where 162 (g mol−1) is the molar mass of an anhydroglucose unit (AGU); 58 (g mol−1) is the net increase in the mass of an AGU for each carboxymethyl group substituted; M (in g) is the mass of dry H-CMG sample.
NCOOH (in mol) is the amount of COOH calculated from the obtained value of the equivalent volume: