Simultaneous detection of S and R captopril using sequential injection analysis.

Area of Science:

• Analytical Chemistry
• Electrochemistry
• Biosensors

Background:

• Captopril exists as S- and R-enantiomers, with distinct pharmacological activities.
• Accurate and simultaneous determination of these enantiomers is crucial for quality control in synthesis.
• Existing methods may lack the efficiency or specificity for real-time monitoring.

Purpose of the Study:

• To develop a novel sequential injection analysis (SIA) system for simultaneous determination of S- and R-captopril.
• To utilize enantioselective potentiometric and amperometric sensors for selective detection.
• To validate the system for on-line monitoring in synthesis processes.

Main Methods:

• A sequential injection analysis (SIA) system was designed.
• An enantioselective membrane electrode using maltodextrin was employed for S-captopril detection.
• An amperometric biosensor was utilized for R-captopril detection.
• Simultaneous detection was achieved by integrating both sensor types within the SIA system.

Main Results:

• The SIA system achieved simultaneous detection of S- and R-captopril enantiomers.
• Linear concentration ranges were established: 1-1000 µmol/L for S-captopril and 100-1000 nmol/L for R-captopril.
• The system demonstrated high reliability with a relative standard deviation (RSD) better than 0.009% (n=10).
• A sample throughput of 38 samples per hour was achieved.

Conclusions:

• The proposed SIA system provides a reliable and efficient method for on-line simultaneous determination of captopril enantiomers.
• This approach is suitable for monitoring the synthesis process of captopril.
• The combination of potentiometric and amperometric sensing within SIA offers a powerful analytical tool.