固相萃取-高效液相色谱-串联质谱法同时测定蜂蜡中氯霉素、甲砜氯霉素、氟苯尼考和其代谢产物氟苯尼考胺残留

首次建立了一种同时测定蜂蜡中氯霉素、甲砜氯霉素、氟苯尼考和其代谢物氟苯尼考胺等药物残留的固相萃取-高效液相色谱-串联质谱分析方法。根据蜂蜡脂溶性的特点，试样采用正己烷溶剂预溶解，用水提取2次后经混合型阳离子交换固相萃取柱（MCX）净化，用InertSustain Swift C₁₈柱（100 mm×2.1 mm, 1.9 μm）分离，多反应监测（MRM）模式串联质谱进行测定，以内标法定量。结果表明，在0.1~10 ng/mL范围内4种测定物均具有较好的线性关系，相关系数大于0.99，方法定量限（S/N>10）为0.1 μg/kg。对阴性蜂蜡在0.1、0.3和1.0 μg/kg等3个添加水平下分别进行加标回收试验，实际样品中4种测定物质的平均回收率在65.0%~113.2%之间，相对标准偏差（RSD，n=6）小于20%。应用本方法对15个蜂蜡样品进行检测，结果表明有4批次样品检出氯霉素类药物残留。本方法快速、灵敏、准确，适用于日常大批量蜂蜡样品中氯霉素类药物及其代谢物残留的定性、定量分析。

Determination of Chloramphenicol,Thiamphenicol, Florfenicol and Florfenicol Amine Residues in Beeswax by Solid Phase Extraction-High Performance Liquid Chromatography-Tandem Mass Spectrometry

A method based on solid-phase extraction and high performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry(SPE-HPLC-MS/MS) had been proposed for the determination of chloramphenicol, thiamphenicol, florfenicol and florfenicol amine residues in beeswax. The sample was pre dissolved with n-hexane and then extracted with water, purified the Waters Oasis MCX micro-column and separated on the InertSustain Swift C₁₈ column (100 mm×2.1 mm, 1.9 μm). The determination was carried out with eletrospray ion source and multiple reaction monitoring (MRM) mode and the corresponding quantification was performed by employing the method of internal standards. The calibration curve of mixed standard solution showed a good linearity in the concentration rang from 0.1 to 10 ng/mL with the correlation coefficients (r) more than 0.99. The limits of quantification (S/N>10) for antibiotics were 0.1 μg/kg. The recovery was 65.0% to 113.20% in the spiked concentration 0.1, 0.3 and 1.0 μg/kg, with the relative standard deviations (RSD, n=6) lower than 20%.The method was applied to detect 15 beeswax samples, and the results showed that chloramphenicol residues were detected in 4 batches of samples. The method is rapid, sensitive and accurate, and could be applied for the qualitative and quantitative analysis of chloramphenicol, thiamphenicol, florfenicol and florfenicol amine residues antibiotics in beeswax.