Study on Nitrite Nitrogen Based on Ultraviolet Visible Absorption Spectrometry

Abstract

In order to improve the accuracy of nitrite nitrogen detection, this template proposed a method for rapid determination of nitrite nitrogen in water based on ultraviolet visible absorption spectroscopy. The experimental object is the absorption spectrum of sodium nitrite standard solution with a concentration range of 0.1 to 17 mg·L-1, the continuous projection algorithm SPA (Continuous Projections Algorithm) is used to screen out the characteristic wavelengths related to nitrite nitrogen. the absorbance at the characteristic wavelengths and the sample concentration are fitted using Support Vector Regression (SVR) to establish a regression model for nitrite nitrogen, The decision coefficient R2 and root mean square error RMSE are used as the evaluation indicators of the model. The experiment found that the R2 and RMSE of the mixed prediction model established using the continuous projection algorithm support vector regression (SPA-SVR) modeling method were 0.999654 and 0.000479 mg·L-1 respectively, and their modeling effects were better than those of the three mixed prediction models, KPCA-SVR, PCA-SVR, and Lasso-SVR, achieving rapid and accurate measurement of nitrite nitrogen.