasis MCX 固相萃取柱净化后，以乙腈-0.05 %甲酸5 mmoL·L^-1乙酸铵水溶液为流动相，经Waters ACQUITY UPLC BEH C₁₈色谱柱梯度洗脱分离，在电喷雾正离子多反应监测模式下，用内标法分析泰妙菌素，用外标法分析沃尼妙林。结果显示，泰妙菌素和沃尼妙林在0.1～10.0 ng·mL^-1内具有良好的线性关系，相关系数r均大于0.999 9，检出限和定量限分别为0.03 和0.1 μg·kg^-1。在0.1，1.0，5.0和10.0 μg·kg^-1 4种添加水平下，加标回收率在87 %～114 %，相对标准偏差在0.87 %～6.50 %。对50条鲫鱼进行实际样品验证，发现在鲫鱼的各个组织中均有泰妙菌素和沃尼妙林残留，其中肾脏残留总量最高，为453.81 μg·kg^-1，肝脏次之，为236.97 μg·kg^-1。结果表明，所建方法能够满足对水产品中泰妙菌素和沃尼妙林残留量的分析要求。

Determination of tiamulin and valnemulin drug residues in aquatic products by ion exchange olid phase extraction-ultra performance liquid chromatography-tandem mass spectrometry

A strong cationic solid phase extraction combined with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the simultaneous determination of tiamulin and valnemulin residues in aquatic products. The sample was extracted with acetonitrile and purified with Oasis MCX SPE cartridge, then was eluted with a gradient of acetonitrile-0.05 % formic acid in 5 mmoL·L^－1 ammonium acetate and eluted with a Waters ACQUITY UPLC BEH C₁₈ column. In the electrospray positive ionization multiple reaction monitoring mode, tiamulin was analyzed by internal standard method and valnemulin was analyzed by external standard method.The results showed that there was a good linear relationship between tiamulin and valnemulin in the range of 0.1～10.0 ng·mL^－1 with the correlation coefficients r is greater than 0.999 9. The limits of detection and quantification limits were 0.03 and 0.1 μg·kg^－1, respectively. The spiked recoveries were between 87 % and 114 % with the relative standard deviations between 0.87 % and 6.50 % at the four addition levels of 0.1, 1.0 ,5.0 and 10.0 μg·kg^－1. Through the actual sample verification of 50 carp, there were residues in the tissues of the carp with the highest content being 453.81 μg·kg^－1 in kidney and the second content being 236.97 μg·kg^－1 in liver. The results show that the established method can meet the analytical requirements of tiamulin and valnemulin residues in aquatic products.