Determination of Stachydrine Hydrochloride in Different Parts of Herba Leonuri by HPLC
Objective To control the quality of Herba Leonuri by studying the content of stachydrine hydrochloride in different parts of it. Method A HPLC method was developed for the content detetmination of stachydrine hydrochloride in flower, stem, leafage from Herba Leonuri. Spherisorb SCX colum was used with mobile phase of 20 mmol/L sodium dihydrogen phosphate (containing 0.04% triethylamine and 0.15% phosphoric acid). The colum temperature was 25 ℃, the detective wavelength was 192 nm. Results Stachydrine hydrochloride content was the highest in leafage and the lowest in stem. Conclusion To ensure the quality of Herba Leonuri, it is significant to choose medical material with more leafage.
The paper deals with the example of application of the two continuum rheological model of materials with microdefects, nanodefects and solute hydrogen for calculation of stress and strain in cylindrical specimen under periodic loading. The model suggested allows one to relate the mechanical characteristics with the hydrogen concentration.The stability analysis of the system metal-hydrogen is carried out. The influence of parameters of the mechanical loading, hydrogen concentration and parameters of sorption and desorption of hydrogen from the surface of the internal defects (traps) of various nature on the system stability is performed.It is shown that influence of hydrogen can be considered as parametric instability of a continuous medium under mechanical deformation.This can be important during forming or plastic deformation of materials and nanomaterials containing hydrogen.