Least squares spectral resolution of liquid chromatography-mass spectrometry data of glycerophospholipids.

Liquid chromatography-mass spectrometry represents a powerful tool for the analysis of intact glycerophospholipids (GPLs), but manual data interpretation may be a bottleneck in these analyses. The present paper proposes a least square regression approach for the automated characterization and deconvolution of the main GPLs species, i.e., phosphatidylcholine and phosphatidylethanolamine analyzed by class-specific scanning methods such as precursor ion scanning and neutral loss scanning, respectively. The algorithm is based on least squares resolution of spectra and chromatograms from theoretically calculated mass spectra, and eliminates the need for isotope correction. Results from the application of the methodology on reference compounds and extracts of cod brain and mouse brain are presented.

Effects of oil pollution and persistent organic pollutants (POPs) on glycerophospholipids in liver and brain of male Atlantic cod (Gadus morhua).

Fish in the North Sea are exposed to relatively high levels of halogenated compounds in addition to the pollutants released by oil production activities. In this study male Atlantic cod (Gadus morhua) were orally exposed to environmental realistic levels (low and high) of weathered crude oil and/or a mixture of POPs for 4weeks. Lipid composition in brain and in liver extracts were analysed in order to assess the effects of the various pollutants on membrane lipid composition and fatty acid profiles. Transcriptional effects in the liver were studied by microarray and quantitative real-time RT-PCR. Chemical analyses confirmed uptake of polychlorinated biphenyls (PCBs) and chlorinated pesticides, polybrominated diphenyl ethers (PBDEs) and perfluorooctanesulfonate (PFOS) in the liver and excretion of metabolites of polyaromatic hydrocarbons (PAHs) in the bile. Treatment with POPs and/or crude oil did not induce significant changes in lipid composition in cod liver. Only a few minor changes were observed in the fatty acid profile of the brain and the lipid classes in the liver. The hypothesis that pollution from oil or POPs at environmental realistic levels alters the lipid composition in marine fish was therefore not confirmed in this study. However, the transcriptional data suggest that the fish were affected by the treatment at the mRNA level. This study suggests that a combination of oil and POPs induce the CYP1a detoxification system and gives an increase in the metabolism and clearing rate of PAHs and POPs, but with no effects on membrane lipids in male Atlantic cod.