title: Profiling cocaine by ATR-FTIR.
abstract: In this article, five hundred and thirteen cocaine seizures of the State of Rio Grande do Sul (Brazil) were analyzed by Fourier transform infrared spectroscopy (FT-IR) in the fingerprint region (1800-650 cm(-1)) to profiling and evaluate the pharmaceutical products used as adulterants. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) were used to identify patterns among the samples whereas partial least square discriminant analysis (PLS-DA) and support vector machines discriminant analysis (SVM-DA) were used to classification the cocaine between base and salt. Spectra of standard solid mixtures of cocaine (salt and base), phenacetin, lidocaine and caffeine were used associated with PCA to predict qualitatively the profile of cocaine seizure. In HCA and PCA, salt and base group were formed correctly. Accordingly with predicted profile of the salt samples, they were majority adulterated with caffeine and lidocaine whereas base cocaine was adulterated only with phenacetin. In the discrimant analysis, all methods have classified the cocaine samples correctly with sensitivity and specificity equal to one between salt and base.
authors.affiliation: Instituto de Química, Universidade Federal do Rio Grande do Sul, Brazil.
authors.forename: M C A
authors.initials: MC
authors.lastname: Marcelo
authors.affiliation: Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Brazil.
authors.forename: K C
authors.initials: KC
authors.lastname: Mariotti
authors.affiliation: Instituto de Química, Universidade Federal do Rio Grande do Sul, Brazil; Instituto Nacional de Ciência e Tecnologia de Bioanalítica, Campinas, SP, Brazil.
authors.forename: M F
authors.initials: MF
authors.lastname: Ferrão
authors.affiliation: Setor Técnico-Científico da Superintendência da Polícia Federal no Rio Grande do Sul, Brazil. Electronic address: rafaelortiz.rso@dpf.gov.br.
authors.forename: R S
authors.initials: RS
authors.lastname: Ortiz
mesh_terms: D002110:Caffeine / Q000032:analysis; D016000:Cluster Analysis; D003042:Cocaine / Q000737:chemistry*; D016002:Discriminant Analysis; D018765:Dopamine Uptake Inhibitors / Q000737:chemistry*; D004340:Drug Contamination; D006801:Humans; D008012:Lidocaine / Q000032:analysis; D010615:Phenacetin / Q000032:analysis; D025341:Principal Component Analysis; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D018765:Dopamine Uptake Inhibitors; D002110:Caffeine; D008012:Lidocaine; D010615:Phenacetin; D003042:Cocaine
keywords: Attenuated total reflectance; Chemical profile; Cocaine; Fourier transform infrared spectroscopy