The Extraction, Separation, Purification Of Aloin From Aloe And Its Application In Cosmetics

The extraction,separation,purification,and testing methods of aloin from Aloe Vera were studied in this paper,and its application in cosmetics was also examined .The ultrasonic extraction method was selected to extract aloin from leaves of Aloe Vera based on the results of three different extraction methods: the immerse extraction method,the continuous circumfluence method and the ultrasonic method. The optimum extraction condition using ultrasonic method is: ethanol concentration 60%,ultrasound power 270W,the ratio of raw material to extraction solvent 1:30,extraction time 40min. Meanwhile,the concentration of extracted aloin was also measured using several methods. High Performance Liquid Chromatography (HPLC) method gives the most accurate result while the results from Ultraviolet Spectroscopic method and the Pharmacopoeia method is higher than the actual concentration due to the interference of other anthraquinones. Although the Thin Layer Chromatograph (TLC) method can achieve a result close to HPLC,the procedure is too complex for aloin concentration mornitoring in large scale industrial production.Macro-porous Adsorption Resin and silica gel pillar were used to improve the purity of aloin. Experimental results showed that both NKA-â…¡and CAD45 adsorption resins had a higher capacity of adsorbing,but only NKA-â…¡had a notable ratio of sample recovery during the desorption process. Therefore,the macro-porous adsorption resin (NKA-â…¡) column were first used to purify aloin using the following conditions: 1.5BV (bed volume) sample extract was injected through the column with a flow rate of 2.0mL/min,then the column was washed by 1.0BV distilled water,2.0BV 60% ethanol,and 2.5BV 70% ethanol. The content of aloin in the crude aloin product increased from 0.13% to 4.9% after collecting,concentrating,and freezing drying. After using silica gel column for further purification,the content of aloin increased to 69.5%,and the LC-MS results of the final product confirmed the effectiveness of the procedure. Finally,the extracted and purified aloin was also added to the sunscreen cosmetics product and its property of sunscreen and moisture- absorption were further studied.