Ramie Chemical Composition Based On Near Infrared Technology For Rapid Quantitative Analysis

As a plant fiber material,ramie is widely used in textile industry.Ramie must be degummed before it can be used as textile fiber.Accurate and fast quantitative analysis in the chemical composition of raw ramie is a rational basis of establishing degumming process.Meanwhile,fast forecasting of chemical composition and content of ramie has important guiding role in ramie varieties optimization in the field of agricultural. Therefore,quantitative chemical composition analysis method of natural plant fiber was studied and improved and near infrared spectrum of ramie was tested by AOTF near infrared spectrometer.After that,the prediction model of chemical compositon content of ramie was established using multivariate calibration method combined with the chemical composition content which analysised by improved method.Thereby carry out the rapid prediction of certain chemical composition content of ramie and put forward improved measures for other unpredictable composition analysis methods in order to accurate predict these compositions in the further work.Put forward several quantitative analysis methods in order to modify GB/T5889-86 "ramie chemical composition of quantitative analysis method",a relative accuracy of chemical quantitative analysis method has been optimized by experiment.The optimised method was as follows:firstly,wrap the crushed plants in the bolting cloth,extracte lipid with Carbon tetrachloride & alcohol in Soxhletsextractor,distill the extracted liquid,then have the residue dried and weighed as wax content;secondly,water soluble matters content was analyzed in boiling water,content of pectin was determined using ammonium oxalate,the total content of hemicelluloses and partial liguin was tested using sodium hydroxide and hemicelluse content can be calculated after delignification;at last, content of cellulose was obtained after the residue was treated in acetic acid and sodium chlorite aqua to remove lignin.Liguin content has been determined by sulphuric acid.The result shows that this method is accurate and it has wide application in chemical composition analysis of plants.Chemical compositions of 60 ramies were quantitatively analyzed using the above optimized method.At the same time,near infrared spectrums of this 60 samples were scanned by AOTF near infrared spectrometer and the obtained spectrums were first derivated.The prediction model of chemical compositon content of ramie was established by PLS1 according to the result of chemical analysis and near infrared spectrums.The prediction model was validated by several samples.The results show that:those hemicelluloses,cellulose and gun content which content are more than 10%has establisted the fast and accurate predict model,they can predict the hemicelluloses,cellulose and gun content fast and accurate;the macroconstituent such as water soluble matters,pectin and ash have established prediction models which can be do the predicting work,but a little difference has exit too,more samples can help to increase the accuracy of the predict model;the microconstituents such as wax and ligin has established stable models but poor prediction ability due to inaccuracy chemical analysis and less number of samples,more accurate chemical analysis method and more samples are needed to establish a accurate predition model.