Liquid chromatography of polymers under limiting conditions of adsorption: III. Role of experimental variables.
LC of polymers under limiting conditions of adsorption (LC LCA) is a novel method based on different mobility of (pore excluded) macromolecules compared to (pore permeating) solvent molecules. Polymer sample is injected in a solvent preventing its adsorption within the column. Eluent promotes sample adsorption. Under these conditions, macromolecules cannot leave its initial solvent and elute from the column independently of their molar mass. In contrast, a less interactive simultaneously injected polymer leaves its initial solvent zone and is eluted in the size exclusion mode. As a result, chemically different polymer species can be discriminated. The effect of selected experimental conditions was studied on the LC LCA behavior of poly(methyl methacrylate)s eluted from bare silica gel columns. The parameters were packing pore diameter, injected sample volume and concentration, as well as column temperature. The size independent elution was only little affected by the above parameters and LC LCA produced well-focused peaks. The LC LCA mechanism was operative even at a very large sample of both volume and concentration. This makes LC LCA a robust and user-friendly method, likely suitable also for characterization of minor components of polymer mixtures.
Snauko
Marián
M
Laboratory of Liquid Chromatography, Polymer Institute, Bratislava, Slovakia.
Berek
Dusan
D
D000327:Adsorption; D002853:Chromatography, Liquid / Q000295:instrumentation / Q000379:methods*; D011108:Polymers / Q000302:isolation & purification*; D013696:Temperature
D011108:Polymers