A new class of multi-dentate ligand anchored polymeric resin has been synthesized by grafting Amberlite XAD-16 with [2-(1-Methyl-3-oxo-2-phenyl-2, 3-dihydro-1H-pyrazol-4-y1carbamoyl)-ethyl]-phosphinic acid (AXAD-16-MOPPA). The modification steps involved during the grafting process are characterized by FT-IR spectroscopy,P-31 and C-13-CPMAS (cross-polarized magic angle spin) NMR spectroscopy, CHNPS elemental analysis and thermogravimetric analysis. The influence of various physio-chemical parameters on the quantitative extraction of metal ions by the resin phase are studied and optimized by both static and dynamic methods. The developed grafted polymer shows greater selectivity for actinide ions like U(VI) and Th(IV) when compared to the lanthanides with greater distribution ratio values in highly acidic matrices. However, the lanthanides compete for the active sites in near neutral conditions. But the sorbed actinide ions and lanthanide elements can be separated by the sequential elution methodology. Moreover, the polymer exhibits faster metal ion phase exchange kinetics, where with a high sample flow rate of 25 mL min(-1) quantitative analyte sorption is achievable during the extraction chromatographic column operation for all the analytes. It also offers good ion-selectivity and greater preconcentration factor values of 400 for U(VI) and 333 for Th(IV) in 4M HNO3 conditions. The resin shows very high sorption capacity values of 1.45 mmol g(-1) for U(VI), 1.39 mmol g(-1) for Th(IV), and 1.31 mmol g(-1) for La(III) at near neutral conditions. Finally, the developed grafted resin has been successfully applied in extracting Th(IV) from matrix monazite sand which comprises large rare earth matrix, U(VI) from seawater and also U(VI) and Th(IV) from simulated nuclear spent fuel mixtures. The analytical data obtained from triplicate measurements are within 3.5% rsd, reflecting the reproducibility and reliability of the developed method.