Application Research Of New In-situ Analysis Technology In Ink Marking Of Ballpoint Pens

Ballpoint pen is a widely used writing tool in people's daily life.It often appears in some official and legal documents such as company contracts,unit documents,personal certifications,etc.In the field of document judicial identification,there is about ballpoint pen writing.The identification of materials is endless,accounting for a large proportion of the identification.In many civil cases,the identification of ballpoint pen tampering documents requires a more accurate classification of ingredients.In criminal cases,the traceability of the ballpoint pen ink is also detected by the case.The essential.Therefore,the rapid qualitative analysis of ballpoint pen components can greatly help the investigation of actual cases.How to quickly and non-destructively perform qualitative detection and classification of test materials is a very worthwhile issue.Especially for the identification of tampered documents of ballpoint pen writing materials,it has been a big problem in the identification of documents for a long time.Distinguishing the differences in the ink composition of ballpoint pens has a very important role in the identification of documents.Because the composition of ballpoint pen inks is more complex,and the composition of ballpoint pen inks of different brands,different manufacturers,and different models is often not large,especially domestic ballpoint pens are mostly lacking in innovation in composition,so they want to stay in place Obtaining better results under non-destructive testing conditions is quite difficult,which also makes the identification and classification of ballpoint pen ink components a problem that has been widely concerned in the industry.Chapter 1 of the thesis explores the background of the topic selection,introduces the origin and use of ballpoint pens,the composition of different types of ballpoint pens,the research methods and research status of ballpoint pen components,summarizes the current research technology in the field,and clarifies the composition of ballpoint pens.Discriminates the importance in the field of forensic identification of documents,and introduces the purpose and significance of this topic.Chapter 2 uses surface-enhanced Raman spectroscopy(SERS)to analyze 28 blue ballpoint pens and 29 black ballpoint pens from different manufacturers,different types and brands,while optimizing the experimental scheme,combining three excitation light wavelengths of 785 nm,633nm and 514 nm Based on the detection data below,the classification data of the three wavelengths were combined and optimized for the first time,and the analysis method of surface enhanced Raman spectroscopy(SERS)technology was established.The third chapter uses real-time direct analysis-high resolution mass spectrometry(DART-HRMS)to analyze 28 blue ballpoint pens and 29 black ballpoint pens from different manufacturers,different types and brands,and optimize the experimental scheme,and explore different ionization temperatures.The impact on the ballpoint pen ink analysis results,so the appropriate method was selected for analysis.According to the mass spectrometry results of each ballpoint pen and combined with chemometric methods,the real-time direct analysis-high resolution mass spectrometry(DART-HRMS)Technical analysis methods.Chapter 4 verifies the authenticity of the tampered document identification process,verifies the reliability of the two analysis methods established in the previous two chapters,compares them with conventional identification and inspection methods,and explores the role of the methods established in this paper in practical cases.,To verify the science and stability of new technologies in practice.