Quantitative Analysis Of Chemical Compositions Of Low Cellulosic Plant Materials

With the development of technology,the ecological environment is suffered more and more serious damages.People desire that the renewable and biodegradable resources develop rapidly.The plant materials get into the people's vision and many researchers launch a lot of research work for the materials.In order to the comprehensive utilization of plant materials,we must complete the work that accurate determination of the chemical composition.The course researches the maize bracts,rice straw and Carex meyeriana and analyzes the existing methods of the quantitative analysis of chemical components and the modern instrumental analysis and makes clear the characteristics and existing defects.What the main work is to optimize the existing problems of experiment and verify the feasibility of the proposed method and put the optimization method is suitable for maize bracts,rice straw and Carex meyeriana.The main contents of this paper include:(1)The research project analyzes three kinds of plant materials by three kinds of traditional chemical composition analysis methods.Through the experimental operation found that: when we use the ramie chemical composition quantitative analysis method to analyze the chemical compositions,the fat and wax contents will be unstable.The soluble pectin will be hydrolyzed in the process of detecting water soluble substance.Some of the hemicellulose will also be hydrolyzed in the process of detecting water soluble substance and pectin.Some alkaline lignin will be hydrolyzed in the process of detecting hemicellulose.And the cellulose content is influenced by the result of other components.When we use the Van Soest analysis method to analyze the chemical compositions,the leached foam will be increased and the efficiency is decreased.The content of lignin and ash is fewer than normal content.When we use the papermaking raw material analysis method to analyze the chemical compositions,the pentosan is a part of hydrolysis products of hemicellulose.And the hemicellulose and cellulose content cannot be detected correctly.The pectin extraction is not complete and hemicellulose loss will be happened.(3)The paper optimizes the chemical composition quantitative analysis method of plant materials.The main experimental components include: fat and wax,water soluble substance and pectin,lignin,hemicellulose,cellulose.The optimization of the fat and wax test is based on the ramie chemical composition quantitative analysis method.And the experimental parameters is optimized.To ensure that the fat and wax were extracted completely and avoid the unstable results,the extraction time is optimized for 5h and the air drying time is optimized for 24 h.The optimizations of the water soluble substance and pectin include: the extraction time is 6h,the extraction solution capacity of 300 ml,and the temperature of the water bath of maize bracts,rice straw and Carex meyeriana were 80?,90?,100?.The absorbance of galacturonic acid is measured by UV spectrophotometer,and the content of pectin and water soluble substance are calculated.The determination of lignin is by the ramie chemical composition quantitative analysis method.The determination of hemicellulose and cellulose is divided into two steps.Firstly,to put samples into the hot alkali solution and the weight loss is the content W1 of hemicellulose and alkali lignin.Secondly,to put the extracted sample into H2SO4 and the weight loss is the content of cellulose.The extracted sample is alkali-insoluble lignin.The lignin content is the total lignin content minus the alkali-insoluble lignin content and the hemicellulose content is W1 minus the lignin content.In this paper,the optimization method the course put is suitable for maize bracts,rice straw and Carex meyeriana.To provide a selection for the comprehensive application of plant materials.