An In-situ, Biogeochemical Sensor using Excitation-Emission Matrix Fluorometry

The technical, scientific, and commercial feasibility of developing a novel aquatic in-situ biogeochemical sensor, termed the XMF, is evaluated. Using excitation-emission matrix fluorometry, the sensor will enable in-situ simultaneous detection and effective analytical separation of individual biogeochemical components present in seawater, including humic substances, hydrocarbons, proteins, wastewater/sewage, and other natural and anthropogenic substances. Excitation-emission matrices (EEMs) will be measured at sampling rates on the order of a second. No scanning of the monochromators, in fact no moving parts whatsoever, will be required. The technological innovation making this possible is termed Double Dispersion Imaging (DDI). The sensor software will incorporate real-time, automated quantum corrections and 2-D mixing analysis techniques. Design goals emphasize portability, compactness, ruggedness, and enabling flexible deployment through features such as variable sampling rates and memory storage capabilities. No current sensor for oceanographic deployment has these characteristics. If feasibility is demonstrated, the XMF is expected to be a powerful analytical tool for investigating biogeochemical processes that we feel will realistically mark a turning point in the analytical oceanic measurement capabilities.