Removal Of Procymidone Residues In Ginsenosides Extracts

Ginseng,one kind of Chinese herbals,has pharmacological functions of retarding aging,enhancing immunity,stimulating the circulation of blood and lowering blood pressure.The quality index of ginseng and ginseng products is its pesticide residue amount.For example,European Union requires that the content of pesticide residues such as procymidonein ginseng and ginseng products should not exceed 0.1 mg/kg.To explore the removal of pesticide residues in ginseng has important economic and practical significance.In this paper,three methods including organic solvent extraction,macroporous resin adsorption and macroporous resin adsorption-supercritical fluid extraction were used to remove procymidone from ginsenosides extracts and recover ginsenosides for meeting the quality standard of procymidone..For organic solvent extraction,the influences of various factors on the procymidone removal rate and ginsenosides recovery rate were investigated in this paper.The optimal conditions were obtained as follows: volume ratio of n-hexane to chloroform solution as the extractant is 2:3,volume ratio of the extractant to ginsenosides solutionis 1:1,extraction time is 60 min and extraction temperature is 40 °C.Under the optimal condition,the content of procymidone in ginsenosides extracts decreased from 44.51 mg/kg to 2.47 mg/kg,the removal rate of procymidone was 94.45% and the recovery rate of ginsenosides was 82.83%.With macroporous resin adsorption method,the suitable resin was screened out and the results showed that H-103 resin showed good performance in the removal of procymidone and recovery of ginsenosides.The removal rate of procymidone was 99.72%,the procymidone content was 0.098 mg/kg and the recovery rate of ginsenosides was 85.30% when the concentration of loading solution is 0.025 g/mL,the flow rate of loading solution is 1 BV/h,1.5 BV water and 3 BV 50% ethanol acted as the eluent at a flow rate of 1 BV/h.After macroporous resin was regenerated and reused for eight times,the adsorption performance decreased dramatically,the removal rate of procymidone was less than 90% and the recovery rate of ginsenosides was only 78.64%.Inorder to further improve the technology,lower the procymidone content and increase the recovery of ginsenosides,the macroporous resin adsorption-supercritical CO2 extraction method was adopted.D-101-1 resin with 40 vol.% acetonen-hexane as the modifier at a flow rate of 1.5 mL/min,25 MPa,55°C,and 2 h were chosen to remove procymidone.The absolute ethanol as the modifier at a flow rate of 1 mL/min,20 MPa,60 °C and 1 h were carried out to extract ginsenosides.After this process,procymidone content was 8.9 ppb,the procymidone removal rate was 99.98% and ginsenosides recovery rate was 92.48%.After D-101-1 resin was directly reused for six times without additional regeneration,the procymidone content in ginseng extract was 68.9 ppb,the recovery rate of ginsenosides was 91.02%.Macroporous resin adsorption-supercritical fluid extraction technology has advantages in high removing rate of procymidone,high recovery rate of ginsenosides,short production period and high utilization rate of resin and direct reuse without additional regeneration.