Análise multivariada e espectroscopia no infravermelho aplicadas em análises forenses: drogas e medicamentos

Abstract

Court cases must be sustained in solid evidences, thus forensic analysis of seized products, such as illicit drugs and counterfeit medicines, must be performed. Consequently, new rapid and reliable analytical methods must be developed. This thesis introduces qualitative analytical methods based on attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and two supervisedclassification chemometric methods, partial least squares discriminant analysis (PLSDA) and soft independent modeling by class analogy (SIMCA). Illegal drugs are responsible for most of the analyses in forensic chemistry laboratories. So, two methods were developed to identify synthetic drugs: one for blotter samples and other for ecstasy-like tablets. A third method was developed for the analysis of counterfeit medicines (sildenafil), which is an important group of seized samples forforensic chemistry. Each method was validated to prove its effectiveness. Reliability rates of the methods for drugs in blotters, drugs in tablets and counterfeit medicines were 86.2%, 100% e 96.4%, respectively. The developed methods are rapid and produce objective results, which are desirable features of forensic analysis methods.