Determination of nitrate in municipal waste water by UV spectroscopy

A method is proposed in which diode-array UV-visible spectroscopy and multivariate data analysis are applied to determine nitrate in municipal waste water. No filtering of the samples is required and no reagents are added. The working range for the nitrate determination is 0.5–13.7 mg/l (0.008–0.22 mM). The relative standard deviation was found to be 3.4%. Other constituents, notably total phosphorus, total nitrogen, ammonium nitrogen and iron can be determined simultaneously with the same method. The developed method can also be used to classify samples. The described method concept is well suited for in-line monitoring.