Spectrophotometric method for the determination of ketoconazole based on amplification reactions

This paper describes a sensitive spectrophotometric method developed for determination of Ketoconazole (KC) in tablets based on amplification reactions. Ketoconazole was oxidized with periodate, resulting in formation of KC2+ and iodate ions. After masking the excess periodate with molybdate, the iodate was treated with iodide to release iodine. The liberated iodine was transformed to ICl2−ICl2− species and extracted as ion-pair with rhodamine 6G into toluene for spectrophotometric measurement at 535 nm. A linear calibration graph was obtained between 0.2136 μg/mL and 1.7088 μg/mL of Ketoconazole with a molar absorptivity of 5×105 mol·L−1 cm−1. The procedure was successfully applied for the determination of ketoconazole in tablet formulation.