Corresponding Author

Yousif Taha Maaroof

Authors ORCID


Document Type

Research Article


ABSTRACT A simple, new, inexpensive and sensitive batch and flow injection spectrophotometric methods for determination of captopril in pharmaceutical products. The procedure was based on oxidationreduction reaction between of captopril with a known excess of bromine solution in acidic medium. Bromine solution in acid medium decolorize the Rhodamine B dye. A known excess of bromine in acidic medium treated with captopril followed by spectrophotometric determination of unreacted bromine, unreacted bromineby reacting with a fixed amount of Rodamine B dye at 555 nm. . Beer’s law was obeyed in the concentration ranges 0.3-2.3 μg mL-1 with detection limits 0.018 μg mL-1. The molar absorptivity and correlation coefficients (r) were 1.4x105 l/mol.cm, 0.9992 for batch method. The calibration graph constructed for FI method, obeyed Beer’s law in the concentration range (1-6 μg mL-1) with a molar absorptivity 2.1x104l/mol.cm, limit of detection 0.3 μg mL-1, correlation coefficient (r) 0.9987, , and sampling frequency 90 determinations per hour.


Captopril, Spectrophotometric, Flow injection, Bromine, Rhodamine B.

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