Haglund Peter, Korytár Peter, Danielsson Conny, Diaz Jordí, Wiberg Karin, Leonards Pim, Brinkman Udo A T, de Boer Jacob
Department of Chemistry, Umeå University, 901 87, Umeå, Sweden.
Anal Bioanal Chem. 2008 Apr;390(7):1815-27. doi: 10.1007/s00216-008-1896-0. Epub 2008 Feb 7.
There is a need for cost-efficient alternatives to gas chromatography (GC)-high-resolution mass spectrometry (HRMS) for the analysis of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (PCBs) in food and feed. Comprehensive two-dimensional GC-micro electron capture detection (GC x GC-microECD) was tested and all relevant (according to the World Health Organisation, WHO) PCDD/Fs and PCBs could be separated when using a DB-XLB/LC-50 column combination. Validation tests by two laboratories showed that detectability, repeatability, reproducibility and accuracy of GC x GC-microECD are all statistically consistent with GC-HRMS results. A limit of detection of 0.5 pg WHO PCDD/F tetrachlorodibenzo-p-dioxin equivalency concentration per gram of fish oil was established. The reproducibility was less than 10%, which is below the recommended EU value for reference methods (less than 15%). Injections of vegetable oil extracts spiked with PCBs, polychlorinated naphthalenes and diphenyl ethers at concentrations of 200 ng/g showed no significant impact on the dioxin results, confirming in that way the robustness of the method. The use of GC x GC-microECD as a routine method for food and feed analysis is therefore recommended. However, the data evaluation of low dioxin concentrations is still laborious owing to the need for manual integration. This makes the overall analysis costs higher than those of GC-HRMS. Further developments of software are needed (and expected) to reduce the data evaluation time. Combination of the current method with pressurised liquid extraction with in-cell cleanup will result in further reduction of analysis costs.
在食品和饲料中多氯二苯并 - 对 - 二噁英和二苯并呋喃（PCDD/Fs）以及二噁英类多氯联苯（PCBs）的分析方面，需要有比气相色谱（GC）-高分辨率质谱（HRMS）成本效益更高的替代方法。对全二维气相色谱-微电子捕获检测（GC×GC-微ECD）进行了测试，当使用DB-XLB/LC-50柱组合时，可以分离所有相关的（根据世界卫生组织，WHO）PCDD/Fs和PCBs。两个实验室进行的验证测试表明，GC×GC-微ECD的可检测性、重复性、再现性和准确性在统计学上均与GC-HRMS结果一致。确定了每克鱼油中0.5皮克WHO PCDD/F四氯二苯并 - 对 - 二噁英当量浓度的检测限。再现性小于10%，低于欧盟参考方法推荐值（小于15%）。对添加浓度为200纳克/克的多氯联苯、多氯萘和二苯醚的植物油提取物进行进样，对二噁英结果没有显著影响，从而证实了该方法的稳健性。因此，建议将GC×GC-微ECD用作食品和饲料分析的常规方法。然而，由于需要手动积分，低二噁英浓度的数据评估仍然很费力。这使得总体分析成本高于GC-HRMS。需要（并且有望）进一步开发软件以减少数据评估时间。将当前方法与带柱内净化的加压液体萃取相结合将进一步降低分析成本。
