Simultaneous determination of aconitum alkaloids in rat body fluids by high-performance liquid chromatography

A sensitive, reliable and accurate high-performance liquid chromatography (HPLC) method coupled with photodiode array detector (DAD) were developed for the simultaneous quantitative determination of aconitine, mesaconitine and hypaconitine in rat plasma and urine by optimizing the extraction, separation and analytical conditions. The analyses were chromatographed on a ZORBAX Eclipse XDB-C18 column (150 mm ~ 4.6 mm i.d.; 5 ƒÊm particle size) with gradient elution using solvents ofacetonitrile and ammonium acetate buffer (pH 10.0). The detection wavelength was 240 nm. Intra-assay and inter-assay precision of the analyses were less than 10% and the average recovery rates obtainedwere in the range of 85.63 - 90.94% for all analysis of the three aconitum alkaloids with relative standard deviations (RSD) below 14%. Positive linear relationships were observed in correlation coefficients that exceeded 0.95. The limits of detection (signal-to-noise ratio of 3) were 2.64, 1.58 and 2.75 ng for aconitine, mesaconitine and hypaconitine, respectively. The method can provide a scientific and technical platform to determine the concentration of aconitum alkaloids in plasma during a pilot pharmacokinetic study in rats

Synthesis and characterization of polypyrrole doped with anionic spherical polyelectrolyte brushes

The procedures for the synthesis of polypyrrole (PPy) doped with anionic spherical polyelectrolyte brushes (ASPB) (PPy/ASPB nanocomposite) by means of in situ chemical oxidative polymerization were presented. Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopic analysis suggested the bonding structure of PPy/ASPB nanocomposite. Scanning electron microscopy (SEM) was used to confirm the morphologies of samples. The crystallographic structure, chemical nature and thermal stability of conducting polymers were analyzed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Thermo-gravimetric analysis (TGA) respectively. Investigation of the electrical conductivity at room temperature showed that the electrical conductivity of PPy/ASPB nanocomposite was 20 S/cm, which was higher than that of PPy (3.6 S/cm)