Using Raman Spectroscopy for Determination Methanol Quantity in Illegal Alcoholic Beverages

Illegal production of alcoholic beverages is a common problem in most countries.The consumption of these counterfeit alcoholic products in Turkey has increasingly been one of the major health concerns.In this study,a comparison between GC-MS and Raman spectroscopy techniques was made to determine the amount of methanol in BogmaRaki which is a counterfeit alcoholic beverage produced and consumed in Hatay region.Different ratios of methanol/ethanol concentrations were prepared to obtain a calibration curve.This curve was used to measure the amount of methanol in the actual product samples using both GC-MS and Raman spectroscopy techniques.Results obtained from both techniques were compared using Paired sample t-tests.The Limit of Detection and the Limit of Quantification values were determined as 0.03(%v/v) and 0.11(%v/v),respectively.Both techniques demonstrated a similar sensitivity in the determination of methanol concentration in these counterfeit products(p>0.05).Raman Spectroscopy,however,has an advantage of being easy to use,inexpensive,rapid and non-destructive analytical technique with little or no sample preparation.