<i>In Situ</i> Determination of Nitrate in Deep Sea by UV Spectrometry

Abstract

An instrument is proposed for nitrate in situ monitoring in deep sea. It consists of a UV spectrophotometer, a deuterium lamp of high stability and low power consumption, a rugged and high-throughput retro-reflection probe and a center control board with large data storage capacity. With a measurement precision of nitrate concentration of 1μmol/l and a resolution of 0.5μmol/l, the instrument is able to measure nitrate concentrations from 0.5μmol/l to 320μmol/l. The system can automatically deduct the dark current to rectify the effect of temperature drift and correct the overall absorbance drift caused by instrument drift through integration of relative absorbance (IRA) algorithm. The system can endure the pressure at up to 1500m deep sea and carry out automatic long-term in situ detection of nitrate with high stability without needs for any manual intervention.

A High-Performance Optoelectronic Sensor Device for Nitrate Nitrogen in Recirculating Aquaculture Systems

“…Numerous methods have been reported for the detection and determination of nitrate, including Cu/Cd column reduction [ 20 , 21 , 22 ], the phenol-two-sulfonic acid method [ 23 , 24 ], gas-phase molecular absorption spectrometry [ 25 , 26 , 27 ], ion chromatography [ 28 , 29 ] and ultraviolet spectrophotometry [ 30 , 31 , 32 , 33 ]. The traditional Cu/Cd column methods continue to hold a dominant position due to its low cost and easy feasibility.…”