LIBS Combined With Chemometric Methods To Trace The Origin Of Angelica

Traditional Chinese medicine is an indispensable raw material for the treatment of traditional Chinese medicine,which comes from traditional Chinese medicine from different places,because of its growth environment(temperature,humidity,light),artificial care and other factors,it will lead to great differences in the content of elements and organic components(quality markers)in Chinese medicinal materials from different areas,thus affecting their efficacy.Trace element analysis and origin traceability can not only solve the problem of mixed use of traditional Chinese medicine from different areas,but also provide data support for pharmacological research.Laser-induced breakdown spectroscopy(LIBS),as an emerging technology for medicinal materials detection,has the advantages of micro-loss,in-situ analysis,and multi-element combined measurement.This article is based on LIBS technology and applied it to the traceability of the origin of Chinese medicinal materials and the analysis of trace elements in Chinese medicinal materials.Mainly carried out the following work:(1)Selected Chinese angelica medicinal materials from 5 producing areas in Sichuan,Hubei,Yunnan,Guizhou,and Gansu as the research objects.Set up the LIBS experimental device.In order to obtain stable and reliable data in the experiment,the laser energy,delay time,and focus position in the experiment were optimized;(2)In order to compare traditional traceability methods,highlight the advantages of LIBS combined with chemometric methods.The microscopic identification of Angelica sinensis from five producing areas showed that although the appearance of Angelica sinensis from different producing areas was indistinguishable,the size of oil chamber(quality marker)could be used to identify some producing areas,but this result was based on experience and took a long time,so it was difficult to trace the origin;(3)Traditional Chinese medicine is rich in trace elements,in order to verify the advantage of Chemometrics in the quantitative analysis of trace elements in traditional Chinese medicine.The contents of Ca and Mg in Angelica sinensis were determined by inductively coupled plasma mass spectrometry(ICP-MS).The standard curve and two chemometric models were established.By comparing the standard curve with the chemometric prediction error,it was concluded that the chemometric error was far less than the standard curve;(4)In order to solve the problem of multi origin Angelica tracing.using LIBS technology and 3 kinds of chemometrics methods,LIBS technology provides modeling variables,through grid search optimization of c and g in the support vector machine,particle swarm optimization method of mtry and ntree in the random forest,so that the establishment The model is more robust.Finally,the modeling result of the producing area is that the principal component analysis overlaps seriously,and the result is difficult to trace to the source.The traceability accuracy of support vector machine and random forest is 92% and 87.2%,respectively.The results can provide data basis for origin traceability.