Optimization of High-Performance Liquid Chromatography (HPLC) Conditions for Isoflavones Using Deep Eutectic Solvents (DESs) as Mobile Phase Additives by the HCI Program
Dong Min Choi, Sile He, Kyung Ho Row
Abstract
Isoflavone exhibits estrogen-like structure and activity and has various physiological and pharmacological functions, such as anticancer, antioxidant, and anti-inflammatory. In this study, several deep eutectic solvents (DESs) were synthesized and used as mobile phase additives to optimize the analytical conditions of five isoflavones. The DES composed of choline chloride:citric acid (molar ratio 1:1) was the most effective mobile phase additive with reduced peak tailing, improved peak shape, and increased number of theoretical plates. The effectiveness of the DES highlights its potential as a mobile phase additive. The optimal high-performance liquid chromatography (HPLC) conditions for the isoflavones were determined by the Intelligent HPLC simulator. The optimal conditions for gradient elution were water (A): acetonitrile (B) for 0 min, 25% B; 15 min, 25% B; 17 min, 35% B; and 50 min, 35% B. This approach provided excellent linearity (0.5 to 500 μg/mL, R2 ≥ 0.9991), limits of detection (0.024 to 0.109 μg/mL), limits of quantification (0.079 to 0.363 μg/mL), and precision (1.74 to 4.80%).