A submersible battery-powered flowinjection (FI) sensor for the determinationof nitrate in estuarine and coastal waters

摘要

The design, construction and performance of a remotely deployedsubmersible flow injection-based nutrient (total oxidized nitrogen)sensor are described. The sensor featured a custom-built microcomputerand a solid-state, flow-through spectrophotometric detector,and the derivatization chemistry was based on in-line coppercadmiumreduction of nitrate to nitrite, and diazotization withN1NED and sulphanilamide. The limit of detection was0.0014 mg l-1NO3-N and the linear range was 0.0014-0.77 mg l-1with a 260 μl sample volume and a 20 mm pathlength flow cell. Results from submersed deployments in the Tamarestuary and North Sea are also reported.