Determination of Four Flavonoids in Cuscuta chinensis Lam. by HPLC with Ultrahigh Pressure-Assisted Cloud Point Extraction

摘要

In this paper, a novel two-step extraction technique combining ultrahigh pressure-assisted micellar extraction with cloud point extraction was presented for the extraction and pre-concentration of four flavonoids (hyperoside, quercitrin, quercetin and kaempferol) from the seeds of Cuscuta chinensis Lam. (Tu-si-zi) for the first time. Various experimental conditions were investigated to optimize the extraction process. Under the optimal conditions, i.e., 5 % (w/w) Triton X-100 solution, solid/liquid ratio of 1:30 (g/mL), with 100 MPa for only 1 min, the extraction efficiency of four flavonoids reached the highest value. The pre-concentration of four flavonoids by cloud point extraction were established as follows: the solution was incubated in a thermostatic water bath at 65 °C for 5 min and 15 % NaCl was added into the solution to facilitate the phase separation and increase the pre-concentration factor during the cloud point extraction process. The results indicated that the proposed method, combining two different and efficient techniques, offers satisfactory analytical features in terms of repeatability and reproducibility.