A feasibility study on quantitative analysis of low concentration methanol by FT-NIR spectroscopy and aquaphotomics

Abstract Methanol content is a key parameter in the fermentation industry. However, the methanol concentration during fermentation is usually quite low, it's necessary to find a method to measure methanol with low content, even indirectly. Near infrared spectroscopy (NIRS) technology is rapid and non-destructive, which can provide analytical solutions for components that represent approximately 1%. Aquaphotomics gives the chance to dig into the information remaining hidden in the NIR spectra, which shows a distinct advantage if the target object is presented in lower concentrations. Therefore, NIRS combined with aquaphotomics was introduced in this study to prove the feasibility for methanol determination at 0.1%–2.5% ( v / v ) in aqueous solutions. Determination coefficient of calibration (R 2 c ), validation (R 2 p ) and cross validation (R 2 cv ), root mean square error of calibration (RMSEC), validation (RMSEP) and cross validation (RMSECV) were applied to verify the performance of the partial least squares regression (PLSR) models, and the corresponding values of best model were 0.999, 0.999, 1.000, 0.0204%, 0.0277%, 0.0142%, respectively. Our successfully result indicated that NIRS technique combined with aquaphotomics may open a new perspective in methanol determination.