RESUMO
Objective To study the phase transformations and chemical composition changes of Pyritum Preparata (PP) influenced by different processing. Methods To analyse the changes of microstructure, morphology, mineral phase, and chemical compositions in different PP by ore microscope, electron probe microanalyzer technique. Results Greater changes have taken place in chemical compositions of PP after calcination: pyrite (FeS_2) changed into pyrrhotite (Fe_(1-x)S), even changed into magnetite (Fe_3O_4); and chalcopyrite generated mutation to be low-copper chalcopyrite, the contents of Cu reduced, the rate of Cu/Fe changed. At the same time, in the pyrrhotite around the mutative chalcopyrite, the contents of Cu increased. That is to say, the Cu got into pyrrhotite and generated solid-solution with high dispersion, and then ore became loose and porous. In the hard-burned spot of calcined quenched samples by vinegar, the contents of Pb and S are far lower than non-burned spot, the minimum estimate of Pb is less than 1/10 of crude ore. Conclusion There is a co-relativity between phase transformations and dissolution of chemical compositions before and after calcining PP.
RESUMO
Several factors influencing the extraction of tetrandrine and demethyltetrandrine from Chinese medicinal herbs, Stephania tetrandra S. Moore were studied by means of Ortogonal method. The optimum Condition was eight hours steeping, in 33.3% ammonia in absolute alcohol for four hours under ultrasonic agitation. Tctrandrine aud demethyltetrandrino were detected by HPLC. The contents were 0.678% and 0.616%, the detection limits were 3.87?10-3and 0.48?10-3 mmol/L respectively.