b'CHALLENGES OF NITRATE MONITORINGDr. Smith clarified that water quality professionalswant to measure nitrate directly in our waterways,but it just isnt that easy.Nitrate monitoring in the field has always been a desired thing, but its not been easy to do. Its kind of like coliform testing. It would be awesome if we could just have a real-time view of coliform pollution at our beaches. Well, its hard to do, she said. Nitrateand other parametershave been measured with relative ease in lab settings for decades, but these methods arent always field-friendly. One of our biggest challenges with water quality monitoring, in general, is instead of building a technology for the field, weve always tried to adapt a lab technology to be used in the field. I think were all starting to appreciate that doesnt work very well. Unlike in the lab, you cant control sample preparation in the field, added Dr. Smith.ISSUES WITH TRADITIONAL NITRATE MEASUREMENT TECHNOLOGIESNitrate ion-selective electrodes (ISEs) are available for many water quality platforms, including the YSI ProDSS and EXO. These sensors have a membrane that specifically targets the nitrate ion, but there are issues with using nitrate ISEs in the field, such as interferences.Nitrate ISEs are a great example of a lab technology weve tried to use in the field. But were measuring in the real world, not a controlled setting. There are all kinds of variables to consider, Dr. Smith pointed out. Luckily, another type of nitrate sensor is better suited for the field. 44 MISSION: WATER'