Volume 27, Number 1, January/February 1999Importance de la lipophilie en modélisation moléculaire
|Page(s)||53 - 56|
Potentiometric enantioselective membrane electrode for s-enalapril assayH.Y. Aboul-Enein1, R. I. Stefan2 and J.F. van Staden2
1 Bioanalytical and Drug Development Laboratory, Biological and Medical Research Department (MBC-03), King Faisal Specialist Hospital and Research Centre, P.O. Box 3354, Riyadh 11211, Saudi Arabia
2 Department of Chemistry, University of Pretoria, Pretoria 0002, South Africa
A novel potentiometric, enantioselective membrane electrode based on graphite paste (graphite powder and paraffin oil), impregnated with 10-3 mol/L 2-hydroxy-3-trimethylammoniopropyl--cyclodextrin (as chloride salt) solution, has been constructed. The potentiometric, enantioselective membrane electrode can be used for the reliable assay of S-enalapril as raw material and from its pharmaceutical formulations in the concentration range of mol/L with a detection limit of mol/L and with an average recovery of 99.96% (RSD = 0.098%), using a chronopotentiometric (zero current) technique. The enantioselectivity was determined versus D-proline and it was shown only L-proline is the main interfering compound. The surface of the electrode can be regenerated by simply polishing to obtain a fresh surface which is ready to be used in a new assay.
Key words: Potentiometry / enantioselective membrane electrode / enantioselective analysis / 2-hydroxy-3-trimethylammoniopropyl--cyclodextrin / S-enalapril.
© EDP Sciences, Wiley-VCH 1999