Quantitative analysis of binary aqueous sodium chlorate and sodium perchlorate solution in the presence of sodium dichromate using Fourier transform infrared spectrometry

Abstract

Infrared spectra of single and mixed aqueous sodium chlorate, sodium perchlorate and sodium dichromate solutions were recorded using Fourier transform infrared spectrometry. With the aid of spectral subtraction and multivariate spectral reconstruction, clear spectra of these salts, in the spectral region 900–1250 cm^–1, were obtained. The features of these spectra include maximum absorption bands at 973 cm^–1, 1110 cm^–1 and 950 cm^–1 due to chlorate, perchlorate and dichromate, respectively. In mixed solutions these salts could be detected at concentrations as low as 0.64 g l^–1. The linear dynamic range was found to be 0.2–63.8 g l^–1, 0–73.47 g l^–1 and 0–149 g l^–1 for chlorate, perchlorate and dichromate, respectively. The results obtained in the analysis of industrial samples compared well with certified values. Interference effects of different inorganic salts were studied. Sodium salts of bromide, iodate, carbonate, chloride, nitrate, and hydrogencarbonate were found to have no significant interference. Standard deviations of industrial sample determinations were found to be in the range of 2.5–4.10%.