Key words: adsorption, impregnation, supercritical fluid, N,N,NАК,NАК-tetraoctyl diglycolamide, solid phase extraction
In this study, the adsorption isotherms of N,N,N’,N’-tetraoctyl diglycolamide (TODGA) on three types of hypercrosslinked polystyrene (HCP) in supercritical CO2 were measured by gravimetric analysis. It is shown that under equal conditions (T = 313.15 K, P = 20 MPa), MN200 and MN202 HCPs adsorb up to 0.55 mmol/g and 0.59 mmol/g TODGA respectively, which allows them to be applied as the ligand carrier. The adsorption of TODGA on MN270 under the same conditions did not exceed 0.07 mmol/g. Also the temperature and medium density effect on the TODGA adsorption on MN200 was evaluated. It is shown that isothermal decreasing of the CO2 density can increase the saturated adsorption of TODGA. The solid phase extractant (SPE) based on MN202 and TODGA did not show extraction properties towards Nd3+, which is probably due to the matrix insufficient pore size for the formation of comparatively large complex compound. At the same time, SPE based on MN200 showed a potential feasibility of its use.
doi:10.34984/SCFTP.2023.18.2.005