Testing the permeability of porous membranes using High Performance Liquid Chromatography (HPLC) and photometry

Abstract

An experimental setup was developed to characterize the permeability of various molecules through porous polymer membranes. Two porous polyurethane membranes with porosities of 30% and 50% were investigated besides an ePTFE (expanded polytetrafluoroethylene) membrane as a reference. Methylene blue and insulin were used as analytes to evaluate molecule transport. Due to its intrinsic coloration, methylene blue enabled visual detection of membrane passage, while quantitative analysis was performed photometrically at 665 nm. Insulin concentrations were determined by High Performance Liquid Chromatography (HPLC) with detection at 214 nm. Methylene blue migrated through all three membrane types, while insulin, due to its larger molecular size, was only detected when passing through the polyurethane membrane with 50% porosity.