Analytical isotachophoresis in peptide chemistry. I. Analysis of anions in peptides.

The application of analytical capillary, carrier-free isotachophoresis as a rapid method (approx. 10-15 min per run) for the simultaneous determination of anions present in peptides (as counterion, contaminating ion or peptide anion) is described. Only small amounts of material, approx. 0.1-1.0 mg, are necessary to obtain information on the nature of the anion (qualitative) and of the amount of anion present (quantitative aspect).