分散固相萃取-超高效液相色谱-串联质谱法测定奶粉中7种非选择性环氧化酶抑制药物

建立并优化了使用分散固相萃取-超高效液相色谱-串联质谱(dSPE-UPLC-MS/MS)检测奶粉中7种非选择性环氧化酶(COX)抑制药物残留的方法。样品用0.01 mol/L pH 2.5抗坏血酸溶液-乙腈-乙酸乙酯(2∶5∶5, v/v/v)溶液提取后,加入无水硫酸钠、十八烷基键合硅胶吸附剂(C₁₈-N)及NH_2-丙基乙二胺吸附剂(NH_2-PSA)组成的盐包进行净化。以Waters CORTECS UPLC C₁₈(100 mm×2.1 mm, 1.6μm)色谱柱分离,流动相为0.1%(体积分数)甲酸水溶液和0.1%(体积分数)甲酸乙腈,配合多反应监测(MRM)模式定性定量分析水杨酸、布洛芬、双氯芬酸钠、吲哚美辛、吡罗昔康、萘普生和保泰松7种成分。结果表明:7种化合物线性相关性良好,相关系数(r^2)≥0.995 7。高、中、低3个水平下,加标回收率为76.4%～89.8%。定量限为2～5μg/kg。该方法前处理简单,回收率高,重现性好,可作为奶粉中7种非选择性COX抑制药物残留的有效检测方法。

Determination of seven non-selective cyclooxygenase inhibitors in milk powder by ultra-performance liquid chromatography-tandem mass spectrometry with dispersive solid phase extraction

An ultra-performance liquid chromatography-tandem mass spectrometry with dispersive solid phase extraction (dSPE-UPLC-MS/MS) method was developed to determine seven non-selective cyclooxygenase inhibitors in milk powder. The samples were extracted with 0.01 mol/L pH 2.5 ascorbic acid-acetonitrile-ethyl acetate solution (2:5:5, v/v/v), and then purified with a mixture of anhydrous sodium sulfate, octadecyl carbon silica gel (C₁₈-N) sorbent and ethylenediamine-N-propyl carbon silica gel (NH₂-PSA) sorbent. The analysis was performed using a UPLC-MS/MS system with Waters CORTECS UPLC C₁₈ (100 mm×2.1 mm, 1.6 μm) column. The mobile phase consisted of 0.1% (v/v) formic acid aqueous solution and acetonitrile containing 0.1% (v/v) formic acid by gradient elution, and the multiple reaction monitoring (MRM) mode was used. Five linear calibration curves were obtained with correlation coefficients (r²) ≥ 0.9965. The recoveries were determined at three spiked levels and ranged from 76.4% to 89.8%. The limits of quantification (LOQs) were from 2 to 5 μg/kg. This method is suitable for the determination of seven non-selective cyclooxygenase inhibitors in milk powder.