title: Analysis of street cocaine samples in nasal fluid by Raman spectroscopy.
abstract: The principal objective of this work was to demonstrate the capability of Raman spectroscopy to detect small amounts of cocaine in nasal fluid, and to identify the main drug and the most widely used cutting agents. Initially, standard samples were analysed and sampling conditions were studied by comparing different swabs used for the sample collection. Once the most appropriate swab was selected, which permitted a relatively simple detection of the standard cocaine hydrochloride, qualitative analyses of real samples were carried out. Three street cocaine samples were analysed, and the presence of cutting substances was highlighted by the appearance of different bands not corresponding to the ones of the standard cocaine. To identify the substances present in each sample, the spectra of the street cocaine samples were collected and compared with a digital library created on purpose with the spectra of the most common cutting agents. In this case, correlation coefficients permitted to recognize the most important substances presumably present in the samples, and gave an estimation of the purity of the cocaine. However, when nasal fluid was present, its strong signal could overlap or interfere with the smaller signal of the cutting substances, hindering their identification.
authors.affiliation: Department of Analytical Chemistry, Physical Chemistry and Chemical Engineering, and University Institute of Research in Police Sciences (IUICP), University of Alcalá, Ctra. Madrid-Barcelona Km. 33.6, 28871 Alcalá de Henares, Madrid, Spain. Electronic address: valentina.d@uah.es.
authors.forename: Valentina
authors.initials: V
authors.lastname: D'Elia
authors.affiliation: Department of Analytical Chemistry, Physical Chemistry and Chemical Engineering, and University Institute of Research in Police Sciences (IUICP), University of Alcalá, Ctra. Madrid-Barcelona Km. 33.6, 28871 Alcalá de Henares, Madrid, Spain. Electronic address: gemma.montalvo@uah.es.
authors.forename: Gemma
authors.initials: G
authors.lastname: Montalvo
authors.affiliation: Department of Analytical Chemistry, Physical Chemistry and Chemical Engineering, and University Institute of Research in Police Sciences (IUICP), University of Alcalá, Ctra. Madrid-Barcelona Km. 33.6, 28871 Alcalá de Henares, Madrid, Spain. Electronic address: carmen.gruiz@uah.es.
authors.forename: Carmen García
authors.initials: CG
authors.lastname: Ruiz
mesh_terms: D003042:Cocaine / Q000032:analysis*; D013287:Illicit Drugs; D009093:Mucus; D013059:Spectrum Analysis, Raman
chemical_list: D013287:Illicit Drugs; D003042:Cocaine
keywords: Cocaine; Cutting agents; Nasal fluid; Raman spectroscopy