A Potentiometric Method for Determination of Oxidized Ketone Bodies in Milk

Following the decarboxylation of acetoacetic acid by heating and the separation of acetone from milk matrix by steam distillation, acetone was allowed to react with bromine in the presence of nitric acid, causing the formation of bromoacetone and bromide; the latter was then quantified by means of a suitable ion-selective electrode applying the calibration principle. Based on checking reproducibility and on comparative analyses performed by a widely accepted photometric method, the potentiometric method developed was found to be adequate for the determination of the oxidized ketone bodies.