In situ chemical exploration of underwater ecosystems with microsampling/enrichment device

The study of organic compounds present in water surrounding marine organisms can be useful for a better understanding of ecosystem dynamics, since these compounds may be important in signaling. However, the detection of organic compounds underwater is challenging, as they are present at very low levels. We introduce in situ solid-phase microextraction (SPME) as a non-invasive and non-polluting technique for simultaneous underwater sampling and extraction of small molecules. Analyses were conducted with a LC-MS method using a benchtop orbitrap instrument in both positive and negative modes. We provided preliminary results on the ability of SPME fibers to extract simultaneously around 280 compounds with a wide range of polarities (logP from -2.6 to 15.3), including short-lived intermediates, directly from underwater. We envision that this approach can offer new opportunities to explore underwater ecosystems dynamics.