Quantitative Analysis of Chromium(VI) in Dilute Solution by Using Adsorption and Diffuse Reflectance Near‐infrared Spectroscopy

Abstract

A method for quantitative determination of metal element in aqueous solution was developed by using adsorption and diffuse reflectance near-infrared spectroscopy (DRNIRS). In this method, the analyte is firstly adsorbed onto the resin from the dilute solution, and then the adsorbed analyte is directly determined in the sorbent by using DRNIRS. Enrichment of the analyte is achieved by the adsorption from the dilute solution, and quantitative determination is accomplished by using multivariate calibration technique. Taking chromium(VI) in river water as the analytical target, adsorption conditions and the partial least squares (PLS) model was optimized. The results show that chromium(VI) can be immobilized onto the adsorbent and quantitatively measured by DRNIRS and multivariate calibration. With cross validation and external validation, the correlation coefficient between the reference and predicted concentration was found to be above 0.98 in the range of 0.75-29.90 mg•L -1 for the PLS model, and the interference of the coexisting matrix was eliminated with the aid of multivariate calibration.

Determination of Bilirubin Using near Infrared Diffuse Reflectance Spectroscopy with Selective Concentration on β-Cyclodextrin

“…1,2 For improving the practicability of NIR spectroscopy, chemometric methods have been developed for quantitative analysis since NIR spectra are commonly composed of weak, broad and overlapping peaks. [3][4][5][6] At the same time, experimental efforts have been devoted to enhancing the sensitivity of NIR spectroscopic analysis. Preconcentration is one of the most frequently used techniques for the determination of microcomponents.…”