Standards Development

Scope

This document specifies a gas chromatographic method for ethanol, in which higher alcohols (propan-1-ol, butan-1-ol, butan-2-ol, 2-methylpropan-1-ol (iso-butanol), 2-methylbutan-1-ol, and 3-methylbutan-1-ol) from (0,1 up to 2,5) mass percentage, methanol from (0,1 up to 3) mass percentage and other impurities, in the range from (0,1 up to 2) mass percentage are determined.

Impurities are all the compounds not attributed to the groups of higher alcohols or methanol.

NOTE 1 The European ethanol blending component specification [1] sets a limit for the combined result of ethanol + higher alcohols, not the ethanol content itself.

The method is developed for non-denatured ethanol samples. With sufficient attention to correct separation of the higher alcohols and other components, determination of hydrocarbons in ethanol that contains denaturants as per EN 15376[1] is possible. Water, if present in the sample, is not included in this analysis, because a signal for water is not visible in the chromatogram. Therefore, if “alcohol content” is called up in a specification, water needs to be considered separately in the calculations.

NOTE 2 For the purposes of this document, the term “% (m/m)” is used to represent the mass percentage or mass fraction (ω).