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Clinical Analytics: Toxicological Screening/ Screening for Drugs of Abuse. Martin Slusarczyk & Dino Wu 9th of Oct 2012. Quick overview. What are legal highs ? Mechanism of the action of neurotransmitters Overview of psychoactive substances and drug classes
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Clinical Analytics: Toxicological Screening/ Screening for Drugs of Abuse Martin Slusarczyk & Dino Wu 9th of Oct 2012
Quick overview • Whatare legal highs? • Mechanismoftheactionofneurotransmitters • Overviewofpsychoactivesubstancesanddrugclasses • Analytical strategyforourcase
What are Legal Highs? • Psychoactive chemicals • In general: Possession and marketing are „legal“ (for the most part not anymore) • Origins: Synthetic or natural • Control problem, as little is known about these compounds.
General Effects of Legal Highs to the Neurotransmission • Similar structureto endogenous neurotransmitters • Agonist: Reductionofneurotransmitter reuptake • Antagonist: Interfering neurotransmitter synthesis or blocking of the postsynapticreceptors • Many possible consequences like: - Hallucinations- Paranoia- Euphoria- Panic Attacks- Anxiety
„Legal High“ Situation in Switzerland • BetmKV art. 8 p. 1: Following narcotics cannot be cultivated, imported, produced or put into circulation: • - Opium or the remains after the production or consumation- Diacetylmorphine or its salts- Hallucinogens like lysergide (LSD-25)- Narcotics with Cannabis-like effects.
„Legal High“ Situation in Switzerland • Since May 2011, a register for narcotics legal ordinance has been written with detailled informations about which compounds are controlled (like derivatives, salts)
Considerationsfortheanalysis • Priorityisthehealthofthepatient -> Fast and quantitative
What are we looking for? • The actualpsychoactivesubstances, drugs • Neglect extenders (Streckmittel), colourants.. • Askpatientwhether he tookdrugsandwhen. • Askformedicine he istaking (Perturbations?)
Hair (onlyforlongtermanalysis) Sweat Nose -> cottonbuds (solid particles) Blood (dissolved) Sample ofchoice (due to high concentrations): Urine (dissolved) Whichsamples?
Urine • Expected range: 10-1000 ng/ml (dependent on the compound) • Check of identity • One sample suffices, if additional blood samples are taken
Quantification: Whichmethod ? • Atomicabsorption: forelements • Electrophoresis: CZE-DAD used, but lowsensitivity: enrichmentneeded • GC: volatile? Often derivatization neededGC-MS has the advantage to have a large reference library
Confirmatorytest: LC-ESI-MS/MS • „Sensitive analysisofcompoundswith a widepolarityrange in samplesofvariousnature“ • Limits ofquantitation (LOQ): 1–100 ng/mL • Calibration: 10–10 000 ng/mL External calibration: Urine (healthy volunteer) Deuterated analogs (e.g. metabolites, opiates etc.) as internal standards -> recovery rate
Sample preparation • Addition ofbuffers • Vortexing • LLE or SPE (Liquid liquid extraction or solid phase extraction) • Injection of 10 μl of the prepared urine into LC
Blood - LC-ESI-MS/MS • Comparison to LC-EI-GC: • Fasterasnoderivatizationisneeded • Lessspecificfragmentsandfewerspectraofdatabanks • Normally expected range: 10-500 ng/ ml • Calibration: 1–1000 ng/mL (also lower conc.) Blood (healthyvolunteer) -> externalcalib. Deuterated analogs (e.g. metabolites, opiates etc.) asinternalstandards -> recovery rate
Matrix interferants: • Proteins ( ~ 10 000 Da) • Antibodies (~ 100 000 Da) • Clottingfactors (~ 50 – 300 000 Da) • Wide range of lipophilic substances (disturb ionization process)
Sample preparation • Addition ofbuffers • Add a dropofAcNto sample, thencentrifugation (cells, proteins) • Injectioninto LC
Interpretation anderrorsources • Analysis by skilled professionals • Time passedsincedrugintake • Matrix interferences