A rapid enthalpimetric method for the assay of the reducing sugar content of some soft drinks

An enthalpimetric method for the rapid, low cost assay of reducing sugars in soft drinks is reported. The assay involves the determination of the sugars by oxidation with copper(III) ions in an alkaline medium. Separation of the various matrix materials, fruit peel, preservatives, etc. is not required. Amounts of glucose in the range 12.5–50 mg per litre of sample have been determined with an average error of 1.5%. The time of assay is less than 2 minutes. The method is capable of being automated for use with semi-skilled operatives. The proposed method has been compared with the Official Method and the results are equally acceptable. The advantages of the proposed method include speed of assay, the potential for automation and the low cost of individual assays.