Standardization Method for Molecular Weight Cut-off Evaluation of Ultrafiltration Membranes. V

Measurement of Molecular Weight Cut-Off Using GPC Analysis Method for Hollow Fiber Membrane

Abstract

The purpose of this work was to develop a standard analytical technique for determining solute concentrations in a retention characterization of hollow fiber ultrafiltration (UF) membranes. Six commercially available membranes were selected. The solutes used were three polyethylene glycols (PEG) of different average molecular weights of 7500, 20000, and 50000 and four dextrans (DEX) of different average molecular weights of 10000, 38800, 72200, and 539000. The experiments were done under the following conditions : 10-30 kPa of transmembrane pressure, (TMP), 0.22-0.32 m/s linear velocity, (u), and 300-4500 mg/l feed concentration, (C). The solutions with a single molecular weight solute were analyzed by a TOC analyzer, and a GPC analyzer was used for mixed molecular weight solutions.
The molecular weight cut-off characteristics as determined by the GPC analysis method for mixed molecular weight solutions agreed well with the TOC analysis method for single molecular weight solution. In addition, DEX and PEG solutions gave similar results, and concentration _appeared to have a negligible effect.