title: Thin layer chromatography coupled to paper spray ionization mass spectrometry for cocaine and its adulterants analysis.
abstract: Thin layer chromatography (TLC) is a simple and inexpensive type of chromatography that is extensively used in forensic laboratories for drugs of abuse analysis. In this work, TLC is optimized to analyze cocaine and its adulterants (caffeine, benzocaine, lidocaine and phenacetin) in which the sensitivity (visual determination of LOD from 0.5 to 14mgmL(-1)) and the selectivity (from the study of three different eluents: CHCl3:CH3OH:HCOOHglacial (75:20:5v%), (C2H5)2O:CHCl3 (50:50v%) and CH3OH:NH4OH (100:1.5v%)) were evaluated. Aiming to improve these figures of merit, the TLC spots were identified and quantified (linearity with R(2)>0.98) by the paper spray ionization mass spectrometry (PS-MS), reaching now lower LOD values (>1.0μgmL(-1)). The method developed in this work open up perspective of enhancing the reliability of traditional and routine TLC analysis employed in the criminal expertise units. Higher sensitivity, selectivity and rapidity can be provided in forensic reports, besides the possibility of quantitative analysis. Due to the great simplicity, the PS(+)-MS technique can also be coupled directly to other separation techniques such as the paper chromatography and can still be used in analyses of LSD blotter, documents and synthetic drugs.
authors.affiliation: Instituto de Química, Universidade Federal de Goiás, 74001-970 Goiânia, GO, Brazil.
authors.forename: Thays C
authors.initials: TC
authors.lastname: De Carvalho
authors.affiliation: Laboratório de Petroleômica e Química Forense, Departamento de Química, Universidade Federal do Espírito Santo, 29075-910 Vitória, ES, Brazil.
authors.forename: Flavia
authors.initials: F
authors.lastname: Tosato
authors.affiliation: Laboratório de Petroleômica e Química Forense, Departamento de Química, Universidade Federal do Espírito Santo, 29075-910 Vitória, ES, Brazil.
authors.forename: Lindamara M
authors.initials: LM
authors.lastname: Souza
authors.affiliation: Laboratório de Petroleômica e Química Forense, Departamento de Química, Universidade Federal do Espírito Santo, 29075-910 Vitória, ES, Brazil.
authors.forename: Heloa
authors.initials: H
authors.lastname: Santos
authors.affiliation: Laboratório de Química Legal, Superintendência de Polícia Técnico-Científica da Polícia Civil do Estado do Espírito Santo, 29045-300 Vitória, ES, Brazil.
authors.forename: Bianca B
authors.initials: BB
authors.lastname: Merlo
authors.affiliation: Superintendência de Polícia Federal no Estado do Rio Grande do Sul, 90160-093 Porto Alegre, RS, Brazil.
authors.forename: Rafael S
authors.initials: RS
authors.lastname: Ortiz
authors.affiliation: Laboratório de Petroleômica e Química Forense, Departamento de Química, Universidade Federal do Espírito Santo, 29075-910 Vitória, ES, Brazil.
authors.forename: Rayza R T
authors.initials: RR
authors.lastname: Rodrigues
authors.affiliation: Laboratório de Petroleômica e Química Forense, Departamento de Química, Universidade Federal do Espírito Santo, 29075-910 Vitória, ES, Brazil.
authors.forename: Paulo R
authors.initials: PR
authors.lastname: Filgueiras
authors.affiliation: Instituto Federal do Espírito Santo, 29106-010 Vila Velha, ES, Brazil.
authors.forename: Hildegardo S
authors.initials: HS
authors.lastname: França
authors.affiliation: Departamento de Química, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, MG, Brazil.
authors.forename: Rodinei
authors.initials: R
authors.lastname: Augusti
authors.affiliation: Laboratório de Petroleômica e Química Forense, Departamento de Química, Universidade Federal do Espírito Santo, 29075-910 Vitória, ES, Brazil; Instituto Federal do Espírito Santo, 29106-010 Vila Velha, ES, Brazil. Electronic address: wandersonromao@gmail.com.
authors.forename: Wanderson
authors.initials: W
authors.lastname: Romão
authors.affiliation: Instituto de Química, Universidade Federal de Goiás, 74001-970 Goiânia, GO, Brazil; Laboratório de Petroleômica e Química Forense, Departamento de Química, Universidade Federal do Espírito Santo, 29075-910 Vitória, ES, Brazil. Electronic address: bonigontijo@yahoo.com.br.
authors.forename: Boniek G
authors.initials: BG
authors.lastname: Vaz
mesh_terms: D001566:Benzocaine / Q000032:analysis; D002110:Caffeine / Q000032:analysis; D002855:Chromatography, Thin Layer; D003042:Cocaine / Q000737:chemistry*; D004340:Drug Contamination; D006801:Humans; D008012:Lidocaine / Q000032:analysis; D013058:Mass Spectrometry / Q000379:methods; D009294:Narcotics / Q000737:chemistry*; D010615:Phenacetin / Q000032:analysis
chemical_list: D009294:Narcotics; D002110:Caffeine; D008012:Lidocaine; D010615:Phenacetin; D003042:Cocaine; D001566:Benzocaine
keywords: Cocaine; PS-MS; Paper spray ionization; TLC