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Concentration and fractionation by isoelectric trapping in a micropreparative‐scale multicompartmental electrolyzer having orthogonal pH gradients. Part 2
Author(s) -
Lim Peniel J.,
Vigh Gyula
Publication year - 2011
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.201100084
Subject(s) - electrolysis , cathodic protection , isoelectric point , chemistry , anode , fractionation , volumetric flow rate , trapping , analyte , chromatography , analytical chemistry (journal) , electrode , electrolyte , thermodynamics , organic chemistry , ecology , physics , biology , enzyme
A micropreparative‐scale multicompartmental electrolyzer called ConFrac has been developed and tested for isoelectric trapping separations. ConFrac can be operated in pass‐by‐pass mode or recirculating mode, using either asymmetrical feeding (feed enters only the anodic or the cathodic flow‐through compartment) or symmetrical feeding (feed enters both the anodic and the cathodic flow‐through compartment). Symmetrical feeding results in higher processing rates and is the preferred operation mode. Residence time in the flow‐through compartments is set as a compromise between processing rate and temperature rise in the effluent. Ampholytic components have been isolated from 5 to 50 mL volumes of micromolar feed solutions and hundredfold concentrated into 100‐μL collection compartments. Samples containing ampholytic analytes in highly conducting salt solutions were readily desalted and fractionated in ConFrac in one operation. pH transients formerly observed in other isoelectric trapping devices were observed in ConFrac as well. The pH transients were caused by the unequal ion transmission rates of the anodic‐ and cathodic‐side buffering membranes.