Rapid quality control of industrial flocculents using Fourier transform mid-infrared spectra and multivariate analysis

This study aimed to use the Attenuated Total Reflectance-Fourier transform mid-infrared (ATR-FTIR) spectroscopy coupled with chemometrics, as an alternative method for the qualitative-quantitative determinations of flocculent quality. To the best of our knowledge, there is no work that has treated the properties of flocculants by direct spectroscopic methods. The quality of the flocculent was ensured by the determination of two parameters namely, sedimentation rate (VS) and solid rate (TS), during the coagulation/flocculation process. Firstly, spectral and reference data of 36 samples from three different lots of flocculent, were analyzed by principal component analysis (PCA), Partial Least Squares Regression (PLSR) and results were used to establish calibration models. PLSR models revealed the best calibration models for predicting VS and TS values for studied samples, with the coefficient of determination (R2) of 0.99. In addition, cluster analysis (CA) and linear discriminant analysis (LDA) were adopted as differentiation methods of studied samples. On the basis of CA, three distinctive clusters were recognized. The model built by LDA could classify the samples with an accuracy value of 100%. Hence, it can be concluded that ATR-FTIR spectroscopy combined multivariate analysis can be used for the rapid prediction of flocculent quality. •FTIR spectroscopy used to quality control of flocculents.•PLSR models revealed the best calibration models with the coefficient of determination (R2) of 0.99.•Infrared spectroscopy combined multivariate analysis can use for a rapid prediction of flocculent quality.