Easy To Precursor Chemicals Acetic Anhydride Origin Identification Is A Preliminary Study

Acetic anhydride is a kind of precursor chemicals which is strictly controlled by UN Convention Against Illict Traffic in Narcotic Drugs and Psychotropic Substances and Chinese laws.In recent years,many cases of illegal buying,selling and smuggling of precursor chemicals occure in China,this seriously damages our international image and prestige.So it is necessary to build the methods for measuring inorganic elements and organic components, also it is necessary to build the methods for building model and variable selection method,and accordingly build the "fingerprint" of different acetic anhydride manufacturers,therefore identifying the unknown acetic anhydride samples.This is very significant to crack down illegal buying,selling and smuggling of acetic anhydride.The main content of this dissertation is:1.The method for inorganic elements detection in acetic anhydride by ICP-MS is preliminarily established.The impacts for determination result by sample weights,digestion system and the measurement mode of ICP-MS are extensively investigated.The detection limits are 0.00016～1.6 ng·g^-1 while the relative standard deviations are 0.16%～5.93%,and the recovery rates of elements are between 84.3%-116.6%.2.Good classification result of different acetic anhydride sources is obtained by building model of five different sources acetic anhydride samples with PLS classification method, based on the quantitative data of acetic anhydride samples determined by ICP-MS.Combined with VIP plot in PLS model and variable W*C[1]/W*C[2]planar graph,we find out the 12 kinds of elements which have least contribution rate for the model,thus simplify it effectively. This provides theoretical and technical support for increasing the sample sizes and building the inorganic fingerprint of different acetic anhydride manufacturers.3.Characteristic peak and chemical components of different sources acetic anhydride are preliminarily analyzed by GC-MS,which validates the feasibility of analyzing characteristic peak in acetic anhydride by GC-MS.4.Trace inorganic elements in heroin samples are analyzed by ICP-MS,and such data is processesed by cluster analysis with SPSS software,therefore different sources of heroin is distinguished.It reveals the relationship between the sources of heroin and contents of trace elements by component analysis.This information will be important basis for identifying different sources heroin.