A rapid analytical method to quantify complex organohalogen contaminant mixtures in large samples of high lipid mammalian tissues. (June 2017)

• Record Type: Journal Article
• Authors: Desforges, Jean-Pierre; Eulaers, Igor; Periard, Luke; Sonne, Christian; Dietz, Rune; Letcher, Robert J.
• Is Part Of: Chemosphere. Volume 176(2017)
• Page Start: 243
• Page End: 248
• Publication Date: 2017-06
• Subjects: Mixture toxicology -- Realistic exposure -- Freeze-lipid filtration -- Marine mammal -- Polychlorinated biphenyls -- Flame retardants; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2017.02.098
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: 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 13 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. Graphical abstract: Highlights: A rapid and easy extraction method for organohalogen contaminants (OHCs) in large blubber samples is described. Freeze-filtration removes up to 97% of lipids in blubber samples ranging from 0.1 to 55 g. Recovery, accuracy and precision for OHCs similar to conventional small sample extraction methods. Useful method to generate contaminant cocktails or as simple replacement for traditional protocols.