UNIVERSAL CALIBRATION ASSESSMENT IN AQUEOUS GEL-PERMEATION CHROMATOGRAPHY

It was the objective of this paper to assess the applicability of the universal calibration method to aqueous GPC/SEC with nonionic and anionic polymers using the Viscotek differential viscosity detector. Three water-soluble polymers-polyacrylic acid, dextran, and polyethylene oxide-were chromatographed using four Ultrahydrogel(TM) columns with 0.3 M NaCl and 0.1 M KH2PO4 as the mobile phase adjusted to pH 7. Three distinct calibration curves were obtained. Upon addition of 10% methanol, a reasonably good universal calibration curve was obtained. However, quantitative analysis of the data exhibited about 5% deviation in average M(w) and M(n) for sodium polyacrylate as calculated from the single curve as opposed to about 40% when calculated from the composite curve. The applicability of three theoretical models for the universal calibration method was assessed, and a recommendation was made for future work.