Size-Exclusion Chromatography Using Mixed-Bed Columns with Dimethylformamide at Near-Ambient Conditions: Comparison of μstyragel Ht Linear and Pl Gel Mixed-Bed Columns

Abstract

Mixed-bed size-exclusion chromatography (SEC) columns packed with 10 μm particles are evaluated at near-ambient conditions using dimethylformamide (DMF) containing 0.01 M LiBr as the eluent. Two popular columns (HT Linear from Millipore Waters Chromatography Division and PL Gel from Polymer Laboratories) are evaluated in terms of operating pressure, resolution, fits to calibration data, and the accuracy of molecular weight distributions calculated for a broad, high-molecular-weight poly(methyl methacrylate) standard. Distinct differences in the operating characteristics between the columns are observed; however, it is shown that molecular-weight distributions comparable to those measured by SEC in a low-viscosity solvent (THF) can be obtained on both columns in DMF without the need to operate at elevated temperatures