A rapid and accurate method for determination of methanol in alcoholic beverage by direct injection capillary gas chromatography

To directly determine methanol content in alcoholic beverages a simple and rapid method using polar megapore column (CP-Wax 58 CB, 30 m×0.53 mm) is presented. With acetonitrile as internal standard, chromatogram showed a retention time of 3.06 min for methanol and 4.21 min for internal standard. The linear range of the calibration curve for methanol was wide, ranges from 2.0 μg/mL to 20 mg/mL (r2=0.999). Standard addition of methanol to wine and whisky lead to excellent recoveries of 101–107% and 94–103%, respectively. Examining coefficients of variation and relative errors obtained from repeated analyses in a range of concentrations (50–1000 μg/mL), this method was found to display high precision and accuracy. With this method, no pre-treatment of samples was required and it took less than 9 min for one single analysis from direct injection of original samples to obtaining data.