ANALYSIS OF BIOLOGICALLY ACTIVE PEPTIDES USING TWO-DIMENSIONAL HPLC-CE

High-performance liquid chromatography (HPLC) is a technique most frequently used for the assess- ment of biologically active peptides. Owing to the ionic character of these compounds, they may also be sepa- rated and assayed using capillary electrophoresis (CE), which offers very high efficiency, short analysis time and low consumption of reagents, and is used increasingly more often. The paper describes the combination of HPLC and CE in order to increase the efficiency of the separation of complex mixture of peptides (active sub- stance and its related impurities). The developed two-dimensional HPLC-CE technique was employed for the analysis of the impurities of octreotide, a cyclic octapeptide used in therapy. Because distinct separation mech- anisms are used, the two-dimensional technique ensures higher separation efficiency and a more comprehen- sive impurity profile of the medicinal product than either of the techniques used separately.