Determination of trace amounts of acetic acid in ethanol by fluoride isoconcentration using the method of standard additions

Abstract

The large and systematic change in cell potential resulting from the addition of 0–1%m/m of acetic acid to a solution of ethanol containing 1 × 10^–3M tetraethylammonium fluoride (TEAF) as background electrolyte, using a fluoride ion-selective electrode and a calomel reference electrode filled with lithium chloride, provides a graphical method for the rapid determination of acetic acid in ethanol. Readings obtained by direct potentiometry show good reproducibility and stability. The method, characterised by its accuracy and simplicity of operation, compares favourably with gas chromatographic methods and can be used for the determination of acetic acid in vinegar.