Simultaneous Determination of Methanol and Ethanol Content in Traditional Chinese Jujube Brandy

摘要

The simultaneous determination of the methanol and ethanol content in traditional Chinese jujube brandy, a simple and rapid method using GC-FID equipped with a semi-polar column (TG-35MS, 30 m x 0.25 mm x 0.50 um) is presented. Chromatogram showed a retention time of 6.73 min for methanol and 7.38 min for ethanol. The linear ranges of the calibration curve for methanol and ethanol were both wide, range from 31.25 μg/100 mL to 3.20 g/100 mL for methanol (R~2= 0.9995) and 1.25 to 80 % v/v for ethanol (R~2= 0.9969). Standard addition of methanol and ethanol to traditional Chinese jujube brandy gained excellent recoveries of 101.8 and 101.3 %, respectively. With this method, pre-treatment of sample is no longer required and less than 19.10 min is taken for one single analysis from direct injection of original samples to obtaining data. Twenty-four samples of traditional Chinese jujube brandy were detected with this method. The results showed that all samples had a high average ethanol content of 53.4 + 8.4 % v/v, while the average value of methanol content (in 60 % ethanol) was 0.40 + 0.09 g/100 mL.