High Performance Liquid Chromatography (HPLC) experiments have been performed on nine steviol glycosides namely rebaudioside A, steviolbioside, stevioside, rubusoside, rebaudioside B, rebaudioside C, rebaudioside D, r...High Performance Liquid Chromatography (HPLC) experiments have been performed on nine steviol glycosides namely rebaudioside A, steviolbioside, stevioside, rubusoside, rebaudioside B, rebaudioside C, rebaudioside D, rebaudioside F, and dulcoside A isolated from the leaves of Stevia rebaudiana using Reversed-Phase (RP) column. Using RP-HPLC method, the individual retention times for nine naturally occurring ent-kaurane diterpene glycosides of S. rebaudiana reported in JECFA have been determined at four different temperatures: 20℃, 40℃, 60℃, and 79℃. Also, calculated the relative retention times of the eight steviol glycosides steviolbioside, stevioside, rubusoside, rebaudioside B, rebaudioside C, rebaudioside D, rebaudioside F, and dulcoside A against the major steviol glycoside rebaudioside A. HPLC results suggested that temperatures 40℃ and 60℃ would be ideal conditions for better separation of steviol glycosides.展开更多
A new reversed-phase high performance liquid chromatography method was developed to quantitate the activity of xanthine oxidase involved in milk fat globule membrane with xanthine as the substrate and the separation o...A new reversed-phase high performance liquid chromatography method was developed to quantitate the activity of xanthine oxidase involved in milk fat globule membrane with xanthine as the substrate and the separation of product (uric acid). The increment of uric acid in the reaction system was used to calculate the total activity of XO. The optimized assay conditions, linearity of detection, recovery of uric acid and chromatogram were developed in text, indicating this method is simple, rapid and efficient. It is an alternative potential method for the determination of the activity of XO in milk.展开更多
[Objectives] To establish the high performance liquid chromatography( HPLC) determination method for oxysophocarpine and optimize the extraction and purification technology of oxysophocarpine from Sophora alopecuroide...[Objectives] To establish the high performance liquid chromatography( HPLC) determination method for oxysophocarpine and optimize the extraction and purification technology of oxysophocarpine from Sophora alopecuroides by inverse three-phase membrane cycle.[Methods]Based on the single-factor experiment,the effects of aqueous phase and organic phase volume ratio,the concentration of sodium hydroxide,concentration of hydrochloric acid and extraction cycle time on extraction process of oxysophocarpine were investigated using orthogonal design method,to determine the optimal extraction process. [Results]The oxysophocarpine was determined by Shim-pack VP-ODS chromatographic column( 4. 6 mm × 250 mm,5 μm),mobile phase was methanol-0. 2% phosphoric acid aqueous solution( 7∶ 93),gradient elution,flow rate was 1 m L/min,the sample size was 5 μm,column temperature was 30℃,detection wavelength was 221 nm. Aqueous phase and organic phase volume ratio was 1∶ 1,hydrochloric acid concentration was 0. 3 mol/L,sodium hydroxide concentration was 0. 75 mol/L,water pump flow rate was 6 m L/min,60 min cycle time. The extraction rate of oxysophocarpine 98. 21 % within 60 min under the best experimental conditions. Oxysophocarpine has good linearity relationship within the range of 0. 01-0. 7 mg/m L( r^2= 0. 9978,n = 6),the respective average recovery rate was 97. 47%( RSD = 1. 95%). [Conclusions] This extraction process is simple in operation,the organic solvent has low consumption,and can be used for extraction of alkaloid.展开更多
文摘High Performance Liquid Chromatography (HPLC) experiments have been performed on nine steviol glycosides namely rebaudioside A, steviolbioside, stevioside, rubusoside, rebaudioside B, rebaudioside C, rebaudioside D, rebaudioside F, and dulcoside A isolated from the leaves of Stevia rebaudiana using Reversed-Phase (RP) column. Using RP-HPLC method, the individual retention times for nine naturally occurring ent-kaurane diterpene glycosides of S. rebaudiana reported in JECFA have been determined at four different temperatures: 20℃, 40℃, 60℃, and 79℃. Also, calculated the relative retention times of the eight steviol glycosides steviolbioside, stevioside, rubusoside, rebaudioside B, rebaudioside C, rebaudioside D, rebaudioside F, and dulcoside A against the major steviol glycoside rebaudioside A. HPLC results suggested that temperatures 40℃ and 60℃ would be ideal conditions for better separation of steviol glycosides.
文摘A new reversed-phase high performance liquid chromatography method was developed to quantitate the activity of xanthine oxidase involved in milk fat globule membrane with xanthine as the substrate and the separation of product (uric acid). The increment of uric acid in the reaction system was used to calculate the total activity of XO. The optimized assay conditions, linearity of detection, recovery of uric acid and chromatogram were developed in text, indicating this method is simple, rapid and efficient. It is an alternative potential method for the determination of the activity of XO in milk.
基金Supported by Project of National Natural Science Foundation(21162030)
文摘[Objectives] To establish the high performance liquid chromatography( HPLC) determination method for oxysophocarpine and optimize the extraction and purification technology of oxysophocarpine from Sophora alopecuroides by inverse three-phase membrane cycle.[Methods]Based on the single-factor experiment,the effects of aqueous phase and organic phase volume ratio,the concentration of sodium hydroxide,concentration of hydrochloric acid and extraction cycle time on extraction process of oxysophocarpine were investigated using orthogonal design method,to determine the optimal extraction process. [Results]The oxysophocarpine was determined by Shim-pack VP-ODS chromatographic column( 4. 6 mm × 250 mm,5 μm),mobile phase was methanol-0. 2% phosphoric acid aqueous solution( 7∶ 93),gradient elution,flow rate was 1 m L/min,the sample size was 5 μm,column temperature was 30℃,detection wavelength was 221 nm. Aqueous phase and organic phase volume ratio was 1∶ 1,hydrochloric acid concentration was 0. 3 mol/L,sodium hydroxide concentration was 0. 75 mol/L,water pump flow rate was 6 m L/min,60 min cycle time. The extraction rate of oxysophocarpine 98. 21 % within 60 min under the best experimental conditions. Oxysophocarpine has good linearity relationship within the range of 0. 01-0. 7 mg/m L( r^2= 0. 9978,n = 6),the respective average recovery rate was 97. 47%( RSD = 1. 95%). [Conclusions] This extraction process is simple in operation,the organic solvent has low consumption,and can be used for extraction of alkaloid.
