Rapid low-level nitrate determination by UV spectroscopy in the presence of competing ions

Abstract

The presence of excessive nitrate in environmental and drinking water even at low levels can pose both environmental and health hazards. Because of this, various methods for its removal have been investigated. Essential to conducting such research is a method to reliably quantify nitrate in relevant matrices. However, current approaches have drawbacks related to cost, analysis time or health hazards. This study evaluates a UV spectroscopy-based method for nitrate determination, suitable for quantifying low nitrate concentrations in the presence of bicarbonate, sulfate, chloride and phosphate. The limits of detection and quantification were found to be 0.003 ppm N and 0.0077 ppm N respectively, lower than that observed in the ion chromatography method it was compared to. Additionally, a calibration curve created with 11 standards ranging from 0 to 2.5 ppm N demonstrated an exceptionally strong correlation, with an R² value greater than 0.9999. This method is developed with a focus on accessibility and speed, minimising hazards and waste generation for reduced environmental footprint. The effects of contaminants introduced through the use of commercial laboratory consumables are also discussed.