The MEA-DEAB-CO2-H2O solutions contain complex ions in the solution. Carbamate (RNH-COO-) and bicarbonate (HCO3-) anions are the major format of CO2 dissolved in the solutions. The ion concentrations of both components are constrained by the reaction equilibrium and VLE model of CO2-amine interactions. For the MEA-CO2-H2O systems, the majority of [CO2]0 is carbamate. For the DEAB systems, the majority is bicarbonate. The blended amine system such as MEA-DEAB-CO2-H2O contains both carbamate and bicarbonate at different ratios, which is affected by variations of amine ratio, CO2 loading and operation temperatures. This work summarized VLE plots from 13C NMR analysis of single and blended amine solutions, both in room temperature (24°C) and higher temperature (70°C) to detect trend of the ratio of bicarbonate vs carbamate in the blended amine (MEA-DEAB) systems under both absorption and regeneration conditions. These experimental data indicated the carbamate exchange reaction is endothermic. With increase of temperature, ratio of bicarbonate increased accordingly and that of carbamate decrease. The increased concentrations of bicarbonate can facilitate the amine regeneration with reduced heat duty.