Infrared-assisted non-ionic surfactantextraction as a green analytical preparatory technique for the rapid extraction and pre-concentration of picroside I and picroside II from Picrorhiza scrophulariiflora Pennell

Abstract

The extraction of picroside I and picroside II from Picrorhiza scrophulariiflora Pennell using non-ionic surfactants with the assistance of infrared was investigated and the conditions for maximum yield were determined. Under optimum conditions, i.e. 10% Genapol X-080 (v/v), liquid : solid ratio of 150 : 1 (mL g⁻¹), infrared power 200 W and infrared-assisted extraction for 4 min, the extraction yield reached the highest value. For the preconcentration of picroside I and picroside II by cloud-point extraction, the solution was incubated in a thermostatic water bath at 100 °C for 10 min, and 15% NaCl (w/v) was added to the solution to facilitate the phase separation. When compared with various polar and nonpolar solvents (pure water, ethanol, acetone, acetic ether and hexane), the extraction efficiency of 10% Genapol X-080 reached a statistically higher value (p < 0.05). By using an infrared-assisted non-ionic surfactant extraction method, the determined amounts of the picrosides in Picrorhiza scrophulariiflora Pennell were statistically higher than those extracted with conventional ultrasound-assisted extraction and heat-reflux extraction (p < 0.05). The results show that infrared-assisted non-ionic surfactant extraction is a good, efficient and green analytical preparatory technique for the rapid extraction and pre-concentration of pharmacologically active ingredients from Picrorhiza scrophulariiflora Pennell without disturbing the subsequent chromatographic analysis.