气相色谱-质谱联用法测定饲料中的多氯联苯Aroclor 1242系列

Determination of Aroclor 1242 PCBs in feed by GC-MS

建立饲料中多氯联苯Aroclor 1242系列的气相色谱-质谱联用分析方法。Aroclor 1242标准溶液经GC-MS全扫描定性和选择离子定量后,按含氯数对各氯代联苯峰进行归类,制作标准曲线,线性关系良好,相关系数r>0.99。样品经索氏提取、浓硫酸磺化、硅胶柱净化并浓缩定容至2 mL,经GC-MS测定,外标法定量,Aroclor 1242含量均低于方法检测限。加标试验的回收率在80%-115%之间。该方法简易可靠,在多氯联苯Aroclor系列的检测和评价方式上作出创新改进,具有实用价值。

To establish an analytical method of GC-MS for determination of Aroclor 1242 PCBs in feed, the Aroclor 1242 standard mixture was identified by GC-MS full scan and quantitated by selected ion monitor （SIM）. PCB peaks were classified by their chlorine numbers and standard curves were plotted respectively. All the regression curves revealed good linearity, with the correlation coefficient r higher than 0.99. The feed samples were extracted with Soxhlet method, then sulfonated by concentrated H2SO4. The extract was purified by passing through silica gel column. The elute was concentrated and made up to 2 mL, which was determined by GC-MS. Quantitation with external standard method showed that PCB content in all the feed samples were lower than the detection limit. Values of recovery ranging from 80% to 115% were obtained by addition of Aroclor 1242 solution to a feed sample as matrix which was then analyzed by the proposed method. This method is simple and reliable to be implemented. It is also of practical value with innovative improvement in the detection and evaluation of Aroclor PCB series.