Desforges Jean-Pierre, Eulaers Igor, Periard Luke, Sonne Christian, Dietz Rune, Letcher Robert J
Department of Bioscience, Arctic Research Centre, Aarhus University, Frederiksborgvej 399, PO Box 358, DK-4000, Roskilde, Denmark.
Ecotoxicology and Wildlife Health Division, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON, K1A 0H3, Canada.
Chemosphere. 2017 Jun;176:243-248. doi: 10.1016/j.chemosphere.2017.02.098. Epub 2017 Feb 24.
In vitro investigations of the health impact of individual chemical compounds have traditionally been used in risk assessments. However, humans and wildlife are exposed to a plethora of potentially harmful chemicals, including organohalogen contaminants (OHCs). An alternative exposure approach to individual or simple mixtures of synthetic OHCs is to isolate the complex mixture present in free-ranging wildlife, often non-destructively sampled from lipid rich adipose. High concentration stock volumes required for in vitro investigations do, however, pose a great analytical challenge to extract sufficient amounts of complex OHC cocktails. Here we describe a novel method to easily, rapidly and efficiently extract an environmentally accumulated and therefore relevant contaminant cocktail from large (10-50 g) marine mammal blubber samples. We demonstrate that lipid freeze-filtration with acetonitrile removes up to 97% of blubber lipids, with minimal effect on the efficiency of OHC recovery. Sample extracts after freeze-filtration were further processed to remove residual trace lipids via high-pressure gel permeation chromatography and solid phase extraction. Average recoveries of OHCs from triplicate analysis of killer whale (Orcinus orca), polar bear (Ursus maritimus) and pilot whale (Globicephala spp.) blubber standard reference material (NIST SRM-1945) ranged from 68 to 80%, 54-92% and 58-145%, respectively, for C-enriched internal standards of six polychlorinated biphenyl congeners, 16 organochlorine pesticides and four brominated flame retardants. This approach to rapidly generate OHC mixtures shows great potential for experimental exposures using complex contaminant mixtures, research or monitoring driven contaminant quantification in biological samples, as well as the untargeted identification of emerging contaminants.
对单一化合物健康影响的体外研究传统上一直用于风险评估。然而，人类和野生动物会接触到大量潜在有害化学物质，包括有机卤素污染物（OHCs）。一种替代单一或简单合成OHCs混合物的暴露方法是分离自由放养野生动物体内存在的复杂混合物，这些混合物通常是从富含脂质的脂肪中无损采样得到的。然而，体外研究所需的高浓度储备量对提取足够量的复杂OHC混合物构成了巨大的分析挑战。在这里，我们描述了一种新颖的方法，可轻松、快速且高效地从大型（10 - 50克）海洋哺乳动物脂肪样本中提取环境累积且因此相关的污染物混合物。我们证明，用乙腈进行脂质冷冻过滤可去除高达97%的脂肪脂质，对OHC回收率的影响最小。冷冻过滤后的样品提取物通过高压凝胶渗透色谱和固相萃取进一步处理以去除残留的微量脂质。对虎鲸（Orcinus orca）、北极熊（Ursus maritimus）和领航鲸（Globicephala spp.）脂肪标准参考物质（NIST SRM - 1945）进行一式三份分析时，六种多氯联苯同系物、16种有机氯农药和四种溴化阻燃剂的碳富集内标物的OHC平均回收率分别为68%至80%、54%至92%和58%至145%。这种快速生成OHC混合物的方法在使用复杂污染物混合物进行实验暴露、生物样品中由研究或监测驱动的污染物定量以及新兴污染物的非靶向识别方面显示出巨大潜力。
