An apparatus for measuring the solubility of gases in liquids at high pressures is described. The solubility of CO2, N-2 and H-2, the components from mixture ammonia syngas, was measured with this apparatus in dimethylether polyethylene glycols mixture which was obtained in our Laboratory. The Bunsen absorption coefficients and mole fractions were determined in the pressure range 0.4-4.2 MPa and the temperature range 298.15-333.15 K. The influence of the water and diisopropanolamine addition on absorption and selectivity was also studied. The results are of interest to select better solvents for the separation of the components in gas mixtures, particularly those in syngas.