Simplification of the Colorimetric Method to Detect Methanol Contamination in the Cambodian Local Rice Liquor

Abstract

Methanol, an alcohol, is known to be hazardous for human consumption. Methanol contamination in traditional rice liquor caused many deaths in local areas in Cambodia. Contamination happened in every step of liquor manufacturing, distribution, and consumption. To avoid this problem, monitoring the quality of alcohol is important. However, only a few government institutes in the capital can detect the methanol contamination at an institutional level by colorimetric methods. To detect methanol contamination easily at the local level, a simplified method is urgently required. We tested the original colorimetric methods to determine the influence of the amount of chemical solutions, the time and the alcohol percentage to the color change. Further we checked the shelf life of the chemical solutions. The results showed that methanol was detectable at one-twenty of original volume after treatment 2-5 hours, and the alcohol percentage was not influence of the color changes. In addition, we tested 21 liquor samples collected from markets in Phnom Penh and 6 provinces with the simplified method, resulting that methanol was not detected in all samples.