RESUMEN
The chlorogenic acid, rosmarinic acid, and caffeic acid contents in 100 selected plants were determined using reversed phase high performance liquid chromatography equipped with diode array detector. The optimum condition was 0.2% phosphoric acid in water (solvent A) and methanol (solvent B) as the mobile phase, which was set at 45% B for 20 minutes at a flow rate of 1.2 mL/min. The column temperature was maintained at 30 ºC and the detection wavelength was 325 nm. Among 100 selected plants, 39.64% contained all 3 compounds, 40.54% contained 2 compounds, 14.41% contained only 1 compound, and 5.41% could not detect any of the 3 compounds. The highest contents of chlorogenic acid, rosmarinic acid, and caffeic acid were found in Lonicera japonica flowering buds, Melissa officinalis leaves, and Coffea canephora seeds at the concentration of 9.900 ± 0.004, 19.908 ± 0.171, and 1.233 ± 0.003 g/100 g of dried plant, respectively.
RESUMEN
To establish a rapid determination method of six flavonoids:catechin,rutin,myricetin,quercetin,kaempferol and isorhamnetin,from seabuckthorn leaves by RP-HPLC-DAD.The seabuckthorn leaves were first degreased by petroleum ether,extracted by ethanol,and determined by RP-HPLC-DAD.The six flavonoids were separated and eluted by a Shimadzu C18(150 mm ×2.1 mm,5 μm) column with methanol-water (0.1％ phos phoric acid) (60∶ 40) at a flow rate of 1.0 mL/min.The detection wavelength were as follow:catechin 208 nm,rutin 257 nm,myricetin 373 nm,quercetin 371 nm,kaempferol 367 nm,and isorhamnetin 371 nm,respectively.The injection volume was 20 μL.The contents of the six flavonoids were in the range of 0.47 to 30.00 μ,g/mL with good linearity.The validation of the method,including precision,stability and recovery rate,was acceptable.The established method can be used for fast determination of the content of six flavonoids in seabuckthorn leaves.
RESUMEN
OBJECTIVE: To establish a new method for determination of the main active ingredient and its isomer in commercially available calcitriol capsules by reverse phase-high performance liquid chromatography-diode array detector (RP-HPLC-DAD). METHODS: The chromatographic separation was performed on a Symmetry C18 column (4.6 mm × 250 mm, 5 μm) with gradient elution of water-acetonitrile-methanol. The mass spectrometer was equipped with diode array detector. Using Chem Station chromatography workstation, the main ingredient and its isomer in commercially available calcitriol capsules were analyzed. RESULTS The linear ranges of calcitriol and its isomer were 0.171 4 - 1.36 and 0.161 3 - 1.28 μg·mL-1, the detection limits were 39.75 and 40.90 ng·mL-1 and the limits of quantification were 141.6 and 136.4 ng·mL-1, respectively. The specificity of the method was good, the RSD values of the precision and stability tests were less than 1.2%, and the recoveries were greater than 98%. The average contents of calcitriol capsules from three manufacturers were 72.71%, 80.35%, and 78.18%, respectively. CONCLUSION: The method is simple, rapid, accurate, and easy to be popularized, which is suitable for the determination of calcitriol and trans-calcitriol in calcitriol capsules.