Simultaneous quantification of methanol and ethanol in alcoholic beverage using a rapid gas chromatographic method coupling with dual internal standards

This study presented a direct GC method using dual internal standards to simultaneously determine ethanol and methanol in alcoholic beverages. The sample should only be spiked with proper amount of internal standards (100 μg 2-pentanol and 50 mg acetonitrile), and then directly injected into a mega-pore capillary column (CP-Wax 58 CB) with FID detector for GC analysis. The accurate content of ethanol and methanol in beverages could be obtained in less than 12 min. The reliability, accuracy and precision of the presented method were examined with the test of standard addition and recovery, comparison with standard methods, and the variation between intra-day and inter-day tests. All results from above tests suggested that the direct GC method presented in this study was as reliable as standard method proposed by AOAC but more rapid.