Characterization of Methanol in White Spirits Based on Two-Dimensional Infrared Correlation Spectroscopy

The aim of present work is to develop an innovative and alternative method for the identification and quantification of methanol in white spirits based on twodimensional (2D) infrared spectroscopy. Firstly, for the identification and quantification of methanol in white spirits, 19 white spirits samples adulterated with different levels of methanol (0.1% to 10%) were prepared. And, the Fourier transform one-dimensional (1D) infrared spectra of all samples were measured at room temperature. Secondly, spectral characteristics of white spirits adulterated with methanol were studied by 1D infrared spectra and 2D infrared correlation spectra. Then, the origin of 1020 cm-1 peak of methanol was verified in terms of the existence or not of cross peaks in synchronous and asynchronous 2D infrared correlation spectra. Finally, The calibration curve was established based on the auto-peak intensity at 1020 cm-1 in synchronous 2D infrared spectra and methanol concentration in white spirits. The coefficient of determination was 0.995. The proposed method can provide a new and fast detection technique of methanol in white spirits, and also be applied to other food safety detection areas.