title: Rapid determination of recent cocaine use with magnetic particles-based enzyme immunoassays in serum, saliva, and urine fluids.
abstract: Cocaine is one of the most worldwide used illicit drugs. We report a magnetic particles-based enzyme-linked immunoassay (mpEIA) method for the rapid and sensitive determination of cocaine (COC) in saliva, urine and serum samples. Under optimized conditions, the limits of detections were 0.09ngmL(-1) (urine), 0.15ngmL(-1) (saliva), and 0.06ngmL(-1) COC (human serum). Sensitivities were in the range EC50=0.6-2.5ngmL(-1) COC. The cross-reactivity with the principal metabolite benzoylecgonine (BZE) was only 1.6%. Recovering percentages of doped samples (0, 10, 50, and 100ngmL(-1) of COC) ranged from about 86-111%. Some advantages of the developed mpEIA over conventional ELISA kits are faster incubations, improved reproducibility, and consumption of lower amounts of antibody and enzyme conjugates due to the use of magnetic beads. The reported method was validated following the guidelines on bioanalytical methods of the European Medicines Agency (2011). Unmetabolized COC detection has a great interest in pharmacological, pharmacokinetics, and toxicokinetics studies, and can be used to detect a very recent COC use (1-6h).
authors.affiliation: Analytical Spectroscopy and Sensors Group (GEAS), Institute of Environmental Sciences (IUCA), University of Zaragoza, C/Pedro Cerbuna, 12, 50009 Zaragoza, Spain. Electronic address: jcvidal@unizar.es.
authors.forename: Juan C
authors.initials: JC
authors.lastname: Vidal
authors.affiliation: Analytical Spectroscopy and Sensors Group (GEAS), Institute of Environmental Sciences (IUCA), University of Zaragoza, C/Pedro Cerbuna, 12, 50009 Zaragoza, Spain.
authors.forename: Juan R
authors.initials: JR
authors.lastname: Bertolín
authors.affiliation: CAPHER IDI S.L., C/Ermesinda de Aragón, 4, c116, 50012 Zaragoza,Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Bonel
authors.affiliation: Analytical Chemistry Department, Faculty of Sciences, University of Burgos, Pza. Misael Bañuelos s/n, 09001 Burgos, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Asturias
authors.affiliation: Analytical Chemistry Department, Faculty of Sciences, University of Burgos, Pza. Misael Bañuelos s/n, 09001 Burgos, Spain.
authors.forename: M Julia
authors.initials: MJ
authors.lastname: Arcos-Martínez
authors.affiliation: Analytical Spectroscopy and Sensors Group (GEAS), Institute of Environmental Sciences (IUCA), University of Zaragoza, C/Pedro Cerbuna, 12, 50009 Zaragoza, Spain.
authors.forename: Juan R
authors.initials: JR
authors.lastname: Castillo
mesh_terms: D003042:Cocaine / Q000032:analysis* / Q000097:blood / Q000652:urine; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D057230:Limit of Detection; D008280:Magnetics; D012463:Saliva / Q000737:chemistry*
chemical_list: D003042:Cocaine
keywords: Benzoylecgonine; Biological samples; Cocaine; Drugs of abuse; Magnetic particles-based enzyme immunoassay; Pharmacokinetics