快速溶剂萃取-凝胶渗透色谱净化-LC/MS/MS结合测定蜂花粉中硝基咪唑类药物

Determination of nitroimidazoles residues in bee pollen using LC-MS/MS coupled with accelerated solvent extraction and gel permeation chromatographic purification

目的:建立了快速溶剂萃取-凝胶渗透色谱净化-LC/MS/MS测定蜂花粉中硝基咪唑类化合物的分析方法。方法:样品以乙酸乙酯为萃取溶剂经快速溶剂萃取仪萃取,凝胶渗透色谱(GPC)净化,采用Zorbax Eclipse Plus C18色谱柱(2.1 mm×100 mm,3.5μm)分离,以0.15%甲酸溶液(A)-甲醇(B)为流动相,梯度洗脱(0~2 min,90%A;2~5 min,90%A→40%A;5~7 min,40%A→10%A;7~7.5 min,10%A→90%A;7.5~12.0 min,90%A),流速为0.3 m L·min^(-1)。质谱采用多反应监测正离子扫描模式,基质匹配标准曲线同位素内标法定量。结果:硝基咪唑类化合物在一定范围内(1.0~15.0 ng·m L^(-1))线性良好,相关系数在0.996 1~0.998 2内;硝基咪唑类化合物检出限为1.5μg·kg^(-1),定量限为5.0μg·kg^(-1);加标5.0μg·kg^(-1)时回收率为98.0%~114.2%,10.0μg·kg^(-1)时回收率为93.5%~104.0%,20.0μg·kg^(-1)时回收率为93.6%~101.2%,RSD分别为2.3%~5.2%、1.0%~1.1%和0.3%~1.7%。结论:该方法自动化程度高、灵敏度高,定性和定量结果准确。

Objective：To develop a method based on accelerated solvent extraction and gel permeation chromatography for analysis of nitroimidazoles residues in bee pollen.Methods：Sample was extracted with ethyl acetate using accelerated solvent extraction and purified by gel permeation chromatography.The Agilent Zorbax Eclipse Plus C18 column（2.1 mm×100 mm,3.5 μm）was adopted for the study.The mobile phase consisting of 0.15% formic acid solution（A）-methonal（B）with gradient elution（0-2 min,90%A;2-5 min,90%A → 40%A;5-7 min,40%A → 10%A;7-7.5 min,10%A → 90%A;7.5-（-1）2.0 min,90%A）at a flow rateof 0.3 mL ·min-（-1）.Mass spectrometer was operated in the positive ion mode using select reaction monitoring.Matrix-matched calibration curve and isotope internal standard was used for quantitative analysis.Results：The linearity of the calibration curve was obtained from 1.0 to 15.0 ng·m L-（-1） with correlation coefficient of 0.996 1-0.998 2.The limit of detection in the method was 1.5 μg·kg-（-1）,and the limit of quantitation was 5.0 μg·kg-（-1）.The average recoveries of nitroimidazoles at three levels of 5.0,10.0 and 20.0 μg·kg-（-1） were in the range of 98.0%-（-1）14.2%,93.5%-（-1）04.0%si oannd 93.6%-（-1）01.2% respectively;the RSDs were 2.3%-5.2%,1.0%-（-1）.1% and 0.3%-（-1）.7%.Conclu：The established method is proved to be of high degree of automation,high sensitivity,and accuracy at both qualitative and quantitative analysis.