A new in situ chemical analyzer for mapping coastal nutrient distributions in real time

A rapid-response, submersible chemical analyzer has been developed that is particularly suited for mapping nutrient distributions in 3-D space and time and for testing hydrodynamic models for chemical transport, within rivers, estuaries, coastal and off shore waters. The SubChemPak Analyzer/sup TM/ is a novel 3-channel reagent delivery module that transforms underwater optical instruments into sensitive chemical analyzers for rapid measurements of nutrients and other environmentally important chemicals. A family of multinutrient analyzers is being developed for selected nutrients: nitrate, nitrite, ammonia, urea, phosphate, silicate, and iron. Continuous flow spectrophotometric and fluorometric methodologies have been optimized for rapid in situ measurements of the nutrients. The operation, in situ calibration and data acquisition for the instrument are remotely controlled by a computer. The concentration readings for nutrients are instantaneously displayed on the computer monitor. The SubChemPak Analyzer may be co-deployed with standard oceanographic electronic sensor packages (CTD) for vertical and/or horizontal (to-yo) profiling.