亲水作用色谱-串联质谱法测定蜂蜜中链霉素和双氢链霉素残留

建立了亲水作用色谱-串联质谱(HILIC-MS/MS)测定蜂蜜中链霉素和双氢链霉素的分析方法.样品中链霉素和双氢链霉素经20 g/L三氯乙酸水溶液(含50 mmol/L磷酸盐,pH 6.8)提取,HLB固相萃取柱净化,采用HILIC-MS/MS对目标物进行定性和定量分析.采用SIELC Obelisc R色谱柱,以0.5%(体积分数)甲酸水溶液和乙腈为流动相进行梯度洗脱分离,在正离子模式下检测,外标法定量.该方法在2.5~100μg/L范围内线性关系良好(r>0.99),检出限(LOD)为2.0μg/kg,定量限(LOQ)为5.0μg/kg.在空白蜂蜜样品中进行5.0、20.0、100.0μg/kg3个水平的加标回收试验,方法的平均回收率为86.9% ~113.2%,精密度在10% 以下.该方法简单、快速、灵敏,重复性好,可用于蜂蜜中链霉素和双氢链霉素的定量测定.

Determination of streptomycin and dihydrostreptomycin residues in honey by hydrophilic interaction liquid chromatography-tandem mass spectrometry

An analytical method was developed for the determination of streptomycin and dihydrostreptomycin in honey using hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS). The streptomycin and dihydrostreptomycin residues in the test samples were extracted with 20 g/L trichloroacetic acid aqueous solution (including 50 mmol/L phosphate, pH 6.8) and cleaned on an Oasis HLB solid phase extraction column. The products were separated on a SIELC Obelisc R column with gradient elution using 0.5% (v/v) formic acid aqueous solution and acetonitrile as mobile phases. Streptomycin and dihydrostreptomycin were detected by liquid chromatography-tandem mass spectrometry in the positive ion mode using the external standard method. Under the optimal conditions, streptomycin and dihydrostreptomycin showed good linearity (r>0.99) in the range of 2.5-100 μg/L. The LOD and LOQ of the method was 2.0 μg/kg and 5.0 μg/kg, respectively. The spiked recoveries of the analytes from blank honey samples at the three levels of 5.0, 20.0 and 100.0 μg/kg were in the range of 86.9%-113.2% with the relative standard deviations less than 10%. With the advantages of convenience, rapidity, sensitivity and good repeatability, the method is suitable for the detection of streptomycin and dihydrostreptomycin in honey.