An embodiment provides a method for measuring a characteristic of an aqueous sample, including: introducing the aqueous sample to a titration region and a reaction region of a measurement device, wherein the titration region comprises a pH electrode and a protonator electrode contacting a first portion of an aqueous sample, wherein the reaction region comprises a counter electrode contacting a second portion of the aqueous sample; placing an electrolyte reservoir in a state of electrical continuity with the titration region and the reaction region, wherein the electrolyte reservoir comprises a reference electrode, wherein the volume of the electrolyte reservoir comprises a large volume of an electrolyte; and determining a characteristic of the aqueous sample by measuring an electrochemical characteristic between the reference electrode and at least one of: the pH electrode and the counter electrode. Other aspects are described and claimed.