Abstract
Captopril, a well‐known angiotensin converting enzyme (ACE) inhibitor, is widely used for treatment of arterial hypertension. Recent studies suggest that it may also act as a scavenger of free radicals because of its thiol group. Therefore, the present study describes a rapid, sensitive and relatively simple method for the detection of captopril in biological tissues with reverse‐phase HPLC. Captopril was first derivatized with ThioGlo™3 [3H‐Naphto[2,1‐b]pyran,9‐acetoxy‐2‐(4‐(2,5‐dihydro‐2,5‐dioxo‐1H‐pyrrol‐1‐yl)phenyl‐3‐oxo‐)]. It was then detected by fluorescence‐HPLC using an Astec C~18~ column as the stationary phase and a water:acetonitrile:acetic acid:phosphoric acid mixture (50:50; 1 mL/L acids) as the mobile phase (excitation wavelength, 365 nm; emission wavelength, 445 nm). The calibration curve for captopril was linear over a range of 10–2500 nM and the coefficient of variation acquired for the within‐ and between‐run precision for captopril was 0.5 and 3.8%, respectively. The detection limit of captopril with this method was found to be 200 fmol/20 µL injection volume. Its relative recovery from biological samples was determined to the range from 93.3 to 105.3%. Based on these results, we believe that our method is advantageous for captopril determination. Copyright © 2001 John Wiley & Sons, Ltd.
Abbreviations used:
ACE
angiotensin converting enzyme
PBPB
P‐bromophenylbromide
ROS
reactive oxygen species