Rapid and selective quantitative colourimetric analysis of nitrite in water using a S-Nitrosothiol based method

E Latvyte; A Greenwood; A Bogush; J E Graves

doi:10.1016/j.wroa.2024.100265

Rapid and selective quantitative colourimetric analysis of nitrite in water using a S-Nitrosothiol based method

Water Res X. 2024 Oct 11:25:100265. doi: 10.1016/j.wroa.2024.100265. eCollection 2024 Dec 1.

Authors

E Latvyte¹, A Greenwood², A Bogush³, J E Graves¹

Affiliations

¹ Centre for Manufacturing and Materials, Coventry University, Beresford Avenue, Coventry, UK.
² School of Life Sciences, Coventry University, Whitefriars Street, Coventry, UK.
³ Centre for Agroecology, Water and Resilience, Ryton Organic Gardens, Coventry, UK.

Abstract

This study introduces a novel S-nitrosothiol based method for the rapid and highly selective detection of nitrite in complex water matrices. Sodium 3-mercapto-1-propanesulfonate forms a distinctive pink S-nitrosothiol compound upon interaction with nitrite in acidic media, allowing both visual and quantitative detection. Various factors affecting the absorbance of the final product were investigated, including pH, reaction time, acid type, and sodium 3-mercapto-1-propanesulfonate concentration. UV-Vis spectrophotometric analysis demonstrated an excellent linear correlation (R² = 0.99) across a broad detection range (0.05 to 80 mmol l^-1), while showing no interference from common ions such as nitrate or dissolved organic matter, a limitation frequently observed in conventional UV-based nitrite detection methods. The assay was further adapted into a pellet form to simplify field use, operating effectively at room temperature with a low detection limit (1.4 ppm). The S-nitrosothiol based method represents a safer and more environmentally friendly option for nitrite detection and shows a promising potential as a valuable addition to both field and laboratory water testing kits for nitrite analysis.

Keywords: Colourimetric detection; Nitrite; Wastewater; Water analysis.