IP 571: Ethanol as a blending component for petrol - Determination of higher alcohols, methanol and volatile impurities - Gas chromatographic method

Overview:

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.

NOTE 1 The European ethanol blending component specification, EN 15376, 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 is possible.

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