A Simple, Low-Cost Double Beam Spectrophotometer for Colorimetric Detection of Nitrite in Seawater

Author

Gong, Weidong ; Mowlem, Matt ; Kraft, Michael ; Morgan, Hywel

Author_Institution

Nanoscale Syst. Integration Group, Univ. of Southampton, Southampton, UK

Volume

9

Issue

7

fYear

2009

fDate

7/1/2009 12:00:00 AM

Firstpage

862

Lastpage

869

Abstract

This paper reports on the optical detection system of a prototype nitrite sensor for seawater analysis. The sensor uses a colorimetric Griess reaction that produces an Azo dye with an absorption peak at 540 nm. A simple low-cost double beam spectrophotometer using a green light emitting diode (LED) light source, two integrated photo detectors and lock-in detection is described. A log-ratio amplifier is used to produce an output proportional to absorbance. The optical devices were mounted in a cast resin block to prevent shock and vibration. Experimental results show the detection system has a limit of detection of 0.1 muM.

Keywords

chemical sensors; colorimetry; optical sensors; seawater; spectrochemical analysis; spectrophotometers; Griess reaction; colorimetric detection; double beam spectrophotometer; light emitting diode; log-ratio amplifier; optical detection system; optical device; prototype nitrite sensor; seawater; seawater analysis; Absorption; Light emitting diodes; Light sources; Optical amplifiers; Optical detectors; Optical devices; Optical sensors; Prototypes; Sensor systems; Stimulated emission; Absorbance measurements; colorimetric detection; nitrite sensor; spectroscopy;

fLanguage

English

Journal_Title

Sensors Journal, IEEE

Publisher

ieee

ISSN

1530-437X

Type

jour

DOI

10.1109/JSEN.2009.2020659

Filename

5089573