Title: Post Mortem Forensic Toxicology Jeffery Hackett MSc CSci
1Post Mortem Forensic Toxicology
- Jeffery Hackett
- MSc CSci CChem MRSC
- Center for Forensic Sciences
- Syracuse, NY
2What 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
3Where 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 - Clarkes Analysis of Drugs and Poisons
- J.Garriot Medico-legal Aspects of Alcohol
4Whats 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 mean??
-
51. How do drugs get into people??
- Intoxicants Ethanol (Other Alcohols)
- Oral administration
- Butane (Other gases)
- Toluene(also Solvents)
- Via Inhalation
-
6Illicit Drugs
- Cannabinoids
- Smoked
- Amphetamines
- Oral
- Cocaine/ Heroin
- Smoked, Snorted, Injected
-
7Prescription Drugs
- Acetaminophen
- Propoxyphene
- Fentanyl
- Oxycodone
- Zolpidem
- Temazepam
- Methadone
- Mainly oral administration, some have been abused
in other ways -
-
8Route of DrugsOral 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
9What does this mean for sampling?
- Blood is always important (Site?)
- Liver will sequester higher levels of
drugs - Lungs are excellent for solvents
- Urine is the last point for drugs
- Hair has problems all of its own
- Brain??
102. Getting the drugs out
- Volatile/Semivolatile Headspace
- Acid drugs Solvent extraction
-
- Basic drugs Solid phase (micro) extraction
- Metals/Metalloids Digestion
11Headspace Analysis
- Samples are warmed to create an atmosphere
- Aliquots are taken of the vapour
- This is free of contamination/ interferences
- Low boilingPropane
- Medium Ethanol
- High Toluene
12Solvent extraction
- pH Modification
- Addition of acid/ base
- COOH ??COO- H
- H R-COO-? COOH
- Neutral Species are more soluble in
organic solvents
13Solid 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
- pHpKa log ionised/unionised
14Digestion
- 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
15Drug Testing
- Immunoassay
- ELISA/EMIT/FPIA/RIA
- Chromatography
- Gas Chromatography (FID, ECD, MS)
- Liquid Chromatography (PDA, FLD, MS)
16ELISA Instrumentation
17Method
- 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
18ELISA Analysis
19Gas-ChromatographyInstrumentation
20Example of Gas-Chromatography
21Gas-Chromatography Mass Spectrometry
22Mass Spectrometry
23Liquid ChromatographyInstrumentation
24Example of Liquid Chromatography
25Different Detectors (LC)UV and Fluorescence
26Chromatographic 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)
27Chromatographic Analysis
- Involves
- Calibration curves with known
standards and controls - Derivitization with recognized
modifiers (BSTFA, PFPA) - Recognized detection methods
- (SIM, MRM, PDA)
-
28Calibration Curve
294. 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 Fo
r example use onlyNot a real report.
30 Interpretation of Drugs
31Interpretation of AlcoholClinical 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
32Post Mortem A Point of View
- Widmark
- BAC 100 A
- WtWf
- Back-Extrapolation
- Post Absorptive Period
- Linear Elimination
- No Alcohol Consumption
- Should not be applied because of the number
variables -
33My Thanks
- Dr. K. Corrado
- Staff of Forensic Toxicology Laboratory
- Dr(s). Jumbelic/Stoppacher
- Albert Elian
- Jeanna Marraffa
- J. Spencer