Classical Extraction (STAS-Otto, Ammonium Sulphate, Distillation, Microdiffusion): Application (UGC-NET Unit IV)
Published:
Questions
30
Duration
30 min
Faculty-reviewed
0
Updated
17 May 2026
About this mock
UGC-NET Forensic Science Unit IV drill on classical extraction, isolation and clean-up of poisons at the application band. Scenarios cover the Stas-Otto (1851 and 1856) general-unknown workflow on viscera with sequential pH-controlled liquid-liquid partition into acid-neutral, basic, alkaloid and conjugate fractions, ammonium sulphate salting-out for protein-bound drugs, steam and simple distillation for volatiles (methanol, ethanol, phenols, ammonia), Conway microdiffusion (1947) for cyanide, formaldehyde, sulfide and other small volatiles in small-volume blood and viscera, Fresenius-Babo dry destruction and HNO3-H2SO4-HClO4 wet ashing for metallic poisons in the toxicology section, Reinsch screening, and Visking dialysis for separating small molecules from protein matrices. Indian context covers CFSL Hyderabad's classical screening tier ahead of HPLC and LC-MS confirmation.
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 15 questions
Moffat A C, Osselton M D, Widdop B (eds), Clarke's Analysis of Drugs and Poisons, Pharmaceutical Press
Ammonium sulphate plasma fractionation; 50 percent saturation cut for globulins
Open source - cited in 6 questions
Conway E J, Microdiffusion Analysis and Volumetric Error, Crosby Lockwood and Son, London (1947)
Cyanide microdiffusion from acidified blood; Konig pyridine-pyrazolone read-out
Open source - cited in 6 questions
Modi N J, Modi's Medical Jurisprudence and Toxicology, LexisNexis
Fresenius-Babo dry destruction for arsenic and mercury in viscera; sodium carbonate plus potassium nitrate fusion
Open source - cited in 1 question
Cavett J W, A rapid method for the determination of ethyl alcohol in body fluids, Journal of Laboratory and Clinical Medicine 24:543-545 (1938)
Cavett microdiffusion method for blood alcohol; cited in Clarke's Analysis of Drugs and Poisons
Open source - cited in 1 question
Bureau of Police Research and Development (BPR&D), CFSL Toxicology Section SOP Manual
Classical screening tier in CFSL Hyderabad toxicology workflow; tiered approach to general-unknown viscera cases
Open source - cited in 1 question
Stas J S, Recherches médico-légales sur la nicotine, Bulletins de l'Académie royale de Belgique 18:304-359 (1851); reproduced in Clarke's Analysis of Drugs and Poisons
Original Stas procedure for isolation of nicotine from viscera; acidified ethanol primary solvent
Open source
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 Classical Extraction (STAS-Otto, Ammonium Sulphate, Distillation, Microdiffusion): Application (UGC-NET Unit IV) mock cover?+
UGC-NET Forensic Science Unit IV drill on classical extraction, isolation and clean-up of poisons at the application band. Scenarios cover the Stas-Otto (1851 and 1856) general-unknown workflow on viscera with sequential pH-controlled liquid-liquid partition into acid-neutral, basic, alkaloid and conjugate fractions, ammonium sulphate salting-out for protein-bound drugs, steam and simple distillation for volatiles (methanol, ethanol, phenols, ammonia), Conway microdiffusion (1947) for cyanide, f
How many questions and how long is the test?+
30 multiple-choice questions, 30 minutes total. Difficulty: medium. Tier: Premium.
Who is this mock for?+
Forensic science students and aspirants who want timed, exam-style practice with explanations and verified source citations on NET. Useful for postgraduate entrance preparation and for BSc / MSc forensic students testing their recall under time.
Are the questions reviewed?+
Each question carries a verified source citation. Faculty review for individual questions is in progress.
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.