With each set of determinations, reagent blanks and D-glucose standards of 100 µg should be included.
The reagent blank comprises 0.1 mL distilled water + 0.1 mL sodium acetate buffer + 3.0 mL of GOPOD Reagent.
The spectrophotometer should be first zeroed with distilled water followed by reading absorbance of the reagent blank. Record the value and zero spectrophotometer again on the reagent blank - Samples & sample blanks will now be measured against reagent blank.