Reference electrodes based on solid amalgams

A reference saturated calomel electrode based on the non-toxic silver solid amalgam (SCE-AgSA) as a substitute for liquid mercury is described. Long-term as well as short-term tests made during a period of one year confirmed the SCE-AgSA potential to be equal to that of SCE within the limits of +/-1 mV (the difference DeltaE(SCE-AgSA) = + 1.08 +/- 0.24 mV (vs. SCE); SD = 0.87; N = 5 1). The voltammograms of four selected metal ions registered vs. SCE-AgSA and vs. SCE could practically overlap each other. None of the mentioned electrodes were polarized to a significant degree even if the electric current applied reached 2 mA. On the basis of the obtained results the SCE-AgSA could be considered as equivalent substitute for SCE. Owing to practically identical electrode potential of both types of the mentioned electrodes the results obtained using SCF-AgSA are completely comparable to those measured vs. SCE, without any correction of peak potentials.