Development of a Sustainable Enrichment Strategy for Quantification of Mercury Ions in Complex Samples at the Sub-Parts per Billion Level

To limit environmental exposure of mercury species, government bodies restrict emissions of various environmental mercury sources to sub-parts per billion (ppb) levels. Current methods for detection of mercury are time-consuming and expensive and suffer from many drawbacks. Optical methods are in principle less intensive but have not yet been implemented for real-world applications because of a lack of sufficient sensitivity and robustness. We previously reported a fluorometric method for quantifying mercury ions based on the oxymercuration of a vinyl ether with a detection limit of 1 ppb, not meeting the requirement by government bodies. To fill the gap between our previous method and the governments’ restrictions, we have developed a method to enrich complex samples with mercury ions through the use of a recyclable thiol-based resin and the novel chemistry of mercury release. The combination of our previous fluorometric method and the new enrichment chemistry allowed the detection of 0.1 ppb mercury in a complex synthetic sample