Rapid analysis of Δ-9-tetrahydrocannabinol in hair using direct analysis in real time ambient ionization orbitrap mass spectrometry.

RATIONALE: Forensic hair analysis methods are laborious, time-consuming and provide only a rough retrospective estimate of the time of drug intake. Recently, hair imaging methods using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) were reported, but these methods require the application of MALDI matrix and are performed under vacuum. Direct analysis of entire locks of hair without any sample pretreatment and with improved spatial resolution would thus address a need. METHODS: Hair samples were attached to stainless steel mesh screens and scanned in the X-direction using direct analysis in real time (DART) ambient ionization orbitrap MS. The DART gas temperature and the accuracy of the probed hair zone were optimized using Δ-9-tetrahydrocannabinol (THC) as a model compound. Since external contamination is a major issue in forensic hair analysis, sub-samples were measured before and after dichloromethane decontamination. RESULTS: The relative intensity of the THC signal in spiked blank hair versus that of quinine as the internal standard showed good reproducibility (26% RSD) and linearity of the method (R(2) = 0.991). With the DART hair scan THC could be detected in hair samples from different chronic cannabis users. The presence of THC was confirmed by quantitative liquid chromatography/tandem mass spectrometry. Zones with different THC content could be clearly distinguished, indicating that the method might be used for retrospective timeline assessments. Detection of THC in decontaminated drug user hair showed that the DART hair scan not only probes THC on the surface of hair, but penetrates deeply enough to measure incorporated THC. CONCLUSIONS: A new approach in forensic hair analysis has been developed by probing complete locks of hair using DART-MS. Longitudinal scanning enables detection of incorporated compounds and can be used as pre-screening for THC without sample preparation. The method could also be adjusted for the analysis of other drugs of abuse.

Saccadic peak velocity and EEG as end-points for a serotonergic challenge test.

UNLABELLED: We previously reported that a single dose of the serotonin receptor agonist meta-chlorophenylpiperazine increased the peak velocity of saccadic eye movements and decreased low-frequency electroencephalographic activity. METHODS: We administered a single dose of the serotonin releaser dexfenfluramine in a double blind, placebo controlled randomised cross-over design and measured saccadic eye movements and EEG every hour up to 6 h. Subjects were 62 males (18-30 years) with a history of no, moderate or heavy use of ecstasy tablets. RESULTS: Dexfenfluramine increased saccadic peak velocity and decreased alpha, delta and theta electroencephalographic activity, the latter predominantly in heavy users of ecstasy. CONCLUSIONS: This study supports the idea that saccadic peak velocity and EEG can be useful endpoints of a serotonergic challenge. This could be an important anatomical extension of these end-points, which until now were limited to the effect on hypothalamic serotonergic projections.

Effects of concurrent use of alcohol and cocaine.

The combination of alcohol and cocaine is popular among drug users, perhaps because of more intense feelings of 'high' beyond that perceived with either drug alone, less intense feelings of alcohol-induced inebriation and tempering of discomfort when coming down from a cocaine 'high'. A review is presented of the medical literature on psychological and somatic effects and consequences of combined use of alcohol and cocaine in man. The search was carried out with Medline, the Science Citation Index/Web of Science and Toxline. Exclusion and inclusion criteria for this search are identified. There is generally no evidence that the combination of the two drugs does more than enhance additively the already strong tendency of each drug to induce a variety of physical and psychological disorders. A few exceptions must be noted. Cocaine consistently antagonizes the learning deficits, psychomotor performance deficits and driving deficits induced by alcohol. The combination of alcohol and cocaine tends to have greater-than-additive effects on heart rate, concomitant with up to 30% increased blood cocaine levels. Both prospective and retrospective data further reveal that co-use leads to the formation of cocaethylene, which may potentiate the cardiotoxic effects of cocaine or alcohol alone. More importantly, retrospective data suggest that the combination can potentiate the tendency towards violent thoughts and threats, which may lead to an increase of violent behaviours.