RESUMO
OBJECTIVE： To establish a method for simultaneous determination of gallic acid， cinnamic acid and catechin in 3 processed products of Rheum officinale. METHODS： RP-HPLC method was established. The determination was performed on Thermo ScientificTM Hypersil GOLD Dim column with mobile phase consisted of methanol-0.1％ phosphoric acid solution （gradient elution） at the flow rate of 1.0 mL/min. The detection wavelength was set at 278 nm， and the column temperature was 30 ℃. The sample size was 10 μL. RESULTS： The linear range of gallic acid， cinnamic acid and catechin were 0.126 2-1.262 0 μg（r＝0.999 9）， 0.036 2-0.362 0 μg（r＝0.999 9） and 0.177 9-1.779 4 μg（r＝0.999 8）， respectively. Quantitative limits were 25.4， 28.2， 62.5 ng， and detection limits were 6.2， 3.6， 11.8 ng， respectively. RSDs of precision， stability， repeatability and durability tests were all less than 3％. The recoveries ranged from 94.64％-102.71％（RSD＝2.74％， n＝9）， 95.35％-102.49％（RSD＝2.44％， n＝9）， 93.56％-103.66％（RSD＝3.27％， n＝9）. The determination results showed that the contents of gallic acid and cinnamic acid in prepared R. officinale were higher， and the order of both were prepared R. officinale＞steamed R. officinale＞raw R. officinale. The content of catechin in raw R. officinale was higher， and the order of it was raw R. officinale＞ steamed R. officinale＞prepared R. officinale. CONCLUSIONS： The method is sensitive， reliable and reproducible. It can be used to determine the contents of gallic acid， cinnamic acid and catechins in 3 processed products of R. officinale simultaneously.
RESUMO
Objective To establish an HPLC method for determination of related substances of dexmethylphenidate hydrochloride and their content .Methods The HPLC method was used on an Agilent ZORBAX SB-C18 column with a mo-bile phase of methanol-0.2%triethyl citrate in 25 mmol/L potassium dihydrogen phosphate ( pH was adjusted to 3.5 with phosphoric acid) (35∶65) at a flow rate of 1.0 ml/min.The detection wavelength was 209 nm and column temperature was 40℃.Results Under the selected chromatographic condition , dexmethylphenidate hydrochloride was completely separated from impurity.The limit of detection was 81.12 ng/ml.The calibration curve was linear in the range of 2-30 μg/ml ( r=0.9995).The average recovery of the method was 100.83%, and the stability of the working solution was acceptable in 12 h(RSD=0.10%).Conclusion This method is simple,specific,accurate and suitable for analyzing the related substances and their content in dexmethylphenidate hydrochloride .
RESUMO
Objective:To establish the quality control of Zhiqikang capsules. Methods:TLC was used to identify Gastrodia tuder halimasch, rhubarb and Astragalus mongholicus in the preparations. A spectrophotometry method with 3, 5-dinitrosalicylic acid (DNS) was used to measure the polysaccharide content in Zhiqikang capsules. A spectrophotometry method with Forint phenol method ( Low-ry) was used to measure the peptide content in the capsules. Results:The linear range of polysaccharide was obtained between 6. 412 and 32. 060μg·ml-1(r=0. 999 5), the average recovery was 95. 86% and RSD was 0. 86%. The linear range of peptide was ob-tained between 0.059 7 and 0.298 4 mg·ml-1(r=0.999 0), the average recovery was 100.3% and RSD was 1.88%(n=6). Conclusion:The assay method is simple and accurate in the quality control of the preparations.