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Objective: To establish a method for simultaneous determination of wogonoside, 4'-hydroxywogonin, norwogonin, baicalein, wogonin and chrysin in health care products by high performance liquid chromatography （HPLC）. Methods: The samples were extracted with acetone, C18 solid phase extraction column was used for purification. The target compounds were determined by HPLC, quantified by matrix-matched standard curve method. Phenomenex Luna®C18（250 mm×4.6 mm, 5 μm）column was applied, mobile phase was acctonitrile-acetic acid, using gradient elution）at the flow rate of 1.0 mL/min. The temperature of column was 30 ℃ and the detection wavelength was set at 280 nm. Results: The results showed that these 6 target compounds had good separation and the corresponding concentration had a good linear relationship with the peak area. Correlation coefficients （R2） were all greater than 0.99, RSDs of precision and stability tests were within 3.08% and the average recoveries were 83%~100% （RSD＜4.63%）. The limits of detection were 0.02~0.07 mg/kg. The limits of quantification were 0.08~0.25 mg/kg. Conclusion: This method is suitable for simultaneous determination of flavonoids in health care products with good reproducibility, and less consumption of organic solvents.

Micro layer of GO was obtained by micro adjustment and control. LiFePO4/graphene composite cathode materials were synthesized using a spray drying followed by high temperature reduction modification method, to improve conductivity of LiFePO4 with excellent conductivity of graphene. The structure, morphology and electrochemical performance of the composite materials were characterized by XRD, FTIR, SEM, TEM and electrochemical measurement technologies. The three-dimensional conductive network was constructed by graphene composite in material particles, which can improve the charge transfer rate of the interface of electrolyte/electrode materials and the electrochemical performance of LiFePO4. The results show that the discharge specific capacity of LiFePO4 without graphene is only 155mAh/g, while the discharge specific capacity of LiFePO4/graphene is 164mAh/g at 0.1C.The discharge specific capacity of LiFePO4/graphene is 140,119mAh/g at 1,2C,respectively.

The CNTs/rGO/NG composite lithiumion battery anode material was synthesized by thermal reducing, using graphene oxide (GO) and carbon nanotubes (CNTs) as precursors for a 5 ∶ 3 proportion. The morphology, structure, and electrochemical performance of the composite were characterized by scanning electron microscopy(SEM), X-ray diffractometry(XRD), Fourier transform infrared spectra (FTIR) and electrochemical measurements. The results show that reduced graphene oxide and carbon nanotubes form a perfect three-dimensional network structure on the surface of natural graphite. CNTs/rGO/NG composite has good rate performance and cycle life,compared with pure natural graphite.The initial discharge capacity of designed anode is 479mAh/g at 0.1C, the reversible capacity up to 473mAh/g after 100 cycles,the capacity is still 439.5mAh/g, the capacity retention rate is 92%,and the capacity is 457, 433, 394mAh/g at 0.5, 1, 5C, respectively.