Operation of amine plant for CO2 removal had long been plagued with inefficiencies due to suboptimal operating parameter leading to losses in operational expenditure. Improving the system requires understanding into thermodynamics and kinetics of the process which can be made possible through having information on the qualitative and quantitative speciation in the alkanolamine system. In this work, potential of Raman spectroscopy as a monitoring tool for species concentration in CO2-loaded aqueous monoethanolamine (MEA) system was investigated. CO2 loading data from experimental work were used with Kent Eisenberg model to estimate species concentrations (dissolved CO2, Protonated amine, Bicarbonate, Carbonate, Carbamate and unreacted MEA). Each species concentration were fitted to experimentally-acquired Raman spectrum using Partial Least Square Regression (PLSR) technique to develop calibration model. Evaluation of regression plots, R2 and Root Mean Square Error (RMSE) shows good predictive accuracy compared to the thermodynamically-predicted species concentration. © 2020 IOP Publishing Ltd.