Proposal of a new reference method for determining water content in butter oil

Determination of the relatively low water content in butter oil by desiccation methods is practically impossible. It is therefore carried out by Karl Fischer titration. To increase the solubility of butter oil in methanol, the main component of the working medium, a non-polar solvent is necessary. In an existing reference method, chloroform (trichloromethane) is prescribed. The aim of this work was the replacement of this toxic substance. It is shown that 1-octanol is a good alternative. It has the additional benefit that butter oil solubility is higher in a mixture of methanol and 1-octanol than in a mixture of methanol and trichloromethane, which conserves solvent. In addition, the sample size can therefore be higher, and this is an advantage for more heterogeneous products. The method presented is proposed as a new reference. It is also applicable to other non-polar samples.