Team:USP-Brazil/Solution

The Solution

Detection of Methanol in Alcoholic Drinks

Methanol, when present in alcoholic drinks, even when it is not intentionally added to lower production cost, is a metabolic product of the degradation of fruit organic residues [2]. Analytical chemistry methods for methanol detection in ethanol solutions have been developed since late nineteenth century. The most common is Chapin's colorimetric method, currently, it is required by an ISO rule [3][4] in ethanol-producing industries. Most methanol detection devices rely on highly specific equipment and techniques, such as infrared spectroscopy, liquid and gaseous chromatography [5]. There are also chemical methods [6], but no alternative suitable for the scale of the problem, once they all are too elaborate and expensive, whether because of the equipment, or because of the chemical reagents. A problem as global as this needs a solution that is cheap, user-friendly and scalable.

The greatest advantage of a biochemical sensor could be, in addition to accessibility and easy use, its production: once the microorganism that has been modified to act as a detector is built, cell culture growth is itself responsible for producing the detector. This not only simplifies the process, but it also reduces its cost: the only expenses after the development and construction of the biosensor would be with culture media and with preparing the product (e.g. lyophilization and transport device).

Bottlenecks

The difficulties faced in methanol detection consist in two categories: accessibility and efficiency. Methanol analysis today is still expensive, at a mean price of 58 USD [1], which is too high for noncommercial producers. Also, most populations exposed to methanol intoxication have no access to chromatography equipment, to the reagents necessary for analysis, nor to the technical knowledge involved. Also, time and efficiency play a major role: the fastest tools take up to a week to return their results [1], and usually provide information that is useless to the producer—once the main concern is whether the drink is safe. Essentially, there is no method developed for individual, small-scale producers: only for the companies that can afford cutting-edge tools.

Back to the problem See the Detector

References

[1] AJA van Maris et al. Alcoholic fermentation of carbon sources in biomass hydrolysates by Saccharomyces cerevisiae: current status. Antonie Van Leeuwenhoek, vol 90: 391–418 (2006).

[2] B Schink and JG Zeikus. Microbial Methanol Formation: A Major End Product of Pectin Metabolism. Current Microbiology, vol. 4: 397-389 (1980).

[3] FR Georgia and R Morales. Detection of Methanol in Alcoholic Beverages. Industrial and Engineering Chemistry, vol. 18, nº 3 (1921).

[4] Norm ISO 1388-8:1981 http://www.iso.org/iso/catalogue_detail.htm?csnumber=5950

[5] K Sharma et al. Novel Method for Identification and Quantification of Methanol and Ethanol in Alcoholic Beverages by Gas Chromatography-Fourier Transform Infrared Spectroscopy and Horizontal Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy. Journal of AOAC International, vol. 92, nº 2 (2009).

[6] W Zhang et al. Fermentation Strategies for Recombinant Protein Expression in the Methylotrophic Yeast Pichia pastoris. Biotechnol. Bioprocess Eng. vol 5: 275-287 (2000).

[7] FIGARO TGS 822 - for the detection of Organic Solvent Vapors http://www.figarosensor.com/products/822pdf.pdf

[8] W Zheng et al. A Rapidly Responding Sensor for Methanol Based on Electrospun In2O3-SnO2 Nanofibers. J. Am. Ceram. Soc. vol 93[1]: 15-17 (2010).

[9] AJ Paine and AD Dayan. Defining a tolerable concentration of methanol in alcoholic drinks. Human & Experimental Toxicology, vol. 20: 563-568 (2001).