气相色谱-质谱法测定小麦中二噁英类多氯联苯

Determination of dioxin-like polychlorinated biphenyls in wheat by gas chromatography-mass spectrometry

中文关键词:  二噁英类多氯联苯  小麦  气相色谱-质谱法

英文关键词:dioxin-like polychlorinated biphenyls  wheat  gas chromatograph-mass spectrometry

中文摘要:

      目的 建立气相色谱-质谱法(Gas chromatograph-mass spectrometry, GC-MS)同时快速测定小麦中12种二噁英类多氯联苯(dioxin-like polychlorinated biphenyls, DL-PCBs)的分析方法。方法 样品采用改进的QuEChERS方法, 经丙酮-正己烷(1:2, V:V)溶液超声提取, 羧基化多壁碳纳米管和N-丙基乙二胺混合净化剂净化, 用Agilent HP-5MS色谱柱分离, GC-MS选择离子监测模式进行测定, 外标法定量。结果 12种DL-PCBs在5~500 μg/L范围内具有良好的线性关系, 相关系数r均大于0.999。方法的检出限为0.5~0.8 μg/kg, 定量限均为5 μg/kg, 在5、10、100 μg/kg添加水平的平均回收率为88.6%~115.0%, 相对标准偏差小于6.5%(n=5)。结论 该方法样品前处理简单快速, 溶剂消耗少, 对检测条件要求低, 适用于同时测定小麦中12种DL-PCBs。

英文摘要:

      Objective To establish a simple and rapid method for the simultaneous determination of 12 dioxin-like polychlorinated biphenyls (DL-PCBs) in wheat by gas chromatography-mass spectrometry (GC–MS). Methods The wheat samples were ultrasonically extracted with acetone-hexane (1:2, V:V). Subsequently, the extract was cleaned-up by using carboxylated multi-walled carbon nanotubes and primary secondary amine as adsorbents according to the method of QuEChERS. Then, the DL-PCBs in the extract were separated on an Agilent HP-5MS capillary column, detected by GC-MS using selected ion monitoring mode, and quantified by external standard method. Results Good linear relationships for all the analytes were observed in the concentration range of 5–500 μg/L with correlation coefficients more than 0.995. The limits of detection and the limits of quantification were 0.5–0.8 μg/kg and 5 μg/kg, respectively, the recoveries were ranged from 88.6% to 115.0% for the analytes with 3 spiked levels of 5, 10 and 100 μg/kg, and the relative standard deviations were less than 6.5% (n=5). Conclusion The proposed method is simple, accurate, solvent saving and without special instrument sensitive, which is suitable for detecting DL-PCBs in wheat.