This lecture includes Introduction to Poisons, Different Types of Classification of Poisons, Analysis of Poisons (Volatile, Nonvolatile) (Acidic, Basic, Neutral).

1. Poisons
By: Raghu Khimani

2. Poison???
Any substance harmful to living organism
According to German Swiss Physician Paracelsus
“All substances are poisons, there is none which is not a poison.
The right dose differentiate a poison from a remedy."
Thus, it is a substance (solid, liquid or gas),
introduced or brought into contact with any body part, will
produce ill-health or death.

3. Did You Know ?
92% of all poisonings happen at home.
The household products implicated in most
poisonings are: cleaning solutions, fuels, medicines,
and other materials such as glue and cosmetics.
Certain animals secrete a xenobiotic poison called
venom, usually injected with a bite or a sting, and
others animals harbor infectious bacteria.
Some household plants are poisonous to humans and
animals.

4. Law Relating to Poisons
Sections 284, 299, 304A, 324 and 328 of I.P.C. deal with
offence relating to administration of poisonous substances.
Intention is an important element in any act.
So accurate definition of poison in law is not necessary, for
administration of any substance with the intention of
causing injury or death and which causes injury or death, is
legally sufficient for awarding punishment, whether the
substance is one which can be called poison or not.
The law does not make any difference between
murder by means of poison and murder by other means.

5. Classification
ON THE BASIS OF MODE OF
ACTION OF POISON

6. Poisons
Corrosive SystemicIrritant
Strong acid
HCl, nitric
acid, acetic
acid,
hydrocyanic
acid etc.
Strong base
Sodium
hydroxide,
sodium
carbonate
etc.
Inorganic Organic Mechanical
diamond dust,
dry sponge,
glass dust etc.
Vegetable
Kaner,
dhatura
etc.
Animal
Snake venom,
cantharides etc.
Metallic
Hg, As, Pb,
Cu etc.
Non Metallic
Chloride,
cyanide,
phosphate etc.

7. Cardial
Digitalis,
Nicotine
CNS stimulants
Cocaine,
nicotine,
imipramine
Systemic Poison
Spinal
Nux-
vomica
Cerebral Asphyxiants
Carbon dioxide,
war gases
Peripheral
Curare,
Conium
CNS depressants
Barbiturates,
Tranquillizers,
Anesthetic,
Inebriants,
Opiates
Deliriants
Cannabis,
Atropa
Hallucinogens
LSD,
Mescaline
Natural
Opium
Semi synthetic
Heroin
Synthetic
Pethidine

8. Classification
ON THE BASIS OF THEIR CHEMICAL
PROPERTIES AND METHOD OF
ISOLATION FROM TISSUES AND OTHER
BIOLOGICAL FLUIDS

9. Poison
Non-
Volatile
All drugs
like:
Sleeping
pills
Pain killers
Anti-
depressants
Pesticides
DDT,
Eldrin
Malathion
MiscellaneousVolatile
Alcohol
Chloroform
Ether
Acetone
Nicotine
Pyridine
Toxic
Anions
Cyanide,
Phosphate
Clorate
Chloride
Toxic
Cations
Mercury
Arsenic
Lead
Zinc
Animal
Snake
Venom,
Insect bite
Vegetable
Dhatura,
Cannabis,
Kuchila
Food
Poisoning
Due to Micro
organism

10. The Dose Makes the Poison
An apparently nontoxic chemical
can be toxic at high doses. (Too
much of a good thing can be
bad).
Highly toxic chemicals can be life
saving when given in appropriate
doses. (Poisons are not harmful
at a sufficiently low dose).

11. Extraction of Poisons
 An acid is any substance that releases hydrogen ions (H+) when
dissolved in water. A base is any substance that accepts hydrogen ions
(H+) when dissolved in water. Most drugs and poisons are either acids
or bases. For example, most barbiturates have a pH below 7;
therefore, they are acidic. Most amphetamines have a pH above 7
and, therefore, are basic.
 During an acid-base extraction procedure, body fluids, tissues, or
organs are placed in an acidic solution and/or a basic solution. Acidic
drugs or poisons are easily extracted from an acidic solution; basic
drugs or poisons are easily extracted from a basic solution.
 After these acid-base procedures are completed, the drug or poison is
identified as an isolated sample. The isolated sample(s) then goes
through a screening test and, finally, through a confirmation test.

13. Isolation of Poisons

14. Analysis of Poisons
 Toxicological analysis of biological tissues
involves,
 Separation of drug from the biological tissues.
 Purification.
 Analytical detection.
 This is done by any of the analytical techniques
like TLC, HPTLC, IR, Raman, FTIR, FT, FT Raman,
LC, LCMS, GC, GCMS, HPLC, GC MS/MS, AAS, AES,
AES, SEM, TEM, PCR, UV Spectrophotometry,
ICPMS, EXDRF.

15. 1. Gases: Gases are separated from samples by
simple aeration procedure.
2. Volatile Poisons: They include both organic &
inorganic substances & are separated by steam
distillation. Ex. C2H5OH, Amphetamines, etc.
3. Metallic Poisons: By dry washing method &
wet digestion procedure.
4. Non-volatile organic poisons: This includes
poisons which are extracted by CHCL3 or ether.
5. Miscellaneous: This includes all the
substances which are not classified in any of
the above 4 groups. Ex. Glass powder,
Diamond dust.

16. Analysis of Gaseous & Volatile Poisons
1. Alcohol:
 The term alcohol generally means ethyl alcohol.
 Absolute alcohol = 99.95% alcohol
 Rectified Spirit = 90% alcohol
 Industrial methylated spirit = 95% OH + 5% wood naphtha
 Vodka = 60-65% OH
 Rum = 50-60% OH
 Jin, Brandy = 40-45% OH
 Wine = 10-15% OH
 Beer = 4-8% OH
 Alcohol requires no digestion prior to absorption.

17.  Properties:
 Colorless, Volatile, burns with blue flame, used as solvent, B.P.
78° C
 Fatal Dose: 150-250 ml of absolute alcohol consumed in
one hour.
 Fatal Period: 12-24 hours.
 Vitreous humor (eye fluid) and spinal fluids are very
good sample for –OH poison cases.
 Do not use spirit for cleaning the skin before obtaining
blood sample.
 Cases: Accident, house hold, criminal cases.
 Effects: CNS, Eyes, Kidney, Liver, Lungs.

18. 2. CH3OH:
 Pure MeOH is called wood alcohol.
 It is present in certain home-made beverages (tea,
coffee, cold drinks), dyes, resins, adhesives, varnish.
 Toxicity of MeOH can result following its absorption
through skin or respiratory track they consist of nausea
pain or severe cramps in abdomen, headache,
dizziness.
 Fatal Dose: 60-200 ml
 Fatal Period: 24-36 hours.
 P.M. – Cyanosis is marked & there is an absence of PM
clotting of blood.

19. 3. Chloroform – CHCL3:
 Properties: Heavy, clear, colorless, liquid, volatile, strong
smell, insoluble in H2O, B.P. 61° C
 Absorbed by inhalation.
 Between 20- 70%, it is general anaesthetic.
 Symptoms: When swallowed, there is burning pain in
mouth, throat & stomach, within 10 min unconsciousness,
with which slow breathing occurs.
 F.D. = 30 ml
 PM = Characteristic smell is observed in cavity of lungs
and brains.
 Circumstances: Accidental death occurs due to
anesthesia.

20. 4. Acetaldehyde:
 Source: By product in alcoholic fermentation.
 Properties: Colorless, inflammable liquid, B.P. 20.2° C,
miscible in water, ethanol and ether.
 Metabolize through oxidation to acid and then to CO
and water.
 More toxic than C2H5OH & CH3COOH.
5. Acetone:
 Source: A product of destructive distillation of wood.
 Properties: Volatile, inflammable, miscible with water,
C2H5OH, CHCl3, ether, B.P. = 56° C, colorless.
 Generally used in sniffing, glues, whiteners, nail polish
remover, etc.

21. 6. CCl4:
 Properties: Heavy, clear, colorless, liquid having CHCl3
like odor, volatile, almost insoluble in water, miscible
with CHCl3 & ether.
 Absorbed through skin & by inhalation, extracted mostly
from lungs as such.
 It is nephrotoxic.
7. Phenol:
 Properties: Pink, turns dark pink on storage, B.P. = 181° C
 It denatures and precipitates cellular proteins which may
rapidly cause poisoning.
 Rapidly absorb through gastro-intestinal track and/or
penetrates through the skin.

22. 8. Ether:
 Signs: When inhaled, effects are generally similar to
CHCl3 but there is more burning pain in respiratory
track.
 F.D. = 30 ml.
 PM = Brain is edematous, trachea contains frothy
mucus.
 Inebriant poison produce intoxications.
 Ex. Confusion, Drowsiness, - barbiturates, alcohol &
pesticides.

23. Analysis of Volatile Poisons by UV

24. Analysis of Volatile Poisons by Color Tests
Sr. No. Reagent Observation Probable Poisons
1 Addition of bromine
water
Decoloration Aniline, Phenol,
Cresol
2 Addition of AgNO3 Grey / Black ppt. Cyanides,
Phosphorous,
Phosphine.
3 Direct Schiff’s
Reagent
Pink color Acetaldehyde,
Formaldehyde
4 Schiff’s Reagent
added after
Oxidation
Pink color Ethanol, Methanol,
Acetaldehyde,
Formaldehyde.
5 Direct addition of
Deniges Reagent
+Heat
Yellow ppt. Acetone

25. Analysis of Volatile Poisons by Color Tests
Sr.
No.
Reagent Observation Probable
Poisons
6 Aniline + Alcoholic
NaOH + Heat
Obnoxious smell Chloroform,
Chloral
hydrate, Carbon
tetrachloride.
7 Prussian Blue Test Blue ppt or
coloration
Cyanide.

26. Analysis of Acidic Poison (Volatile)
A. Extraction:
1. Steam Distillation:
 Procedure: -
 50 – 100 gm of totally minced viscera.
 Stomach contents are to be taken into the round
bottom flask and add 3-5 times of distilled 𝐻2 𝑂.
 Than acidified with tartaric acid or 𝐻2 𝑆𝑂4 & submit
it to steam distillation.
 A few pieces of pumice stone may be taken in the
flask to prevent bumping.
 It is better to collect the distillate in 4-5 fractions of
which one should not exceed 20 ml.

27. B. Preliminary test:
1. By U.V:
 𝜆 𝑚𝑎𝑥 values of some commonly known
volatile are given below:
Name of Poison 𝝀 𝒎𝒂𝒙 − nm
Aniline 280 nm
Phenol 264 nm
Nitrobenzene 274 nm
Benzene 238 nm

28. 2. Color test of Some Commonly Known Poison:
Test Observation Probable Poison
Aniline + 𝑁𝑎𝑂𝐻
+ ∆
Obnoxious
Smell
𝐶𝐻𝐶𝑙3, 𝐶𝐶𝑙4
Schiff’s reagent Pink Color 𝐶𝐻3 𝐶𝐻𝑂, 𝐻𝐶𝐻𝑂
Direct addition
of Deniges
Reagent + ∆
Yellow PPt 𝐶𝐻3 𝐶𝑂𝐶𝐻3

29. C. Confirmatory Tests:
Ex.1 - 𝑪𝑯 𝟑 𝑪𝑶𝑪𝑯 𝟑:
1. Iodoform Test:
 In 1 ml of distillate, add 2 drops of 1% NaOH.
 This is followed by drop wise addition of 𝐼2 till the solution becomes
brown.
 The solution is allowed to warm in low flame.
 The ppt observed under the microscope, crystals are often found
standing, characteristic Hexagonal crystal of iodoform is seen.
2. Legal’s Test:
 In 1 ml distillate add a few drops of KOH and add 2-3 drops of
saturated solution of freshly prepared Sodium nitroprusside.
 First red color is produced, then Yellow color occurs, then add few
drops of glacial acetic acid are trickled down the side of the test tube
so at the line of junction of the two fluids is formed a
carmine or purple ring.

30. Ex.2 - 𝑪𝑯 𝟑 𝑪𝑯 𝟐 𝑶𝑯:
1. Iodoform Test:
 CH3CH2OH + 𝐼2 + 𝑁𝑎𝑂𝐻 + 𝑣𝑒 𝑅𝐸𝑆𝑈𝐿𝑇
2. Sulfomolybdic acid Test:
 In 2 ml of distillate known reagent is
added.
 Reagent – 1 gm of molybdic acid in 25ml of
conc. 𝐻2 𝑆𝑂4.
 If a deep blue ring appearance at the
junction of the 2 liquids is found – Ethanol
present.

31. D. Analysis by GC:
 System :
 Column = SE30 (2m X 4mm) I.D. glass column.
 Column temp. = 100℃ - 300℃
 Carrier gas = 𝑁2 at 45ml per min.
 The retention index and retention time of some
common poisons are given below:

32. Analysis of Acidic Drugs / Poisons (Non- Volatile)
Ex. - Barbiturates
 They are drugs which are associated with criminal case
poisoning. (Homicidal & Suicidal)
Analysis of Barbiturates:
 Extraction:
 The viscera material about 50-100gm is cut into small pieces.
 Mix with 100ml of 𝐶𝐻3 𝐶𝑂𝑂𝐻 and add solid (𝑁𝐻4)2 𝑆𝑂4.
 The mixture is then heated in water bath.
 It is cooled and filtered; the filtrates were taken in
separating funnel.
 Add 100ml of 𝐶2 𝐻5 − 𝑂 −𝐶2 𝐻5 into it. Shake it & than take
ether layer.
 The acidic extract is tested for barbiturates, salicylate etc.

33. Test for Barbiturates:
1. Dille – Koppayani Test:
 A small amount of extract material is placed in
spot plate.
 3-4 drops of acetate solution and iso-propyl amine
solution are added.
 Purple or blue violet color indicates presence of
barbiturates.
2. By U.V:
Compound 𝝀 𝒎𝒂𝒙
Phenobarbitone 230nm
Allobarbitol 241nm

34. 3. By IR:
4. By GC:
 Column = 𝑆𝐸30
 Carrier Gas = 𝑁2 1 𝑚𝑙/𝑚𝑖𝑛
 Column T. = 100℃ - 260℃.
Compound Principle Peak (Wave No. cm-1)
Phenobarbitone 1310, 1300 cm-1
Allobarbitol 841, 925 cm-1
Barbital 875, 1320 cm-1

35. Analysis of Basic Drugs / Poisons
Basic Drugs: Drugs which are alkaline in nature are called
“Basic Drugs”.
 Mainly contains N, S and O in the ring.
 Narcotics, Cardial Poison
Analysis of Basic Drugs:
 Extraction:
 The aqueous solution remaining in the funnel after the separation of
acidic drugs is made alkaline by addition of 𝑁𝐻4 𝑂𝐻 & 100ml
𝑪𝑯𝑪𝒍 𝟑:Ether (1:3) solution.
 The aqueous solution layer is retained for opium alkaloid.
 Take 50ml of 𝐶𝐻𝐶𝑙3–Ether mixture and add to it.
 This is done for 3 times.
 The extract which is best is taken for alkaloids & other basic drugs
like opium.

36. 1. Color Test:
Reagent Color Observed Compound
CH3CHO, H2SO4 Red or Pink Benzodiazepines
Conc. HNO3 Bright Orange Opium Alkaloid
FPN Reagent Violet red Phenothiazine
FPN Reagent: FeCL4 + Perchloric Acid + Nitric
Acid

37. 2. TLC Test:
 Solvent system = MeOH:𝑁𝐻3 – 100:1.5
 Plate = Silica Gel
 Reagent Spray = FPN Reagent
 Spot Color = No (Colorless)
3. By U.V.:
Compound 𝝀 𝒎𝒂𝒙
Morphine 242 nm
Codeine 236 nm
Diazepam 280 nm
Imipramine 253 nm

38. 4. By I.R.
 Column = Silica Spherisorb.
 Eluent = A solution 0.01 M NH4 perchloride in
100ml CH3OH
Compound K1 Value
Amphetamine 0.9
Benzphetamine 1.2
Ephedrine 1.0
Mescaline 1.3

39. 5. By G.C.:
 Column1 = 2.5% of dimethyl dichloro silicon
treated.
 Column 2 = SE30
 Column T. = 100℃ - 300℃
 Carrier Gas = N2

40. Analysis of Neutral Poisons
1. Organo Phosphorus:
 This is considered as the derivatives of corresponding
acid or H-Phosphide
 Ex. Dichlorovos, Parathion, Thiamet, etc.
 Compounds of Forensic Interest:
 Dichlorovos, Parathion, Fenthion.

41.  Analysis:
1. By TLC:
 Solvent system: n-Hexane : Acetone (8:2)
 Plate: Silica
 Spray Reagent: Mercurous Nitrate.
 Color of Spot: Black
2. By GC:
 Column: OV 17
 Column Temp.: 100-300° C
 Carrier Gas: H2, N2 & Air

42. 2. Organo Chloro:
 These are extensively used in agriculture and domestic
application.
 Ex.: DDT, BHC, Anarine, Lindane.
A. Extraction:
 The sample is taken in a conical flask.
 50ml of n-hexane is added to it.
 It is refluxed on water bath for half an hour.
 After cooling, the liquid is filtered and evaporated to dryness.
Use it for analysis.

43. B. By TLC:
 Plate: Silver
 Solvent SVS: Hexane: Acetone (9:1)
 Spray Reagent: Zinc chloride diphenyl
 Color of spot: Bluish Green
C. Color test of DDT:
 5 ml of chloro benzene is added to the extract + warm
it & filter through AlCl3.
D. By GC:
 Column: SE30
 Column Temp.: 190° C
 Carrier Gas: N2 at 95ml/min.

44. 3. Carbamates:
 Ex.: Zinab, Carbarin, Carbafuran.
A. By GC:
 Column: DB
 Carrier Gas: He2 at 10ml/min
 Column Temp: 50-250°C
4. Fungicides:
 Potassium Sulphide, Captan, Dithianon.