Xanthate is a collector chemical widely used in the beneficiation of sulfide metals such as copper, lead, etc.  We developed an electrode based on fluorous sensing membranes to measure xanthate usage in a flotation cell.  Flotation is a solid-solid separations process that selectively separates the desired substance from the undesired waste material.  In the case of copper, the ore is ground to approximately 75 microns and is dispersed into water.  Collectors selectively react with the copper particles and float, leaving the clay and other gangue minerals to waste.   Since xanthate demand depends on the ore grade, there was no way of knowing how much to put into the process.  We created a custom sensor for this application.  It turns out that wasted chemical is not the only benefit of this sensing solution.  Ore is also occasionally lost due to underdosing.  Our sensor can sense both conditions, saving the operation millions.   The sensor is in beta trials.