Forensic Toxicology: Sample Collection and Preservation
Published:
Questions
30
Duration
30 min
Faculty-reviewed
30
Updated
03 May 2026
About this mock
This mock covers the practical sample-collection and preservation layer of forensic toxicology — the part of the syllabus that decides whether the laboratory result will hold up in court at all. Thirty questions on what to collect, when, into which tube, with which preservative, why, and how to keep the chain of custody intact, at the depth expected of a first-year MSc Forensic Science student or a FACT / UGC-NET aspirant. The matrices section moves from antemortem (whole blood, serum, plasma for DUI; urine for workplace screens; oral fluid for roadside recent-use; hair for longitudinal exposure) through the full postmortem suite (femoral blood preferred over central, vitreous humour for ethanol confirmation and postmortem-interval estimation by potassium, gastric contents for evidence of oral ingestion, liver as a basic-drug reservoir, bile for opiate glucuronides, brain for inhalants and lipophilic CNS drugs, bone marrow and nail in skeletal cases). A dedicated cluster covers postmortem redistribution (PMR) — the central:peripheral ratio concept, why femoral blood is the gold-standard postmortem specimen, and the drugs (TCAs, digoxin, fentanyl, lipophilic basic drugs) most notorious for PMR.
It is pitched at BSc and first-year MSc forensic science students at NFSU, LNJN-NICFS, and other Indian universities, and at FACT, FACT Plus, and UGC-NET aspirants who need the sample-handling fundamentals locked in before tackling the analytical-chemistry papers. Sample collection is one of the highest-yield exam topics in Indian forensic-toxicology papers because every mistake here invalidates everything downstream.
Topics covered:
- Antemortem matrices — whole blood, serum, plasma for DUI; urine for workplace screens; oral fluid for recent use; hair for longitudinal exposure
- Postmortem matrices — femoral blood, vitreous humour, gastric contents, liver, bile, urine, brain, bone marrow / nail in skeletal cases
- Postmortem redistribution — central:peripheral ratios, drugs notorious for PMR, why femoral blood is preferred
- Preservatives — sodium fluoride 1% w/v (anti-glycolysis, anti-microbial), potassium oxalate (anticoagulant), EDTA for haematology and DNA
- Storage temperatures — 4 °C short-term, -20 °C archival, -70 °C for labile compounds
- Containers — glass with butyl-rubber septa for volatiles, headspace minimisation, light-protected amber glass for photolabile drugs
- Chain of custody, tamper-evident seals, labelling, transport in cool boxes
- Special scenarios — alcohol-case cross-checks (vitreous, n-propanol, EtG/EtS), CO with COHb on sealed blood, cyanide with urgent or frozen analysis, inhalant-abuse on sealed glass
Each question carries a detailed 220+ word explanation citing standard references — Modi's Textbook of Medical Jurisprudence and Toxicology (26th ed.), Karch & Drummer's Pathology of Drug Abuse (5th ed., CRC 2015), Levine's Principles of Forensic Toxicology (5th ed., AACC 2020), Cooper & Negrusz's Clarke's Analytical Forensic Toxicology (2nd ed.), the SOFT/AAFS Forensic Toxicology Laboratory Guidelines, the Society of Hair Testing consensus, SWGTOX standard practices, NAME forensic-autopsy standards, the EU DRUID project, SAMHSA workplace-drug-testing guidelines, Garriott's Medicolegal Aspects of Alcohol, Madea's Estimation of the Time Since Death, and the foundational Pounder & Jones 1990 paper on postmortem redistribution. Allow 30 minutes; the explanations are long enough to use as study notes by themselves.
Sources & references
Questions in this mock are written and verified against the following sources. Citations are recorded per question and shown in the explanation after submission.
- cited in 5 questions
Cooper, G. & Negrusz, A. (eds.) — Clarke's Analytical Forensic Toxicology
2nd Edition, Chapter on Stability — photolabile analytes and protective packaging
- cited in 4 questions
Levine, B. (ed.) — Principles of Forensic Toxicology
5th Edition, Chapter on Inhalants and Volatile Substances — specimen handling
- cited in 3 questions
Karch, S.B. & Drummer, O.H. — Karch's Pathology of Drug Abuse
5th Edition (CRC Press, 2015), Chapter on Postmortem Toxicology and Postmortem Redistribution
- cited in 2 questions
SOFT/AAFS — Forensic Toxicology Laboratory Guidelines
Section on Specimen Storage Temperatures and Archival
Open source - cited in 2 questions
Garriott, J.C. (ed.) — Garriott's Medicolegal Aspects of Alcohol
6th Edition, Chapter on Specimen Collection and Preservation — sodium fluoride at 1% w/v
- cited in 1 question
Modi, J.P. — A Textbook of Medical Jurisprudence and Toxicology
26th Edition, Chapter on Asphyxiant Poisons — carbon monoxide and COHb measurement
- cited in 1 question
SWGTOX — Standard Practices for the Collection and Handling of Forensic Toxicology Specimens
Section on Specimen Transport and Receipt
Open source - cited in 1 question
Kintz, P. (ed.) — Analytical and Practical Aspects of Drug Testing in Hair
Chapter on Alternative Keratinised Matrices — nail and bone marrow in decomposed remains
- cited in 1 question
SOFT — Society of Forensic Toxicologists Position Statement on Newborn Drug Testing
Section on Meconium and Umbilical Cord as Validated Matrices
Open source - cited in 1 question
Drummer, O.H. & Odell, M. — The Forensic Pharmacology of Drugs of Abuse
Chapter on Postmortem Tissue Concentrations — liver as a reservoir matrix
- cited in 1 question
SWGTOX — Standard Practices for the Collection and Handling of Specimens
Section on Specimen Labelling Requirements
Open source - cited in 1 question
Saukko, P. & Knight, B. — Knight's Forensic Pathology
4th Edition, Chapter on Toxicology at Autopsy — gastric content collection and interpretation
- cited in 1 question
Pounder, D.J. & Jones, G.R. — Postmortem Drug Redistribution: A Toxicological Nightmare
Forensic Science International, 1990, 45(3): 253-263
- cited in 1 question
Society of Hair Testing (SOHT) — Recommendations for Hair Testing in Forensic Cases
Section on Segmentation and Interpretation
Open source - cited in 1 question
DRUID Project (EU) — Driving Under the Influence of Drugs, Alcohol and Medicines
Final Report, Section on Oral Fluid as the Roadside DUID Matrix
Open source - cited in 1 question
SWGTOX (Scientific Working Group for Forensic Toxicology) — Standard Practices
Section on Chain of Custody and Specimen Handling
Open source - cited in 1 question
National Association of Medical Examiners (NAME) — Forensic Autopsy Performance Standards
Section on Routine Toxicology Specimens at Medico-legal Autopsy
Open source - cited in 1 question
SAMHSA — Mandatory Guidelines for Federal Workplace Drug Testing Programs
Section on Specimen Collection and Cut-off Concentrations for Urine
Open source - cited in 1 question
Madea, B. (ed.) — Estimation of the Time Since Death
3rd Edition, Chapter on Vitreous Potassium and Postmortem Interval Estimation
How our mocks are built
Questions are written and edited by the ForensicSpot team and cited from peer-reviewed forensic textbooks, official syllabi and primary case law. Each one is verified before publishing. Detailed explanations show after you submit, so the test stays a real test. See a mistake? Tell us.
Common questions
What does the Forensic Toxicology: Sample Collection and Preservation mock cover?+
This mock covers the practical sample-collection and preservation layer of forensic toxicology — the part of the syllabus that decides whether the laboratory result will hold up in court at all. Thirty questions on what to collect, when, into which tube, with which preservative, why, and how to keep the chain of custody intact, at the depth expected of a first-year MSc Forensic Science student or a FACT / UGC-NET aspirant. The matrices section moves from antemortem (whole blood, serum, plasma fo
How many questions and how long is the test?+
30 multiple-choice questions, 30 minutes total. Difficulty: easy. Tier: Free.
Who is this mock for?+
Forensic science students and aspirants who want timed, exam-style practice with explanations and verified source citations on Forensic Toxicology, FACT, NET. Useful for postgraduate entrance preparation and for BSc / MSc forensic students testing their recall under time.
Are the questions reviewed?+
Yes — 30 of 30 questions are faculty-reviewed. Each question carries a verified source citation.
Do I need an account to take this mock?+
Yes, a free ForensicSpot account is required to start a timed attempt — this lets you save progress, see per-question explanations after submission, and track your topic-level performance over time.