Isotachophoretic separation of middle molecule peptides in uremic body fluids

By applying analytical isotachophoresis six solutes in the middle molecule range were isolated as a further separation of a middle molecule fraction isolated from uremic body fluids using an earlier described technique of combined high speed gel filtration--gradient elution chromatography. The solutes separated with isotachophoresis could be identified by determining the net mobilities and the corresponding UV levels. Identical net solute mobilities were found in different biological fluids from different uremic patients. By measuring the zone length it was possible to estimate the amounts of material present in uremic biological fluids. During these investigations the reproducibility was better than +/-2% for the six solutes measured.