Study of surface-enhanced Raman spectroscopy combined with green catalytic derivation scheme for the determination of methanol in alcoholic beverages

There are two main challenges in completing the surface-enhanced Raman spectroscopy (SERS) detection. One is the small Raman scattering cross section of methanol and the other is the derivatization strategy. They were solved by coupling the catalytic strategy with a thermal purge separation and enrichment device. In this study, the quantitative analysis of methanol in alcoholic beverages was performed as methanol was catalyzed to formaldehyde. For detecting methanol in low alcoholic beverages, the acetaldehyde derivatives generated by the interaction of ethanol-catalyzed oxide acetaldehyde with 3-Methyl 2-benzothiazolinonehydrazone Hydrochlide Hydrate (MBTH) during the catalytic process will not cause large interference with the SERS signal of formaldehyde. In this case, the MBTH with higher sensitivity is selected for the derivatization operation. In the analysis of methanol in high alcoholic beverages, acetylacetonate derivatization without interaction with acetaldehyde was used to avoid the interference of acetaldehyde generated from ethanol. Based on the detection of formaldehyde in methanol standard solutions, methanol was detected in wine and sake as well as in high-alcohol beverages. Thus, a convenient and rapid method was achieved for the detection of methanol in alcoholic beverages.