DETERMINATION OF ETHANOL IN BEER BY GAS CHROMATOGRAPHY (DIRECT INJECTION)—COLLABORATIVE TRIAL

Abstract

A method employing gas chromatography for the determination of ethanol in beer has been collaboratively tested by the Analysis Committee of the Institute of Brewing. It was judged that precision values were independent of concentration over the range 0.93 to 6.05% V/V ethanol. Repeatability (r95) and reproducibility (R95) values of 0.061 and 0.136 respectively, were obtained over this range. At a mean level of 9.17% V/V, the r95 and R95 values were 0.154 and 0.284 respectively. This was probably due to dilution errors as the sample had to be diluted to bring it within the linear range of the method. A comparison of the precision values given by the gas chromatographic method, with those obtained in 1991/1992 by 8 laboratories in a major brewing company using 12 sample pairs, for the IOB Recommended Distillation Method, revealed that there is no significant difference between the precision data for the two methods. 1993 The Institute of Brewing & Distilling