Passive Sampling and High Resolution Mass Spectrometry for Chemical Profiling of French Coastal Areas with a Focus on Marine Biotoxins.

Passive samplers (solid phase adsorption toxin tracking: SPATT) are able to accumulate biotoxins produced by microalgae directly from seawater, thus providing useful information for monitoring of the marine environment. SPATTs containing 0.3, 3, and 10 g of resin were deployed at four different coastal areas in France and analyzed using liquid chromatography coupled to high resolution mass spectrometry. Quantitative targeted screening provided insights into toxin profiles and showed that toxin concentrations and profiles in SPATTs were dependent on the amount of resin used. Between the three amounts of resin tested, SPATTs containing 3 g of resin appeared to be the best compromise, which is consistent with the use of 3 g of resin in SPATTs by previous studies. MassHunter and Mass Profiler Professional softwares were used for data reprocessing and statistical analyses. A differential profiling approach was developed to investigate and compare the overall chemical diversity of dissolved substances in different coastal water bodies. Principal component analysis (PCA) allowed for spatial differentiation between areas. Similarly, SPATTs retrieved from the same location at early, medium, and late deployment periods were also differentiated by PCA, reflecting seasonal variations in chemical profiles and in the microalgal community. This study used an untargeted metabolomic approach for spatial and temporal differentiation of marine environmental chemical profiles using SPATTs, and we propose this approach as a step forward in the discovery of chemical markers of short- or long-term changes in the microbial community structure.