Near-infrared spectroscopy as a convenient analytical method for alkyl polyglycosides

Near infrared (NIR) spectroscopy is used for the rapid determination of decyl glucopyranoside (10G1) and alkyl polyglycoside (AG) mixtures having different alkyl chain length and the number of glucose unit in aqueous solution. NIR spectroscopy is a much simpler spectroscopic analysis method compared to three analytical methods for mixture of AGs such as thin layer chromatography (TLC), high performance liquid chromatography (HPLC), and photometry method. NIR spectra of AGs between 0.030 and 0.540 mg/ml in aqueous solutions were utilized to develop a calibration model. Both raw spectra and the second derivatives of AGs were tested for the best fit. The best calibration was built with second derivative spectra by using multiple linear regression (MLR). The standard error of calibration (SEC) and the standard error of prediction (SEP) were used for the evaluation of the model. The best calibration provides an SEP of 0.052 and 0.061 mg/ml for the prediction set of 10G1 and AG mixture, respectively.