Characterization of the pore structure is a crucial part in themanufacturing of porous media used for purification of biologicalpharmaceuticals. This project took place at Cytiva in Uppsala and aimedat optimizing a newly developed method in pore structurecharacterization called size-exclusion quantification NMR (SEQ-NMR). Bymeasuring with diffusion NMR on a polymer solution before and afterequilibration with a material of interest the pore structure of thematerial can be determined. This project aimed at reducing the durationof a SEQ-NMR experiment while examining the performance of the methodduring different conditions with the goal of making the methodapplicable for quality control procedures. The method was optimizedboth by simulations and by experimental diffusion NMR measurements. Itwas discovered that the performance of the method could be improved byhaving an optimal mixture of the polymer solution and duringexperiments distributing ten measurement points with linear spacing.With these parameters optimized the duration of the method could bereduced with 22 hours landing on a total duration of 8 hours. Theduration combined with the complexity of the method still makes themethod unsuitable for use in quality control of porous media. Despitethe small possibility of SEQ-NMR being a quality control method thisproject has proven the method to be both reproducible and sensitive.