气相色谱-串联质谱法测定竹木砧板表层中五氯酚的含量

Determination of Pentachlorophenol on the Surface of Wooden Chopping Board by Gas Chromatography-Tandem Mass Spectrometry

建立了气相色谱-串联质谱法测定竹木砧板中五氯酚含量的方法。通过表层取样法与九点式布点法联合制备样品后,在2.00 g样品中加入10.0 mg·L^(-1)的2,4,6-三溴酚内标溶液50μL,以体积比1∶9的乙酸乙酯-正己烷混合液10 mL为提取剂,经SLC固相萃取柱净化后,洗脱液氮吹至1.0 mL,用体积比1∶1的乙酸酐-吡啶混合液进行衍生。样品衍生后,在Agilent J&W DB-5MS石英毛细管色谱柱上采用柱升温程序进行分离。质谱分析中采用多反应监测模式检测,内标法定量。结果表明:五氯酚的质量浓度在25~800μg·L^(-1)内与五氯酚衍生物和2,4,6-三溴酚衍生物的峰面积比值呈线性关系,检出限(3S/N)为0.003 mg·kg^(-1)。按标准加入法进行回收试验,测得回收率为86.0%~96.0%,测定值的相对标准偏差(n=5)均小于5.0%。按此方法对80份竹木砧板样品开展食品安全风险专项监测,发现非定型包装竹木砧板中五氯酚高残留量(高达384.350 mg·kg^(-1))的风险隐患,为相关部门提供了风险预警。

A method was established for the determination of pentachlorophenol in wooden chopping board by gas chromatography-tandem mass spectrometry(GC-MS/MS).The samples were prepared by the surface sampling method and the nine-point layout method.2,4,6-tribromophenol internal standard solution of 10.0 mg·L^(-1)(50μL)was added into the sample of 2.00 g,and a mixture of ethyl acetate and n-hexane at volume ratio of 1∶9(10 mL)was used as the extractant.After purification by SLC solid phase extraction column,the eluent was blown to 1.0 mL with nitrogen,and a mixture of acetic anhydride and pyridine at volume ratio of 1∶1 was used for derivatization.After derivatization,the sample was separated on Agilent J&W DB-5 MS quartz capillary column by column temperature program.The mode of multireaction monitoring(MRM)was adopted in MS/MS,and internal standard method was used for quantitative analysis.The results showed that linear relationship between peak area ratio of pentachlorophenol derivative and 2,4,6-tribromophenol derivative and mass concentration of pentachlorophenol was found in the range of 25-800μg·L^(-1),with detection limit(3 S/N)of 0.003 mg·kg^(-1).Test for recovery was made by standard addition method,giving results in the range of 86.0%-96.0%,and RSDs(n=5)of the determined values less than 5.0%.This method was used to carry out special food safety risk monitoring on 80 samples of wooden chopping board,and the hidden risk of high residues of pentachlorophenol(up to 384.350 mg·kg^(-1))in non-shaped packaging wooden chopping boards was discovered,which provided risk early warning for relevant departments.