CAPILLARY ZONE ELECTROPHORESIS MASS-SPECTROMETRY AS A TOOL IN THE STABILITY RESEARCH OF THE LUTEINIZING-HORMONE-RELEASING HORMONE ANALOG GOSERELIN

A capillary zone electrophoresis (CZE)-MS system for peptide analysis was developed, characterised and applied in the stability research of goserelin, a luteinising hormone-releasing hormone analogue. 10% aceti c acid was used as running solution. An important aspect of this CZE-M S system is its relative insensitivity to injection volume size and io ns in sample solutions, As a result of the low pH (2.3) of the running solution, the endoosmotic flow was minimal, resulting in mainly elect rophoretic movement and, therefore, relatively high resolution. Degrad ed samples of goserelin at pH 5 and 9 were subjected to analysis with this CZE-MS system. Information was obtained about the degradation of the C-terminal semi-carbazide group. A major difference between CZE an d LC is that goserelin epimers are not separated in the CZE system, wh ereas they are in the RP-HPLC system. (C) 1997 Elsevier Science B.V.