University Of Tasmania

File(s) under permanent embargo

An automatic gas-phase molecular absorption spectrometric system using a UV-LED photodiode based detector for determination of nitrate and total nitrate

journal contribution
posted on 2023-05-18, 14:33 authored by Zhang, M, Zhang, Z, Yuan, D, Feng, S, Liu, B
An automatic gas-phase molecular absorption spectrometric (GPMAS) system was developed and applied to determine nitrite and total nitrate in water samples. The GPMAS system was coupled with a UV-light emitting diode photodiode (UV-LED-PD) based photometric detector, including a 255 nm UV-LED as the light source, a polyvinyl chloride (PVC) tube of 14 cm as the gas flow cell, and an integrated photodiode amplifier to measure the transmitted light intensity. The UV-LED-PD detector was compact, robust, simple and of low heat production, comparing with detectors used in other GPMAS works. For nitrite measurement, citric acid was used to acidify the sample, and ethanol to catalyze the quantitative formation of NO2. The produced NO2 was purged with air flow into the UV-LED-PD detector, and the gaseous absorbance value was measured. The total nitrate could be determined after being reduced to nitrite with a cadmium column. Limits of detection for nitrite and nitrate were 7 μmol/L and 12 μmol/L, respectively; and linear ranges of 0.021–5 mmol/L for nitrite and 0.036–4 mmol/L for nitrate were obtained. Related standard deviations were 1.81% and 1.08% for nitrite and nitrate, respectively, both at 2 mmol/L. The proposed method has been applied to determine nitrite and total nitrate in some environmental water samples.


Publication title









School of Natural Sciences


Elsevier Science Bv

Place of publication

Po Box 211, Amsterdam, Netherlands, 1000 Ae

Rights statement

© 2011 Elsevier B.V. All rights reserved.

Repository Status

  • Restricted

Socio-economic Objectives

Natural hazards not elsewhere classified

Usage metrics

    University Of Tasmania