Automatic continuous-flow determination of nitrate in raw and potable waters, rivers and sewage effluents by ultraviolet absorption spectrometry

Abstract

A method for the determination of nitrate, utilising continuous-flow analysis with a dialysis membrane and ultraviolet detection, is described. The method has a linear calibration range of 0–30 µg ml^–1 of nitrate (as N) and a criterion of detection of 0.091 µg ml^–1 of N.

The incorporation of a dialysis membrane minimised the effect of humic acid type substances that did not freely diffuse through the membrane, and also avoided the necessity to filter raw and waste water samples prior to measurement.