Normalized Nitrite-Nitrate UV-Vis Absorbance Dataset

This dataset provides normalized ultraviolet\u2013visible (UV\u2013Vis) absorbance spectra of nitrite\u2013nitrate mixtures acquired for water quality analysis. Standard solutions of nitrate (0\u2013200 ppm, 10 ppm increments) and nitrite (0\u20133.0 ppm, 0.1 ppm increments) were prepared and combined to form mixed samples representative of realistic aquatic conditions with spectral interference. Absorbance measurements were collected using an Agilent Cary 60 UV\u2013Vis spectrophotometer operated at a slow scan rate of 200\u2013300 nm\/min over the wavelength range of 190\u2013440 nm, with a spectral resolution of 1 nm. The resulting dataset captures the characteristic ultraviolet absorption behavior of nitrate and nitrite while preserving subtle nonlinear interactions between overlapping spectra. This dataset is suitable for developing and benchmarking machine learning and symbolic regression models for reagent-free nitrate and nitrite quantification, particularly in embedded or real-time water monitoring applications.