Application of integrative cloud point extraction and concentration for the analysis of polyphenols and alkaloids in mulberry leaves

A simple and efficient method based on cloud point extraction and concentration combined with high performance liquid chromatography was developed for the simultaneous separation and determination of five target compounds (deoxynojirimycin, chlorogenic acid, rutin, isoquercitrin and astragalin) in mulberry leaves samples. Firstly, to obtain a high extraction rate, the ultrasound assisted extraction was developed on acid modified Triton X-114 system. Under the optimal conditions, the total maximum extraction yields of five target compounds reached 20.80 mg/g, which was superior to conventional solvent extraction. After the cloud point extraction and concentration, the HPLC analysis parameters of calibration curve, intra-day and inter-day precision, limits of detection for the five target compounds were determined systematically. The proposed method was successfully used to extract, concentrate, separate and determine the polyphenols and alkaloids in mulberry leaves. (C) 2019 Elsevier B.V. All rights reserved.