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Post Mortem Forensic Toxicology

Post Mortem Forensic Toxicology. Jeffery Hackett MSc PhD CSci CChem MRSC jhackett@unitedchem.com. What is it?.

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Post Mortem Forensic Toxicology

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  1. Post Mortem Forensic Toxicology Jeffery Hackett MSc PhD CSci CChem MRSC jhackett@unitedchem.com sufw2010

  2. What is it? Post-Mortem Forensic Toxicology: determines the absence or presence of drugs and their metabolites, chemicals such as ethanol and other volatile substances, carbon monoxide and other gases, metals, and other toxic chemicals in human fluids and tissues, and evaluates their role as a determinant or contributory factor in the cause and manner of death sufw2010

  3. Where do I find out about it? Journals: Forensic Science International J.Forensic Science J. Anal. Toxicology J.Chromatogr. B (and A) Books: R.C. Baselt: Disposition of Toxic Drugs and Chemicals in Man Clarke’s Analysis of Drugs and Poisons J.Garriot: Medico-legal Aspects of Alcohol sufw2010

  4. Interesting cases • Dr. Crippen: Hyocine • Georgi Markov: Ricin • Justin Devilliers: Fentanyl • Ivan Litvanenko: Polonium • Mrs Cahill: Cyanide • Stacy Castor: Ethylene Glycol sufw2010

  5. What’s it all really about 1. How drugs get into people 2. How we get the drugs out 3. How drugs are tested for 4. What does it all mean?? sufw2010

  6. 1. How do drugs get into people?? Intoxicants: Ethanol (Other Alcohols) Oral administration Butane (Other gases) Toluene(also Solvents) Via Inhalation Marilyn Monroe? sufw2010

  7. Illicit Drugs: Cannabinoids: Smoked Amphetamines:Oral Cocaine/ Heroin :Smoked, Snorted, Injected sufw2010

  8. Prescription Drugs: Acetaminophen Propoxyphene Fentanyl Oxycodone Zolpidem Temazepam Methadone Mainly oral administration, some have been abused in other ways sufw2010

  9. Weird and Wonderful Mephedrone MCat Spice (JWH-018) Salvia Divinorum sufw2010

  10. Route of Drugs:Oral administration A.D.M.E. Drugs will leave from the stomach Pass through the Liver Enter into Blood stream/ CSF Leave through Liver/Kidneys Pass into Urine sufw2010

  11. What does this mean for sampling? Bloodis always important (Site?) Liverwill sequester higher levels of drugs Lungs are excellent for solvents Urine is the last point for drugs Hair has problems all of its own Vitreous Humor: Alcohol Data Brain??: Oral Fluid sufw2010

  12. THC in Blood (LC-MSMS)1 ng per mL sufw2010

  13. 2. Getting the drugs out: Volatile/Semivolatile: Headspace Acid drugs : Solvent extraction + Basic drugs : Solid phase (micro) extraction Metals/Metalloids: Digestion sufw2010

  14. Headspace Analysis: • Samples are warmed to create an atmosphere • Aliquots are taken of the vapour • This is free of contamination/ interferences Low boiling:Propane Medium : Ethanol High : Toluene sufw2010

  15. Solvent extraction: pH Modification Addition of acid/ base COOH COO- + H+ H+ + R-COO- COOH Neutral Species are more soluble in organic solvents sufw2010

  16. Solid phase extraction: Samples are pH modified Filtered through porous sorbents Drugs are collected onto modified surfaces Interferences are washed off Compounds of interest are eluted off **pH= pKa +2** pH=pKa +log [ ionised/unionised] sufw2010

  17. Digestion: Dry digestion Samples are: heated, ignited and ashed Residue is dissolved in dilute acid Good for Copper, Lead, Zinc etc Wet digestion Samples are heated in strong acid solution Solution is reduced in volume, neutralized and diluted Good for volatile metals: Mercury Thallium sufw2010

  18. Drug Testing: Immunoassay: ELISA/EMIT/FPIA/RIA Chromatography: Gas Chromatography (FID, ECD, MS) Liquid Chromatography (PDA, FLD, MS/MS) sufw2010

  19. ELISA Instrumentation sufw2010

  20. Method: *Immunoassays are Presumptive Tests *All operators are competency trained. Calibrators are matrix matched Set at Negative, Cut off and Positive values Good for Blood, Urine and Tissue Wide range of analytes available sufw2010

  21. Analyte Negative Cut-Off Positive Amphetamine 2.816 1.023 0.181 0.992 2.562 Barbiturate 1.609 0.504 0.196 1.266 1.555 Benzodiazepine 2.151 0.413 0.113 2.136 0.155 Cannabinoids 1.238 0.658 0.398 1.326 0.497 Cocaine 1.070 0.739 0.430 1.045 0.114 Methadone 1.240 0.668 0.156 1.426 1.529 Methamphetamine 2.170 0.799 0.310 1.658 2.069 Opiate 1.393 0.331 0.145 1.504 0.104 Oxycodone 1.704 1.266 0.488 1.612 1.039 Phencylcidine 2.195 1.210 0.793 2.237 2.332 ELISA Analysis: sufw2010

  22. Gas-ChromatographyInstrumentation sufw2010

  23. Example of Gas-Chromatography sufw2010

  24. Gas-Chromatography Mass Spectrometry sufw2010

  25. Mass Spectrometry sufw2010

  26. Liquid ChromatographyInstrumentation sufw2010

  27. Example of Liquid Chromatography: (xanthines: Theophylline/ Theobrmine/ Caffeine/ 8-Chlorotheophylline) sufw2010

  28. Different Detectors (LC)UV and Fluorescence sufw2010

  29. LC-MSMS sufw2010

  30. Chromatographic Methods • Use Validated/Peer Reviewed ones • Internal Standards (IS) must match analytes • Best IS are: deuterated (MS) : Substituted Analogues (FID,NPD) : Non-drug materials extraction involves : Volatile Solvents (GC) : Miscible Solvents (LC) sufw2010

  31. Chromatographic Analysis Involves: Calibration curves with known standards and controls Derivitization with recognized modifiers (BSTFA, PFPA) Recognized detection methods (SIM, MRM, PDA) sufw2010

  32. Calibration Curve:THC and Metabolite THC (0.25 to 50 ng/ mL) Carboxy-THC (0.25 to 50 ng/ mL) sufw2010

  33. 4. What does it all mean: Toxicology Report RESULTS: Blood (Iliac): Ethyl Alcohol – Not Detected5 Benzoylecgonine – 0.05 mg/L1,2,4 Sertraline – 0.11 mg/L2,4 Desmethylsertraline – 0.01 mg/L2,4 Quetiapine – 0.50 mg/L Negative for Acetaminophen, Amitriptyline, Barbiturates, Chlordiazepoxide, Citalopram, Clomipramine, Cocaethylene, Cocaine, Desipramine, Diazepam, Doxylamine, Ibuprofen, Imipramine, Meperidine, Methadone, Methamphetamine, N-desmethyltramadol, Norpropoxyphene, Pentazocine, Phenytoin, Procainamide, Procaine, Strychnine, Thioridazine, Tramadol, Trazodone, Trimipramine, Venlafaxine, and Verapamil.2,4 For example use only………Not a real report. sufw2010

  34. Interpretation of Drugs: sufw2010

  35. Psilocybin/ Psilocin Question PB IS PC sufw2010

  36. Interpretation of Alcohol:Clinical Values BAC/g% Effect 0.02 Relaxed 0.05 Tranquil 0.10 Coordination problems 0.20 Intoxication Obvious 0.30 Passing Out 0.40 Comatose 0.50 Death sufw2010

  37. Post Mortem Alcohol:A Point of View Widmark: BAC= 100* A Wt*Wf Back-Extrapolation: *Post Absorptive Period Linear Elimination No Alcohol Consumption **Should not be applied because of the number variables** sufw2010

  38. New Issue (EtG/ EtS) Ethylglucuronide molecule sufw2010

  39. My Thanks: Albert Elian Bob Osiwiecz (Erie Co. Med Examiner Lab) J. Spencer Mike Telepchak sufw2010

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