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.

Analytical findings of an acute intoxication after inhalation of methoxetamine.

Methoxetamine (MXE) is increasingly used and abused, as it is frequently presented as being safer than ketamine, and legal. Cases of only MXE consumption being associated with the occurrence of seizures are rarely reported. A single MXE intoxication case by inhalation is described concerning a 21-year-old man, not known to be epileptic, who was found collapsed in his bedroom, supposedly after an epileptic seizure. He was transferred to the Emergency Department of the Henri Mondor Hospital, Aurillac, France. He was conscious, but with a sinus bradycardia (48/min) and an ST-segment elevation on the electrocardiogram, and a slightly increased creatine kinase level (270 U/L) and hyponatremia (127 mmol/L). New seizure activity occurred during hospitalization, but the clinical course in the intensive care unit was favorable. Quantitation of MXE in serum and urine using gas chromatography coupled to mass spectrometry (GC-MS) was developed, as well as a liquid chromatography coupled to tandem mass spectrometry (LC-MS-MS) method for the determination of MXE in hair. Limits of detection and quantification were, respectively, 2 and 10 µg/L for the GC-MS method and both 0.5 pg/mg for the LC-MS-MS method. Concentrations of 30 and 408 µg/L were, respectively, measured in serum and urine. Concentrations of 135 and 145 pg/mg were detected in two 2.5 cm hair strands, consistent with one or several consumptions during the 2 ½ months prior to sampling. A sample of the powder consumed was available and also analyzed. This case illustrates the dangers of this drug, which justify its classification as a narcotic in France since August 2013.

LSD in pubic hair in a fatality.

Lysergic acid diethylamide (LSD) is a potent hallucinogen, active at very low dosage and its determination in body fluids in a forensic context may present some difficulties, even more so in hair. A dedicated liquid chromatography-electrospray-tandem mass spectrometry (LC-ES-MS/MS) assay in hair was used to document the case of a 24-year-old man found dead after a party. Briefly, after a decontamination step, a 50mg sample of the victim's pubic hair was cut into small pieces (<1mm length), and incubated overnight in 3mL of phosphate buffer pH 5 at room temperature. After a liquid-liquid extraction (dichloromethane/ether), the extract was analyzed using a LC-ES-MS/MS method exhibiting a limit of quantification of 0.5pg/mg for LSD. A LSD concentration of 0.66pg/mg of pubic hair was observed. However, this result remains difficult to interpret owing to the concomitant LSD presence in the victim's post mortem blood and urine, the lack of previously reported LSD concentrations in hair, and the absence of data about LSD incorporation and stability in pubic hair.