Identification and quantification of 35 psychotropic drugs and metabolites in hair by LC-MS/MS: application in forensic toxicology.
Despite a non-invasive sampling, hair samples are generally collected in limited amounts for an obvious esthetic reason. In order to reduce the required quantity of samples, a multianalytes method allowing simultaneous identification and quantification of 35 psychoactive drugs was developed. After incubation of 50 mg of hair in a phosphate buffer pH 5 for one night at room temperature, the substances of interest were extracted by a simple liquid-liquid extraction step, with a dichloromethane/ether mixture (70:30, v/v). After evaporation under a gentle stream of nitrogen and reconstitution in formate buffer (2 mM, pH 3)/acetonitrile (90:10, v/v), twenty microliter were injected into the LC-MS/MS system for a chromatographic run of 29 min using an Atlantis T3 column (150 × 2.1 mm, 3 μm) (Waters Corp, Milford, USA) and a gradient mixture of 2 mM, pH 3.0 ammonium formate, and 2 mM, pH 3.0 ammonium formate/acetonitrile. The data acquisition was performed in scheduled MRM mode. Intra- and inter-day precisions, estimated using the coefficient of variation and relative bias, were lower than 20 % for all concentration levels, except for two compounds. The limits of detection and quantification ranged from 0.5 to 10 pg/mg. After complete validation, this method has been successfully used in several forensic cases, three of which are reported.
Department of Pharmacology and Toxicology, University Hospital, 2 avenue Martin Luther King, 87042, Limoges, France.
Julie
J
Maublanc
Sylvain
S
Dulaurent
Julien
J
Morichon
Gérard
G
Lachâtre
Jean-michel
JM
Gaulier
D002851:Chromatography, High Pressure Liquid; D002998:Clonazepam / Q000031:analogs & derivatives / Q000032:analysis; D005445:Flunitrazepam / Q000031:analogs & derivatives / Q000032:analysis; D053593:Forensic Toxicology; D006197:Hair / Q000737:chemistry*; D006801:Humans; D057230:Limit of Detection; D011619:Psychotropic Drugs / Q000032:analysis*; D053719:Tandem Mass Spectrometry
D011619:Psychotropic Drugs; C020860:7-aminoclonazepam; D002998:Clonazepam; D005445:Flunitrazepam; C036343:7-aminoflunitrazepam