Determination of reducing sugars in honey, marmalades and fruit juices using a copper ion-selective electrode

Abstract

A potentiometric method for the determination of reducing sugars is described. The sample is treated with Stanley-Benedict reagent and the amount of unreacted copper(II) is determined with a copper-selective electrode by use of the standard addition method; it is then related directly to the amount of reducing sugar. Amounts of glucose in the range 0.25–2 mg have been determined with an average error of about 2%. The method has been applied to the analysis of honey, marmalades and fruit juices. The analytical recovery of glucose was 99–106%. Comparison with an official method gave satisfactory results.