HPLC Determination of Chlorpropamide in Human Serum by Fluorogenic Derivatization Based on the Suzuki Coupling Reaction with Phenylboronic Acid

A fluorogenic derivatization method for the determination of chlorpropamide in human serum was developed by means of high-performance liquid chromatography (HPLC) with fluorescence detection. The Suzuki coupling reaction with a non-fluorescent reagent, phenylboronic acid (PBA), was employed to convert chlorpropamide into highly fluorescent biphenyl derivative. Chlorpropamide was extracted from human serum by liquid–liquid extraction with toluene after addition of hydrochloric acid, and subsequently reacted with PBA. Because the fluorogenic derivatization was highly selective for aryl halide, the proposed method allowed sensitive and selective detection of chlorpropamide with a detection limit (at a signal to noise ratio of 3) of 0.5 ng mL⁻¹. The sensitivity of our method was from 4 to 100 times better than HPLC–UV, gas chromatography, and LC-mass spectrometry.