Applications Research Of Ultrasound/Microwave Assisted Extraction

Ultrasound/microwave assisted extraction(UMAE),which is a complementary technique involving the coupling of microwave assisted extraction and ultrasonicassisted extraction,makes full use of ultrasonic cavitation and high-energy effect of microwave.The ultrasonic vibrational energy and microwave energy through the waveguide are applied on the samples or materials at the same time.It has showed that UMAE is a rapid,environmental friendly and efficient technique.Ultrasound/microwave assisted extraction coupled to headspace solid-phase microextraction(UMAE-SPME)based on UMAE was developed.Based on the combination of the above methods and gas-chromatography mass spectrometry,I have analyzed the compounds of the essential oil of Schisandra chinensis,the fatty acids in kinds of beans and the volatile components of the tobaccos.The main contents of this paper were given as follows:1.A potential ultrasound/microwave assisted steam distilation(UMASD)method was developed for extraction of essential oil(EO)from dry Schisandra chinensis.The factors of UMASD which influenced the extraction yield were studied.The optimal conditions were determined as: microwave power 500 W,ultrasonic power300 W,microwave irradiation time 30 min and ultrasonic irradiation time 20 min.The composition of the EOs extracted by steam distillation(SD)and UMASD was analyzed and compared by gas chromatography-mass spectrometry.With UMASD method,not only has the extraction time been shortened to 30 min(hydro-distillation 6.0 h for extracting EO),but also the extraction efficiency has been improved.It reduced the energy consumption of the extraction process and the identified compounds were more than any other methods.According to the results,UMASD was proved to be a simple,environmental friendly and effective preparation method for the analysis of the EO in Schisandra chinensis and could be potentially extended to target analytes in other plants.2.With soybean as the research subject,the ultrasound/microwave assisted one-step extraction-derivatization method(UMAED)combined with gas chromatographymass spectrometry was established for the determination of the fatty acids(FAs)profile.The factors which affected the efficiency of esterification of triglycerides,including ultrasonic power,microwave power,temperature,amount of methanol and catalyst,extraction time,were optimized by single factor experiments.On the basis of single factor experiments,the critical experimental parameters for the UMAED(microwave power,temperature,amount of methanol and catalyst)were optimized with response surface Box-Behnken design methodology by taking the ratio of the total peak area of fatty acid methyl ester and the internal standard substance of lauric acid methyl ester as a major response index.Then the fatty acids of 9 kinds of beans,which were soybeans,rice beans,kidney beans,red kidney beans,red beans,black beans,black cowpea,mung beans and zebra beans,were analyzed on the optimal experimental condition.It showed that this method is rapid and efficient.The extraction efficiency was higher and need less energy consumption.The method will have important practical value in the future.3.Guizhou tobacco was chosen as the experiment object,using ultrasound/microwave assisted extraction coupled to headspace solid-phase microextraction(UMAE-HS-SPME)combined with gas chromatography-mass spectrometry for the analysis of the volatile compounds.The factors of UMAE-HS-SPME which influenced the extraction yield were studied.The optimal conditions were determined as: microwave power 600 W,ultrasonic power 100 W,extraction time10 min and extraction temperature 110 ?.The qualitation and quantitation of the volatile components were compared by different methods which were microwave assisted extraction coupled to headspace solid-phase microextraction(MAE-HS-SPME),headspace solid-phase microextraction(HS-SPME)and UMAE-HSSPME.Then the volatile compounds of other three kinds of different origin tobacco were detected using UMAE-HS-SPME.The results showed that UMAE-HS-SPME is a rapid,efficient,energy-saving and environmental method.It can be used to measure more volatile constituents in tobacco,especially the components with high boiling point.