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Simultaneous quantitative determination of active components in Tetrastigma hemsleyanum by RP-HPLC coupled with diode array detection

Zhu Y., Yin Q., Du P., Huang S., Yang Y.

Acta Chromatographica

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2018

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Vol. 30, no. 3

186--190

EN

An effective, reliable, and sensitive reversed-phase high-performance liquid chromatography (RP-HPLC) with diode array detector (DAD) method was investigated for simultaneous determination of polydatin, isoquercitrin, resveratrol, and nicotiflorin in Tetrastigma hemsleyanum. The chromatographic separation of the four compounds was carried out on a Welchrom ODS column (4.6 mm × 250 mm, 5 μm) by gradient elution with phosphoric acid (H3PO4) aqueous solution (0.4%)–methanol as the mobile phase, at the temperature of 30 °C and a flow rate of 1.0 mL/min. The detection wavelength was set at 270 nm. Under optimum conditions, the baseline separation of these four compounds can be performed within 30 min. The developed method was validated in terms of detection limit, quantification limit, linearity, precision, and recovery tests. Eventually, the established HPLC–DAD method was successfully applied to the simultaneous determination of polydatin, isoquercitrin, resveratrol, and nicotiflorin in the extract of herb T. hemsleyanum.

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Room-temperature ferromagnetism in Fe-doped Na0.5Bi0.5TiO3 crystals

Wang Y., Xu G., Yang L., Ren Z., Wei X., Weng W., Du P., Shen G., Shen G., Han G.

Materials Science Poland

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2009

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Vol. 27, No. 2

471--476

EN

Fe-doped Na0.5Bi0.5TiO3 crystals were synthesized and studied by X-ray diffraction, X-ray spectroscopy, scanning electron microscopy, high-resolution transmission electron microscopy, and magnetic property measurement system. Room-temperature ferromagnetism was observed in Fe-doped Na0.5Bi0.5TiO3 crystals. It was found that the magnetism of Na0.5Bi0.5TiO3crystals can be controlled by the Fe dopant concentration. The magnetism of the Fe-doped Na0.5Bi0.5TiO3 crystals develops from diamagnetism to ferromagnetism and paramagnetism on increasing the Fe doping concentration from 0 to 10 mol %. The results presented in this study may provide new insights to the problem of synthesizing more single-phase multiferroic materials which will hopefully lead to rich and fascinating fundamental physics.

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Enhancement of ferromagnetic properties in Ni-doped BiFeO3

Wang Y., Xu G., Yang L., Ren Z., Wei X., Weng W., Du P., Shen G., Han G

Materials Science Poland

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2009

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Vol. 27, No. 1

219--224

EN

Ni-doped BiFeO3 samples were successfully synthesized by a hydrothermal method. The as-prepared samples were characterized by X-ray diffraction (XRD), and energy dispersive X-ray spectroscopy (EDS). It was found that the magnetization can be controlled by the Ni doping concentration. The magnetization of Ni-doped BiFeO3 was greatly enhanced when the Ni doping concentration was 0.5%. Therefore, it would be interesting to fabricate thin films with similar composition and study their properties with the aim of identifying new device applications.