一步式QuEChERS方法结合高效液相色谱-串联质谱法测定牛肉中25种磺胺类药物残留

建立了一种基于一步式QuEChERS自动提取和净化的技术，结合高效液相色谱-串联质谱（high performance liquid chromatography-tandem mass spectrometry, HPLC-MS/MS）同时检测牛肉中25种磺胺类药物残留的检测方法。样品经1%乙酸-乙腈提取，以C₁₈、PSA和无水硫酸镁为净化吸附剂，采用一步式QuEChERS自动化前处理设备提取、净化、离心，经C₁₈色谱柱进行分离，以0.2%甲酸甲醇?0.2%甲酸水（含2 mmol/L乙酸铵）为流动相梯度洗脱，ESI正离子模式扫描，多反应监测（Multi-reaction monitoring, MRM）测定，外标法定量。结果表明，所有化合物在0.1~20 μg/L的浓度范围内线性关系良好，相关系数不低于0.990，检出限（LOD）为0.1~3 μg/kg，定量限（LOQ）为1~10 μg/kg。在1、2和10倍LOQ三个加标浓度水平下，目标化合物的平均回收率范围为70.14%~116.93%，相对标准偏差（RSD）范围为0.95%~13.74%（n=5）。该方法简单快速、准确可靠、可用于检测牛肉中磺胺类药物的残留。

Determination of Sulfonamides in Beef by One Step QuEChERS Method Combined with High Performance Liquid Chromatography-Tandem Mass Spectrometry

The method for simultaneous determination of 25 sulfonamides residues in beef was established by one-step automatic extraction and purification technology of QuEChERS combined with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The sample was extracted with 1% acetonitrile acetate, C₁₈, PSA and anhydrous magnesium sulfate were used as purification adsorbents, and the one-step QuEChERS automatic pretreatment equipment was used for extraction, purification and centrifugation. The analytes were separated by a reversed phase C₁₈ column and eluted with 0.2% formic acid methanol and 0.2% formic acid water (containing 2 mmol/L ammonium acetate). The beef sample was analyzed under the multiple reaction monitoring (MRM) mode with positive electrospray ionization (ESI+) and quantify by external standard. The results showed that good linearities were obtained for the 25 sulfonamides in 0.1~20 μg/L with the linear correlation coefficients more than 0.990. The limits of detection (LOD) and the limits of quantification (LOQ) for sulfonamides were 0.1~3 μg/kg and 1~10 μg/kg, respectively. The recoveries at three levels were in the range of 70.14%~116.93%. The repeatability expressed as relative standard deviations (RSD) was ranged from 0.95% to 13.74%(n=5). The method was simple, rapid, accurate and reliable, and could be used to detect the residues of sulfonamides in beef.