Eco-friendly separation of catechins using cyclodextrins as mobile phase additives in RP-HPLC

New mobile phases for RP-HPLC were developed for the separation of catechin compounds in tea. Cyclodextrin mobile phase additives decreased the use of toxic and inflammable organic solvents without compromising resolution or separation efficiency.

To develop a simple greener method for analyzing five tea catechins in RP-HPLC, the mobile phase condition was optimized and the lowest organic modifier proportion with content resolutions and retention factors were obtained.

Eco-friendly cyclodextrins were used as mobile phase additives to decrease the proportion of organic modifier and improve resolutions and retention factors.

The effects of several physico-chemical parameters on the retention factors were investigate d and the optimum conditions were obtained on a conventional C₁₈ column, where the mobile phase consisted of acetonitrile/water (12/88, v/v) with 1.5 mmol/L β-cyclodextrin at a flow rate of 1.0 mL/min.

Cyclodextrins can separate analytes through host-guest complexation, where a transient diastereomeric complex is formed between the cyclodextrin and the analyte. β-Cyclodextrin is the most accessible, the least expensive and generally the most useful cyclodextrin.

This work developed a simple eco-friendly method with the lowest concentration of organic solvents. Under the optimal condition, five catechins could be baseline separated within 17 minutes in the isocratic mode. This research exhibited the potential for the separation and determination of other active compounds from natural plants by a greener method.