Application report: Determination of the water content in biodiesel in accordance with ISO 12937

Biodiesel is a mixture of fatty acid methyl esters (FAME). It is obtained from vegetable oils (e.g., rapeseed, soy, and jatropha oil) and from animal fats through esterification with methanol. Minimum requirements with respect to its quality have been defined in the European standard DIN EN 14214 that has been in effect since Autumn 2003. The water content is limited in the standard to a maximum of 500 ppm. Coulometric water content determination in accordance with ISO 12937 is described here.