Optimization and uncertainty assessment of a gas chromatography coupled to Orbitrap mass spectrometry method to determine organic contaminants in blood: A case study of an endangered seabird

• Published in: Journal of Chromatography A
• Main Authors: Oró-Nolla, Bernat, Campioni, Letizia, Lacorte Bruguera, Silvia
• Other Authors: Ministerio de Ciencia y Tecnología (España), orcid:
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2024
• Subjects: High resolution mass spectrometry; Avian blood; Organochlorine pesticides; Polybrominated diphenyl ethers; Polychlorinated biphenyls; Polycyclic aromatic hydrocarbons; Pterodroma cahow; Ensure healthy lives and promote well-being for all at all ages; Gjerdrum; Jeremy; Northwest Atlantic
• Online Access: http://hdl.handle.net/10261/354331; https://doi.org/10.1016/j.chroma.2024.464870; https://doi.org/10.13039/501100006280; https://api.elsevier.com/content/abstract/scopus_id/85189941320

Birds are excellent bioindicators of environmental pollution, and blood provides information on contaminant exposure, although its analysis is challenging because of the low volumes that can be sampled. The objective of the present study was to optimize and validate a miniaturized and functional extraction and analytical method based on gas chromatography coupled to Orbitrap mass spectrometry (GCOrbitrap-MS) for the trace analysis of contaminants in avian blood. Studied compounds included 25 organochlorine pesticides (OCPs), 6 polychlorinated biphenyls (PCBs), 8 polybrominated diphenyl ethers (PBDEs) and 15 polycyclic aromatic hydrocarbons (PAHs). Four extraction and clean-up conditions were optimized and compared in terms of efficiency, accuracy, and uncertainty assessment. Extraction with hexane:dichloromethane and miniaturized Florisil pipette clean-up was the most adequate considering precision and accuracy, time, and costs, and was thereafter used to analyse 20 blood samples of a pelagic seabird, namely the Bermuda petrel (Pterodroma cahow). This species, endemic to the Northwest Atlantic, is among the most endangered seabirds of the region that in the '60 faced a decrease in the breeding success likely linked to a consistent exposure to dichloro-diphenyl-trichloroethane (DDT). Indeed, p,p'-DDE, the main DDT metabolite, was detected in all samples and ranged bewteen 1.13 and 6.87 ng/g wet weight. Other ubiquitous compounds were PCBs (ranging from 0.13 to 6.76 ng/g ww), hexachlorobenzene, and mirex, while PAHs were sporadically detected at low concentrations, and PBDEs were not present. Overall, the extraction method herein proposed allowed analysing very small blood volumes (∼ 100 µL), thus respecting ethical principles prioritising the application of less-invasive sampling protocols, fundamental when studying threatened avian species. We are particularly grateful to Jeremy Madeiros and Carina Gjerdrum for their great help to collect the blood samples and to J-P Rouja who helped with the logistic of ...