title: A fast screening MALDI method for the detection of cocaine and its metabolites in hair.
abstract: Matrix-assisted laser desorption/ionisation (MALDI) mass spectrometry was used for the rapid detection of cocaine, benzoylecgonine and cocaethylene in hair. Different MALDI sample preparation procedures have been tested and the employment of a multi-layer 'graphite-sample-electrosprayed alpha-cyano-4-hydroxycinnamic acid (HCCA)' yielded the best results for standard solutions of the target analytes. The same approach was subsequently applied to hair samples that were known to contain cocaine, benzoylecgonine and cocaethylene, as determined by a classical GC-MS method. It was however necessary to extract hair samples by incubating them in methanol/trifluoroacetic acid for a short time (15 min) at 45 degrees C; 1 microl of the obtained supernatant was deposed on a metal surface treated with graphite, and HCCA was electrosprayed on it. This procedure successfully suppressed matrix peaks and was effective in detecting all the target analytes as their protonated species. The results obtained give further confirmation of the effectiveness of the MALDI for detecting drugs and their metabolites in complex biological matrices. The method can be useful as a fast screening procedure to detect the presence of cocaine and metabolites in hair samples.
authors.affiliation: Forensic Toxicology and Antidoping Unit, University Hospital of Padova, Padova, Italy.
authors.forename: Susanna
authors.initials: S
authors.lastname: Vogliardi
authors.forename: Donata
authors.initials: D
authors.lastname: Favretto
authors.forename: Giampietro
authors.initials: G
authors.lastname: Frison
authors.forename: Santo Davide
authors.initials: SD
authors.lastname: Ferrara
authors.forename: Roberta
authors.initials: R
authors.lastname: Seraglia
authors.forename: Pietro
authors.initials: P
authors.lastname: Traldi
mesh_terms: D003042:Cocaine / Q000031:analogs & derivatives* / Q000032:analysis* / Q000378:metabolism*; D003373:Coumaric Acids / Q000737:chemistry; D006197:Hair / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D000432:Methanol / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D015813:Substance Abuse Detection / Q000379:methods; D013696:Temperature; D013997:Time Factors; D014269:Trifluoroacetic Acid / Q000737:chemistry
chemical_list: D003373:Coumaric Acids; C007175:alpha-cyano-4-hydroxycinnamate; C005618:benzoylecgonine; D014269:Trifluoroacetic Acid; C066444:cocaethylene; D003042:Cocaine; D000432:Methanol