Objective:To establish a method by combining microwave-assisted extraction(MAE),solid phase extraction(SPE)and high performance liquid chromatography(HPLC)for determination of the mefenacet residues in rice.Methods:Acetone and acetontrile(37)were used as extraction solvent.Microwave-assisted extraction was used to extract mefenacet residues in the rice.The extracts were then cleaned up with a Florisil cartridge and then subjected to Hypersil C18 column(5 ?m,4.6 mm?200 mm),with acetonitrilewater(5050,V/V)solution as mobile phase and with a flow rate of 1.0 ml/min;the ultraviolet detection wavelength was at 217 nm.Results:Good linear correlation for mefenacet was found within a concentration range of 0.198-9.900 ?g/ml.The detection limit was 0.039 6 ?g/mL for mefenacet(S/N=2).The average recovery rate of rice hull and brown rice were 90.8%(RSD 1.8%)and 85.6%(RSD 2.5%),respectively.Conclusion:The present method is simple and rapid;it can be used for the determination of mefenacet residues in rice.

Objective:To search for a rapid and efficient method for the isolation of 3 kinds of isoflavone glucosides from the ethanol extract of Semen Sojae Praeparatum.Methods: The crude isoflavones were extracted by 75% aqueous ethanol after removing the oil by Soxhlet extraction.Then 1300 macroporous resin,water and different concentrations of aqueous ethanol(10%,20%,30%,40%,50%,70%,and 95%) were used to separate and elute the crude isoflavones.The fraction eluted by 40% aqueous ethanol was subjected to preparative HPLC analysis.The chromatographic conditions: A YWG C18(10.0 mm?200 mm,i.d.10 ?m) column was used;the mobile phase consisted of acetonitrile-water-acetic acid at volume ratio of 25751(V/V/V) and a flow rate of 3.0 ml/min;the injection volume was 750 ?l;and the detection wave length was set at 260 nm.Results: Daidzin,glycitin and genistin were rapidly separated with the purities over 99% as determined by external standard HPLC.Conclusion: This technique is simple and suitable for the isolation of daidzin,glycitin and genistin from Semen Sojae Praeparatum.

Objective:To optimize the preparation process of Qinggan Liangxue Granules.Methods:The L 9 (3 4) orthogonal experimental design was used to investigate the effects of water addition, extraction time and extraction times on the extraction process of Qinggan Liangxue Granules by taking the transfer rate of astilbin and paeoniflorin as the indexes, so as to screen the optimal extraction process. The evaluation indexes of granule molding rate, water content, solubility and fluidity were used to compare the effect of finished products under different ratios of excipients and granulation conditions. Results:The optimal extraction process was to add 10 times the amount of water reflux extraction twice, each time 1.5 h; using wet granulation, the ratio of dry paste powder to base material was 4:1 ( m/ m), and the wetting agent was 95% ethanol. Conclusion:The preparation process of Qinggan Liangxue Granules is stable and feasible, which lays a foundation for further research and development and quality control.