Determination of reducing sugar with improved precision

The neocuproine test as described by Brown (4) has been modified to include the range of 5 to 125 μg of glucose. The replacement of the tartrate chelating agent by glycine reduces the value of the blank and decreases the relative standard error of the conventional oxidation procedure by a factor of approximately 6 at low substrate concentrations and by a factor of 2 at high substrate concentrations.