Study On The Application Of The Analysed Of Volatile Components In Maca

Volatile components mainly refers to the organics matter that the melting point is lower than the room temperature,but the boiling point is between 50℃ to 260 ℃.They can found widely in a variety of plants,which is an essential part of the plants.At the same time,volatile components can be found all around our daily life,such as the flowers,trees,soil,atmosphere,water and so on.Due to the complex matrix low content of some target,the analysis of the volatile components in the samples generally involves two steps:pretreatment and detection.Pretreatment as an essential step in the analysis process,domestic and foreign scholars had done a series of research.Now,the common pretreatment methods of the volatile components are include extraction,supercritical fluid extraction,headspace extraction,solid-phase micro-extraction,simultaneous distillation extraction and so on.Solid phase micro-extraction is simple and without organic solvents was used;solvent extraction is also simple and can be got a higher recovery rate.The main research contents of this paper are as follows:(1)Study on the application of volatile components in analysed of Maca by headspace-so lid-phase micro-extraction-gas chromatography/mass spectrometryHeadspace-solid phase micro-extraction had advantage of sampled,extracted,concentrated and injected,the solid samples can be directly added to the sample bottle during experiment,which can effectively prevent the loss of volatile components to ensure the accuracy of the experiment.In this chapter,the five conditions of headspace-solid phase micro-extraction(HS-SPME)were optimized(solid phase extraction head,extraction temperature,extraction time,desorption time,equilibrium time).Under the optimal conditions,the volatile and semi-volatile components of Maca from five places were detected by headspace-solid-phase micro-extraction-gas chromatography/mass spectrometry(SPME-GC/MS).The standard deviation of this method ranged from 0.58%to 50.20%,94 kinds of volatile and semi-volatile components were determined of Maca from five places.(2)Study on the application of volatile components in analysed of Maca by Stir-bar sorptive extraction-thermal desorption-gas chromatography/mass spectrometryStir-bar sorptive extraction-thermal desorption was developed in recent years,Stir-bar was used to adsorpted and concentrated for the samples,thermal desorption could removed the impurity compounds.And the solid samples,liquid samples,gas samples can be directly adsorbed with this technology.The same extraction method under different conditions could made a great influence on the detection results.During this experiment,the conditions of adsorption and the conditions of thermal desorption were optimized by single factor method,and under the optimal conditions,the volatile and semi-volatile components of Maca from five places were tested by Stir-bar sorptive extraction-thermal desorption-gas chromatography/mass spectrometry(SBSE-TD-GC/MS).There were 66 kinds volatile and semi-volatile were detected of Maca from five places,the relative standard deviation between 0.22-13.56%.It can be seen from results of the discussion,the volatile components was different of Maca from different places,and the amount of the common constituents were also different of Maca from different places.(3)The differences in volatile constituents of Maca from different placesThe volatile substances of Maca from different places was different,in order to more specifically discussed the difference,the same method was used during the experiment of Maca.SPME-GC-MS combined with internal standard method was determined as a semi-quantitative estimation method to detect the volatile components of Maca in five different places.The internal standard was optimized during this experiment process.At last,spss was used to analyzed the difference between the Maca of five places,and it was shown that the difference between them was obvious.(4)The differences between the volatile components of Maca by different pre-treatment methodsIn order to explored the effect of different pretreatment methods on the detection results,Maca from five different places were extracted by simultaneous distillation extraction(SDE),and the components were identified by gas chromatography-mass spectrometry during this experiment,There were 39 kinds of volatile components were determined;Then,the results of HS-SPME-GC/MS and SBSE-TD-GC/MS were compared with the results of SDE-GC/MS.As the result was shown,the detect results were different under different pre-treatment methods.This is mainly because of the extraction of the material composition is different under different pre-treatment method.