The ammonium acetate saturation (AMAS) method was used to study the cation-exchange
capacity (CEC) of zeolitic volcaniclastic materials from Santorini and Polyegos Islands, Greece. The AMAS method was tested with respect to the time required to saturate the samples of zeolites with ammonium (NH4 +) ions, the efficient liberation of NH4 + ions, and the suitability of two widely used techniques to measure ammonia (NH3) (Kjeldahl ammonia distillation technique and the ammonia electrode technique).