UPLC-Q-TOF/MS法测定桂皮中香豆素含量

为降低基质干扰，样品经粉碎过筛后，通过响应面试验优化桂皮前处理条件，采用稳定同位素稀释结合超高效液相色谱-四极杆飞行时间质谱（UPLC-Q-TOF/MS）法测定香豆素含量，并进行方法学考察。结果表明，桂皮中香豆素的最优超声提取条件为甲醇作为提取溶剂，甲醇用量25 mL，提取时间25 min，提取温度50 ℃，重复提取2次。在此条件下，采用稳定同位素稀释结合UPLC-Q- TOF/MS测定香豆素，内标法定量，使用香豆素-d4为内标物进行基质效应的校正，香豆素质量浓度在0.01～2.0 mg/L范围内，线性关系良好，相关系数R2为0.999 3，平均回收率为89.9%～99.9%，精密度试验结果的相对标准偏差（RSD）为1.58%～3.22%，方法检出限（LOD）为0.3 mg/kg，定量限（LOQ）为1.0 mg/kg，说明该方法操作简便、灵敏度高，回收率及精密度较好，可应用于桂皮中香豆素含量的测定。

Determination of coumarin content in cinnamon by UPLC-Q-TOF/MS

In order to reduce the matrix interference, the pretreatment conditions of coumarin were optimized by response surface tests after the samples were crushed and sieved, the coumarin content was determined by stable isotope dilution combined with ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS), and methodological investigation was conducted. The results showed that the optimal ultrasonic extraction conditions of coumarin in cinnamon were as follows: methanol as extraction solvent, methanol dosage 25 ml, extraction time 25 min, temperature 50 ℃, and repeated extraction twice. Under these conditions, the coumarin was determined by stable isotope dilution combined with UPLC-Q-TOF/MS, and quantified by internal standard method. Coumarin-d4 was used as the internal standard for matrix effect correction. Coumarin exhibited good linearity with the mass concentration range of 0.01-2.0 mg/L, the correlation coefficient R2 was 0.999 3, the average recovery rate was 89.9%-99.9%, the relative standard deviation (RSD) of precision test results was 1.58%-3.22%, the limit of detection (LOD) of the method was 0.3 mg/kg, and the limit of quantification (LOQ) was 1.0 mg/kg, indicating that the method was simple and sensitive with high recovery rate and good precision, and could be used for the determination of coumarin content in cinnamon.