1.Experimental studies on microwave-assisted extraction of baicalin from root of Scutellariae baicalensis
Zhenku GUO ; Qinhan JIN ; Guoqiang FAN ; Yuping DUAN ; Chen QIN ;
Chinese Traditional and Herbal Drugs 1994;0(11):-
Object To study the microwave assisted procedure for the extraction of baicalin from root of Scutellariae baicalensis Georgi Methods An MSP 100D domestically made microwave sample preparation system with a maximum power of 850 watts was used. The effects of solvents, pressure/temperature of solvents and microwave radiation time on the yield of baicalin were studied by orthogonal experimental design. Results The optimal experimental conditions were extraction at 70% of microwave power with 30 times of 35% ethanol at a constant heating pressure/temperature of 0.15 MPa for 30 s. Conclusion The microwave assisted extraction not only takes a shorter time with better parallel results, but also gave an increased yield of about 10% as compared with ultrasonic extraction.
2.Two New Ways to Improve the Sensitivity of Spectrophotometry
Huanwenv CHEN ; Yanbo CAO ; Songbai HAN ; Hanqi ZHANG ; Aimin YU ; Qinhan JIN
Chinese Journal of Analytical Chemistry 2001;29(4):478-483
The development of liquid core waveguide in recent years was reviewed and evaluated concisely. It was shown that the combination of liquid core waveguide and the ΔI measurement was an ideal strategy to improve the sensitivity of spectrophotometry