Abstract: Near-infrared spectroscopy was used to establish a fast and nondestructive method for determining excess methanol in liquor. A model in the range of 4360–4460 cm-1 that allows the rapid and nondestructive identification of methanol concentrations exceeding 0.1% (0.0791 g/100 mL) was developed using partial least square (PLS) regression based on the acquired transmission spectra in the range of 4000–5200 cm-1 of experimental liquor samples adulterated with different concentrations of methanol. The developed model showed a correlation coefficient of 0.999, a RESEC value of 0.062 and a prediction precision of 0.1%. Therefore, near-infrared spectroscopy can be used for market screening of adulterated commercial liquors as a fast and nondestructive detection technique.

Key words: near-infrared spectroscopy, partial least square regression, fast, nondestructive