Hydrodynamic Chromatography of Polystyrenes on Hollow Capillary Columns

A mixture of polystyrene standards with molecular weights ranging from tens of thousands to tens of millions of Da is separated on capillary columns with diameters of 2 and 5 μm. The correspondence between the experimental time of GDC elution to a universal calibration curve is investigated. It is shown that acceptable values of the C parameter of the calibration curve can be obtained only with calibration in universal coordinates. The concepts of critical molecular weight and critical elution time in GDC are introduced, and it is noted that despite the high molecular weights of the polymers that are used, their behavior is still very far from the critical point. This hinders reliable experimental determination of the C parameter. A strong drop in column efficiency in the separation of high molecular weight polymers against a backdrop of simultaneous high-efficient separation of oligomeric polymers is observed.