Large sample volume preseparation for trace analysis in isotachophoresis.

An isotachophoretic device for the analysis of trace components in a sample with the efficient pre-separation and elimination of bulk components has been suggested and realized. A large volume of the sample in question is separated in a rectangular wide-bore channel packed with a suspension of a granulated polyacrylamide gel and analyzed in free electrolytes in a narrow-bore tube. Trace components, the concentrations of which are 10(-6) mol/l, can be analyzed in 60-70 min applying ca. 1 ml of the sample even in the presence of bulk excess of a major component the concentration of which is by 5 orders of magnitude higher.