| The functional component of rosemary fat soluble antioxidant is carnosic acid,which has been gradually applied in food additives and other fields,and the market demand is increasing.At present,the content of rat tail oxalic acid in mainstream market is less than or equal to 30%,and the HPLC method of analyzing rat tail oxalic acid takes a long time,which can not meet the requirements of quality control in the middle link of production.Therefore,the research on separation,purification and rapid detection of carnosic acid has attracted close attention.Firstly,the middle sample of carnosic acid was separated from the crude oil of rosemary fat soluble antioxidant by liquid-liquid extraction method,then the high purity carnosic acid was prepared by semi preparative high performance liquid chromatography,or the high purity carnosic acid was prepared by membrane separation method directly,and the best process parameters were explored respectively;the method of rapid detection of the carnosic acid content in rosemary was established.The experimental results are summarized as follows:（1）The process of extracting and separating the middle sample of carnosic acid is as follows:firstly,20 times of the volume of dichloromethane is used to dissolve the crude oil of rosemary fat soluble antioxidant,then according to the volume ratio of 1:3,the concentration of 12 mg/m L is used sodium bicarbonate solution was shaken and extracted three times,then kept for 8 minutes to separate phases,adjusted the p H value of the extraction solution to 2-3,that is to say,the purity of carnosic acid is 60.77%,and carnosol is 6.34%.The total extraction rate is 92.1%.（2）The optimal conditions for purification of carnosic acid by membrane separation method are as follows:take the rosmarinus oil soluble antioxidant 70%ethanol solution with concentration of 50mg/m L as the separation stock solution,the ultrafiltration membrane with 30KDa MWCO was carried out this separation twice at0.5MPa;then the filtrate was ultrafiltrated with the 5KDa MWCO membrane at 0.35Mpa,and the retention fluid was collected,and finally it was condensed by vacuum and freeze-drying,the product contained carnosic acid and carnosol was obtained.In this product carnosic acid is equal 83.29%,carnosol 0.17%,and the total recovery of carnosic acid is 92.2%.（3）The optimized conditions for purification of carnosic acid by semi preparation HPLC are as follows:the sample solvent is anhydrous ethanol,the mobile phase is acetonitrile/0.1wt%acetic acid for gradient elution,the raw material of rat tail oxalic acid is prepared with anhydrous ethanol into a solution with a concentration of 100mg/ml,and the flow rate is 20ml/min.The purity of carnosic acid was 99.13%,carnosol was 0.12%,and the recovery of salvianolic acid was 65.57%.（4）A rapid spectrophotometric method for the determination of carnosic acid in rosemary was established.The results showed that the RSD of the three indexes of the precision,repeatability and recovery of the spectrophotometric method is 0.12%,0.41%and 3.10%,respectively.In the range of 10%～30%,the real content of oxalic acid YZ=the apparent content(9.2×10-3x-3×10-15)-（20+0.33n）n=1-24;in the range of 30%～66%,the real content YZ=the apparent content(8.4×10-3x+0.16)-12%. |
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