同位素稀释的气相色谱/高分辨质谱联用测定食品中二噁英和共平面多氯联苯

采用HRGC/HRMS和同位素稀释定量技术对样品中17种4~8个氯原子取代的二噁英和呋喃(PCDDs/Fs)与12种共平面多氯联苯(PCBs)定量分析。样品经索式抽提、FMSPowerPrep系统净化、浓缩,利用高分辨气相色谱/高分辨质谱联用仪的多离子检测方式,同位素稀释技术对样品中的目标化合物进行定性和定量。该方法的检出限为pg/g水平。13C同位素内标回收率范围为47%~100%。对3个CRM鱼样中17个PCDDs/Fs和4个PCBs的检测值均在标准定值允许误差范围内。对5个不同的实际样品鱼进行测定表明,样品的回收率在48%~100%之间,回收率的相对标准偏差小于20%;对同一样品进行定量检测的精密度测试结果表明,17种PCDDs/Fs浓度的RSD低于16%,12种PCBs浓度的RSD低于11%。本方法定量分析重现性良好。

Determination of Polychlorinated Dibenzo-p-dioxins and Furans and Co-polar Polychlorinated Biphenyls in Fat Food by Isotope Dilution High Resolution Gas Chromatography/High Resolution Mass Spectrometry

A sensitive and accurate method has been developed for the simultaneously determination of 17 ~2,3,7,8 -substituted congeners of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) and 12 co-polar polychlorinated biphenyls (Co-PCBs) in fat food as fish sample using isotope dilution high resolution gas chromatography/high resolution mass spectro-metry (HRGC/HRMS). PCDD/Fs and Co-PCBs were extracted from the sample by soxhlet extraction, concentrated and purified as well as isolated by FMS Power Prep. Confirmative and quantitative analysis of PCDD/Fs at pg/g level was performed by HRGC/HRMS using multiple ion detection mode (MID) and isotope dilution high resolution gas chromatography/high resolution mass ~spectro- ~metry . The recoveries of 17 PCDDs/Fs and 12 Co-PCBs isotopically labelled standards were found to be in the range of 47%~100%. The quantitative value of 17 PCDDs/Fs and 4 PCBs concentration in fish certified ~reference material (CRM) was droped in the range of certified value. The recoveries of internal standards in 5 different real fish samples were 48%~100%, RSD<20%. And the precision of quantitation PCDDs/Fs and Co-PCBs in sleeve-fish was also determined, RSD were less than 16% and 11%, respectively. This method is a good analysis system in confirmation and quatitation for simultaneous determination of PCDDs/Fs and PCBs.