Use of Liquid Chromatography/Electrochemistry in Trace Determination of Phenol in Beer and in Municipal Feed Water. J. M. Dukes, G. S. Mayer, and R. E. Shoup, Bioanalytical Systems, Technical Center, West Lafayette, IN 47906. J. Am. Soc. Brew. Chem. 42:0037, 1984.

A method based on liquid chromatography/electrochemistry is capable of detecting trace amounts of phenol in finished beer, primary storage beer, and process water. Extracts from beer are prepared by being shaken with diethyl ether and back-extracting into base. If necessary, water samples are simply filtered before direct injection into the liquid chromatograph. Detection after separation is done amperometrically. Detection limits for phenol in process water were less than 100 ng/L. Because of chromatographic complexity, the minimum detectable concentrations in beers were 1-3 µg/L. Peak identification was further assisted by dual-electrode measurement, by which response ratios for unknowns can be compared to those for standards. The ratios were not statistically different. In principle, the instrumentation may be used for any phenolic substances by appropriate modification of the extraction procedures and chromatographic conditions.

Keywords: Amperometric detection, Liquid chromatography/electro-chemistry, Phenol