Ag/AgCl and SCE reference electrodes are generally not advised for use in alkaline media because silver and mercury turns into oxides (yellow color shift in the filling solution can be noticed) which leads to reference electrode instability and drastic change in the electrode potential.
One conventional way for using Ag/AgCl and SCE reference electrodes in an alkaline medium, which is using a Luggin capillary (It should be filled with either KCl or K2SO4).
