Bordet François, Inthavong Dary, Fremy Jean-Marc
Agence Française de Sécurité Sanitaire des Aliments, Unité Contaminants de l'Environnement, Maisons-Alfort, Paris, France.
J AOAC Int. 2002 Nov-Dec;85(6):1398-409.
An interlaboratory study was conducted to validate a gas chromatographic (GC) method for determination of 21 organochlorine pesticides, 6 pyrethroid pesticides, and 7 polychlorobiphenyl (PCB) congeners in milk, beef fat, fish, and eggs. The method was performed at low contamination levels, which represent relevant contents in food, and is an extension of the European standard (method NF-EN-1528, Parts 1-4). It enlarges the applicable scope of the reference EN method to pyrethroid pesticides and proposes the use of solid-phase extraction (SPE) as a cleanup procedure. Cryogenic extraction was made, and SPE cleanup was performed with 2 successive SPE cartridges: C18 and Florisil. After injection of the purified extract onto a GC column, residues were measured by electron capture detection. Food samples (liquid milk, beef fat, mixed fish, and mixed eggs) were prepared, tested for homogeneity, and sent to 17 laboratories in France. Test portions were spiked with 27 pesticides and 7 PCBs at levels from 26 to 45, 4 to 27, 31 to 67, and 19 to 127 ng/g into milk, eggs, fish, and fat, respectively. Based on results for spiked samples, the relative standard deviation for repeatability ranged from 1.5 to 6.8% in milk, 3 to 39% in eggs, 4.5 to 12.2% in fish, and 7 to 13% in fat. The relative standard deviation for reproducibility ranged from 33 to 50% in milk, 29 to 59% in eggs, 31 to 57% in fish, and 30 to 62% in fat. This method showed acceptable intra- and interlaboratory precision data, as corroborated by HORRAT values at low levels of pesticide and PCB contamination. The statistical evaluation of the results was performed according to the International Organization for Standardization (ISO; ISO 3534 standard) and 5725-2 Guideline.
开展了一项实验室间研究，以验证一种气相色谱（GC）方法，用于测定牛奶、牛肉脂肪、鱼类和蛋类中的21种有机氯农药、6种拟除虫菊酯类农药和7种多氯联苯（PCB）同系物。该方法在低污染水平下进行，这代表了食品中的相关含量，并且是欧洲标准（方法NF - EN - 1528，第1 - 4部分）的扩展。它将参考EN方法的适用范围扩大到拟除虫菊酯类农药，并建议使用固相萃取（SPE）作为净化程序。进行了低温萃取，并用2个连续的SPE柱（C18和弗罗里硅土）进行SPE净化。将纯化后的提取物注入GC柱后，通过电子捕获检测测定残留量。制备了食品样品（液态奶、牛肉脂肪、混合鱼类和混合蛋类），检测其均匀性，并将其送至法国的17个实验室。分别向牛奶、蛋类、鱼类和脂肪的测试部分中添加27种农药和7种PCBs，添加水平分别为26至45、4至27、31至67和19至127 ng/g。根据加标样品的结果，牛奶中重复性的相对标准偏差范围为1.5%至6.8%，蛋类中为3%至39%，鱼类中为4.5%至12.2%，脂肪中为7%至13%。再现性的相对标准偏差范围为，牛奶中为33%至50%，蛋类中为29%至59%，鱼类中为31%至57%，脂肪中为30%至62%。该方法显示出可接受的实验室内和实验室间精密度数据，低水平农药和PCB污染时的HorRat值证实了这一点。结果的统计评估是根据国际标准化组织（ISO；ISO 3534标准）和5725 - 2指南进行的。
