Determination of calcium gluconate by selective oxidation with periodate

A modified analytical method was developed which can accurately quantitate calcium gluconate and its pharmaceutical preparations in the presence of other calcium compounds or other cations able to complex with EDTA. The proposed method was based on the principle of the Malaprade reaction, according to which gluconic acid is selectively and quantitatively oxidized by sodium periodate. The content of calcium gluconate was calculated from the amount of gluconic acid found. The selective oxidation proceeded at 50 degrees C for 10 min, yielding approximately 100% recovery of calcium gluconate. The proposed method was accurate, precise, and superior to the compendia EDTA- complexometric method in terms of specificity.