A six-channel fiber optic in-situ detection technique for simultaneous monitoring of desorption kinetics of quercetin from HPD300 resin

Desorption, is a critical and equally important phase of the entire adsorption process. The study of quercetin desorption kinetics is of great significance in guiding the adsorptive separation of bioactive compounds. Conventional methods for plotting desorption kinetic curves require manual sampling at different time points and offline tests. These methods are time-consuming, labor-intensive, yield limited data, and introduce significant error due to manual handling and variation in solution volume. Furthermore, conducting multi-throughput desorption operations simultaneously is challenging. Herein, a six-channel fiber-optic sensing in-situ detection technique was developed for the simultaneous, real-time monitoring of quercetin desorption process in multi-throughput, addressing these inherent issues. The established quercetin standard curves using the six-channel fiber-optic sensing system all demonstrated excellent linearity (R 2 ≥ 0.9998), exploiting the ability of this technique to obtain six desorption curves in a single cycle. The macroporous adsorption resin (MAR), specifically HPD300, was selected as the optimal adsorbent for the adsorptive separation of quercetin. Additionally, this technique was used to obtain the optimal desorption conditions: using 80% ethanol as the desorption solvent, an initial adsorption concentration of 25 mg L -1 , and a temperature of 298 K. Kinetic studies of desorption revealed that the pseudo-second-order (PSO) model was more suitable for describing the desorption of quercetin from HPD300. This technique can offer significant application potential in the adsorptive separation of bioactive compounds and greatly improve operational efficiency.