Analytical Toxicology. Methodology of toxicological ...toxicchem.nuph.edu.ua/wp-content/uploads/2020/01/3... · Analytical Forensic Toxicology The task of Analytical Forensic Toxicology

Analytical Toxicology. Methodology of toxicological analysis.

Chemicotoxicological analysis of inorganic acids, alkalis, nitrates

and nitrites

Topic of the lecture:

NATIONAL UNIVERSITY OF PHARMACY

DRUG AND ANALYTICAL TOXICOLOGY DEPARTMENT

DRUG AND ANALITICAL TOXICOLOGY

Lecturer: Karpushyna Svitlana Anatoliivna,

Ass. Prof., PhD in Chemistry

National University of PharmacyDrug and Analytical Toxicology Department

Plan of the lecture

1. Subject and applied aspects of Analytical Toxicology.

2. Methodology of toxicological analysis.

3. Chemicotoxicological analysis of inorganic acids, alkalis, nitrates and nitrites.

3.1. Physicochemical properties and usage of mineral acids, alkalis, nitrates and nitrites.

Toxicity of mineral acids, alkalies, nitrite.

3.2. The general scheme of chemical toxicological examination of biological material for

mineral acids, alkalis, nitrates and nitrites.

3.3. Analysis of the dialyzate for sulphuric, nitric and hydrochloric acids.

3.4. Analysis of the dialyzate for potassium hydroxide, sodium hydroxide and ammonium

hydroxide.

3.5. Analysis of the dialyzate for nitrite and nitrate.


LITERATUREMain

1. Karpushina S.A. Toxicological chemistry. Lecture course / S.A. Karpushina, V.S. Bondar, I.O.

Zhuravel. – Kharkiv: NUPh: Golden pages, 2011. – 208 p.

2. Toxicology: Summary of lectures, practice and tests on toxicology / S.M.Drogovoz, T.O.

Kutsenko, A.Yu. Pozdniakova, V.A. Ulanova. Kharkiv : NUPh : Golden Pages, 2011.– 88 p.

3. Karpushyna, S.A. Workbook for practical lesons on drug and analytical toxicology / S.A.

Karpushyna, S.V. Baiurka. – Kh.: NUPh Publishing, 2019. – 87 p.

4. Karpushina S.A. Toxicological chemistry. Schemes and Tables: Handbook for students of

higher schools / S.A. Karpushina, V.S. Bondar. – Kharkiv : NUPh : Golden Pages, 2009.– 120

p.

Auxiliary

1. Flanagan, R. J. Developing Analytical Toxicology Services: Principles and Guidance [Electronic

resource] / R. J. Flanagan. – Geneva : World Health Organization, 2005. – 36 p. – Available at :

http://www.who.int/ipcs/publications/training_poisons/hospital_analytical_toxicology.pdf (date of

the application : (07.09.2017). – Developing Analytical Toxicology Services: Principles and

Guidance.

2. Clarke's analysis of drugs and poisons in pharmaceuticals, body fluids and postmortem

material: 4-th edition / A. C. Moffat; M.D. Osselton; B. Widdop [et al.]. – London, Chicago:

Pharmaceutical Press, 2011. – 2736 p.

3. Clarke’s Analytical Forensic Toxicology / Ed. by Sue Jickells, Adam Negrusz. – London:

Pharmaceutical Press, 2008. – 648 p.

http://www.who.int/ipcs/publications


Subject and applied aspects of

Analytical Toxicology



Analytical Toxicology definition

Analytical toxicology develops methods of chemicotoxicological

analysis of xenobiotics which are used for their determination in

various samples: namely,

the methods for sample preparation (isolation, purification,

concentration),

detection,

identification,

quantification of xenobiotics

and their metabolites in biological and other samples of the

toxicological study.

Assignments of Analytical Toxicology

Ad

ditio

nal

services

Analytical Toxicology

Analytical Forensic Toxicology (Forensic Chemistry)

(Task: to elucidate the questions that occur in

judicial proceedings)

Clinical Analytical Toxicology(Task: to assist in the treatment of the patients with cases

of acute or chronic poisonings)

Environmental Toxicology

Food Toxicology

Occupational Toxicology(Task: to study the agricultural products, water and air of

industrial ejections, domestic chemicals, etc. for the

presence of toxic substances to maintain the public health

legislation)

Analytical diagnostics of drug abuse

Analytical diagnostics of

acute intoxications

Analytical

diagnostics

abuse in sports

Therapeutic

Drug Monitoring



Analytical Forensic Toxicology

The task of Analytical Forensic Toxicology is determination of the cause of

lethal poisoning by a chemical substance during the forensic examination

Location: Medical Examiner’s Office.

Samples for research: evidence of poisoning, sectional material (stomach

with contents, liver, spleen, kidney, etc.), urine, blood, bile and other

samples.


Clinical Analytical Toxicology

Analytical diagnostics of acute intoxications

The task: to establish the nature of the poisonous substance and recommendations for

methods of detoxification (in cooperation with the physician).

Location: clinical laboratories of toxicological departments, laboratories of centers of clinical

toxicology, Office of Forensic Services.

Samples for research: blood, urine, saliva, sweat allocation, vomit masses, stomach

washings (first portions), liquid peritoneal dialysis and other samples.

Examination of alcohol, narcotic and toxic intoxication

The task: to determine the degree of alcohol intoxication and to establish the fact of the use

of narcotic and psychotropic substances for non-medical purposes.

Location: drug treatment centers

Samples for research: blood, urine, saliva, hair, nails, stomach ulcers and other samples.


Doping control

The task: to determine the use of doping agents

Location: laboratories accredited by the World Anti-Doping Agency (WADA)

Samples for research: biological fluids


Methodology of toxicological analysis


The general stages of any

forensic toxicological examination

No Stage

1 Detection – to detect any drugs or poisons in the samples submitted by

means of screening procedures

2 Identification – to identify conclusively any drugs, metabolites or poisons

present by means of specific relevant physicochemical tests

3 Quantification – to quantify accurately those drugs, metabolites or poisons

present

4 Interpretation – to interpret the analytical findings in (or and) in the context

of the case, the information given and the questions asked by the

investigating officer


The information for the analytical testing scheme design

No Data

1 Information from the accompanying documents (data from preliminary criminal

investigations or in subsequent court proceedings, conclusions of a medical examiner,

pathologist, etc.)

2 Results of external examination (colour, odour, consistance, presence or absence of

suspended solids or sediments, pH)

3 Results of preliminary tests (General Drug screening, preliminary tests for heavy metal

and arsenic compounds, alcohols, volatile poisons, organophosphorus pesticides, etc.)


Guiding principles of forensic

toxicology determined by its legal aspect

No Principle

1 All chemists who undertake this work must have toxicological experience

2 The analyst must be given a complete case history that contains all the

information available

3 All the evidential material, suitably labelled and sealed in clean containers,

must be submitted and examined

4 All the known identification tests should be applied and adequate notes

made at the time

5 All the necessary reagents used for these tests should be pure, and blank

tests should be performed to establish this fact

6 All tests should be repeated, and compared with control samples to which

the indicated poison has been added


Classification of poisons according to

their isolation method from biological material

Substances isolated by

mineralization of the sample

(Metal poisons)

Organophosphorus compounds, chlorinated pesticides,

derivatives of phenol and urine, carbonates, etc.

Substances isolated by extraction

with acidified water or acidified

ethanol (Drugs)

Hydrocyanic acid, acetic acid, halocarbons, alcohols,

aldehydes, phenols and cresols, aniline

Salicylates, barbiturates, pyrazolones, benzodiazepines,

phenothiazines, derivatives of p-aminobenzoic acid,

alkaloids

Barium, lead, manganese, chromium, silver, bismuth,

copper, cadmium, mercury, zinc, arsenic, antimony,

thallium compounds

Mineral acids, alkalies, ammonium, nitrate, nitrite

Fluoride, bromide, iodide

Substances isolated by steam

distillation (Volatile poisons)


with organic solvents (Pesticides)


with water

Substances isolated by special

methods

Substances detected in a

biological sample without

isolation

Carbon monoxide, hydrogen sulphide (in blood)


Physicochemical properties and usage of mineral acids,

alkalis, nitrite and nitrate


PHYSICOCHEMICAL PROPERTIES AND USAGE OF SOME

MINERAL ACIDS, ALKALIS, SALTS

Substance Physicochemical properties Usage

Sulphyric

acid

Transparent, colourless, oily liquid, well

soluble in water with the large exothermic

effect, hygroscopic, with specific pungent

odor and acidic taste

Manufacture of fertilization,

metallic alloys, chemical

reagents, dyes, leather, etc.

Nitric acid

Colourless or rather yellow liquid with

pungent choking odor and acidic taste,

well soluble in water with exothermic

effect, hygroscopic

Manufacture of fertilization,

explosive substances, dyes,

printing, etc.

Hydrochloric

acid

Colourless or rather yellow solution of

hydrochloride with water with acidic taste

and specific pungent odor

Medical practice,

hydrometallurgy,

galvanoplastics, can and textile

manufacturing


PHYSICOCHEMICAL PROPERTIES AND USAGE OF SOME

MINERAL ACIDS, ALKALIS, SALTS

Substance Physicochemical properties Usage

Sodium

hydroxide

White crystalline substance, well soluble

in water, ethanol

Manufacture of artificial textile,

soap, paper, petroleum industry

Potassium

hydroxide

White crystalline substance, well soluble

in water ethanol

Manufacture of soap, potassium

compounds and oxalic acid

Ammonium

hydroxide

Colourless solution of ammonia in water

with pungent odor

Chemical and refrigeration

industry, silvering.

Nitrite

Colourless or rather yellow crystalline

substance with salty taste, hygroscopic,

well soluble in water, moderate oxidizer,

destructing by acids with separation of

nitrogen oxides

Manufacture of dyes; in

medicine as vasodilators,

antidiarrheal and diuretic drugs,

antidote at cyanide poisoning


Toxicity of mineral acids, alkalis, nitrite


ROUTES OF ADMINISTRATION IN A BODY, LETHAL DOSES

AND MECHANISM OF TOXICITY OF SOME MINERAL ACIDS,

ALKALIES, SALTS

Substance Routes of

administration

Lethal dose Mechanism of toxicity

Sulphyric acid Mouth 5–10 g Proton causes an immediate

coagulation-type necrosis

that creates an eschar,

which tends to self-limit

further damage

Nitric acid Mouth, lungs 8–10 g

Hydrochloric

acid

Mouth, lungs 10–15 g


ROUTES OF ADMINISTRATION IN A BODY, LETHAL DOSES AND

MECHANISM OF TOXICITY OF SOME MINERAL ACIDS, ALKALIES,

SALTS

Sodium

hydroxide

Mouth, lungs (as

dust)

5–10 g Hydroxyl causes a liquefactive

necrosis with saponification and

continued penetration into deeper

tissues, resulting in extensive

damage

Potassium

hydroxide

Mouth, lungs (as

dust)

5–10 g

Ammonium

hydroxide

Mouth as solution,

lungs (as vapour)

10 ml of

25% solution

Sodium

nitrite

Mouth 1 g Nitrites are potent oxidizing

agents; oxidation of hemoglobin

may result in

methemoglobinemia, which

hinders oxygen-carrying capacity

and deliver


TOXICITY OF MINERAL ACIDS

Acid burn


TOXICITY OF ALKALIES

Alkali burn


The general scheme of chemical toxicological examination of

biological material for mineral acids, alkalis, nitrite and

nitrate


CHEMICAL TOXICOLOGICAL EXMINATION OF BIOLOGICAL MATERIAL FOR MINERAL

ACIDS, ALKALIES AND NITRITES

Samples: stomach with the contents,

vomit, food; additionally blood, urine

(nitrites, nitrates)

Preliminary examination: determinatin of sample pH ( acids, alkalies, ammonia)

Isolation: extraction by water (all mineral

poisons)

Purification of water extracts from

proteins by dialysis

Alkaline dialyzate (рН = 8– Acidic dialyzate (рН = 1–2)

Detection

Acids – by anion bound with proton

Alkalies – by sodium, potassium or

ammonium cations

Nitrite – by nitrite anion

Distillation of acids ( at the presence of

copper filings for sulpfuric and nitric acids)

Quantitative determination

Nitrite: photocolorimetry by

azodye formation

Acids and alkalies: potentiometry


DETECTION OF SOME MINERAL ACIDS, ALKALIES AND

NITRITES BY CHEMICAL REACTIONS

Substance Chemical reaction

Sulphuric acid Reaction with barium chloride

Reaction with lead acetate

Reaction with sodium rhodisonate and barium salt

Nitric acid Reaction with diphenylamine

Reaction with brucine in concentrated sulphuric acid.

Colouring wool yellow

Hydrochloric acid Reaction with silver nitrate

Reaction with potassium chlorate

Potassium hydroxide Reaction with sodium hydrotartrate

Reaction with sodium cobaltinitrite (Na3[Co(NO2)6])

Sodium hydroxide Reaction with potassium hydroxystibnate (K[Sb(OH)6])

Reaction with uranyl zinc acetate (Zn(UO2)3(CH3COO)8)


DETECTION OF SOME MINERAL ACIDS, ALKALIES AND

NITRITES BY CHEMICAL REACTIONS

Substance Chemical reaction

Ammonia (after

examination of a

biological sample for

hydrogen sulphide with

the reactive paper

moistened by lead acetate)

Reactions with litmus paper and reactive paper moistened by

copper sulphate

Reaction with Nessler’s reagent

Nitrite Reaction with sulphanilic acid and β-naphthol

Reaction with Griss reagent (sulphanilic acid and α-naphthyl

amine)

Reaction with iodine-starch paper


Analysis of the dialyzate for sulphuric, nitric and

hydrochloric acids


ANALYSIS OF THE DIALYSATE FOR SULPHURIC

ACIDDistillation at the presence of copper filings

Collection of the distillate into iodine solution

2H2SO4 + Cu H2SO3 + CuSO4 + H2O;

H2SO3 SO2 + H2O;

SO2 + I2 + 2H2O H2SO4 + 2HI;


ANALYSIS OF THE DIALYSATE FOR SULPHURIC ACID

Detection

Reaction with barium chloride → BaSO4 (white sediment)

Reaction with lead acetate → PbSO4 (white sediment)

PbSO4 + 4NaOH Na2PbO2 + Na2SO4 + 2H2O;

2PbSO4 + 2CH3COONH4

[Pb(CH3COO)2PbSO4] + (NH4)2SO4;


ANALYSIS OF THE DIALYSATE FOR SULPHURIC ACID

Detection

Reaction with sodium rhodisonate and barium salt → (red

colour of barium rhodisonate disappears at addition of

sulphuric acid)

O

O

O

O

O

O

O

O

O

O

ONa

ONa

O

O

O

O

O

O

H2SO

4

O

O

O

O

ONa

ONa

BaSO4

+ 2+

Ba Ba + +

2Na ;

Ba + + .


ANALYSIS OF THE DIALYSATE FOR NITRIC ACID

Distillation at the presence of copper filings

2HNO3 + 3Cu 2NO + 3CuO + H2O;

3CuO + 6HNO3 3Cu(NO3)2 + 3H2O;

2NO + O2 2NO2;

2NO2 + H2O HNO2 + HNO3;

Assay of the distillate for the presence of nitrogenous acid and nitrite



Detection

Reaction with diphenylamine → blue colour

NH

NH NH

N N

H

NO3

-

H2SO4

NO3

-

2

+. HSO4

-



Detection

•Reaction with brucine in concentrated sulphuric acid → red colour

•Colouring wool yellow when heating → yellow colour turns orange when

treating the sample by ammonium

Removal of nitrogenous acid and nitrite

(urea, ammonium salts, sulphanilic acid are added)

O C(NH2)2

2HNO2 + 2N2 + CO2 + 3H2O;

HNO2 + NH4Cl N2 + 2H2O + HCl;

HNO2 + HOSO2NH2 N2 + H2SO4 + H2O;


ANALYSIS OF THE DIALYSATE FOR HYDROCHLORIC ACID

•Reaction with silver nitrate → white sediment

HCl + AgNO3 AgCl + HNO3;

AgCl + 2NH4OH [Ag(NH3)2]Cl + 2H2O;

Assay of the distillate for the presence of sulphuric acid

Distillation from the dialysate

Detection

Reaction with potassium chlorate → colouring blue of iodine-starch paper

when iodine elaborating

KClO3 + 6HCl KCl + 3Cl2 + 3H2O;

Cl2 + 2Kl 2KCl + l2;


Analysis of the dialyzate for potassium hydroxide, sodium

hydroxide and ammonium hydroxide


ANALYSIS OF THE DIALYSATE FOR POTASSIUM HYDROXIDE

Precondition – strong alkaline aqueous extracts from the sample by

phenolphthalein (pH 8–10)

Assay for the presence of carbonate (addition of BaCl2)

Neutralization of the dialyzate by СН3СООН solution (рН= 3–4)

Detection

Reaction with sodium hydrotartrate → КНС4Н4О6 (white sediment

soluble in hot water, mineral acids and alkali)

Reaction with sodium cobaltinitrite (III) (Na3[Co(NO2)6]) →

К2Na[Co(NO2)6] ((yellow sediment)


ANALYSIS OF THE DIALYSATE FOR SODIUM HYDROXIDE

Precondition – strong alkaline aqueous extracts from the

sample by phenolphthalein (pH 8–10)

Neutralization of the dialyzate by СН3СООН solution

Detection

Reaction with potassium hydroxyl stibnate

K[Sb(OH)6] → КНС4Н4О6(white sediment soluble in hot water, mineral acids and alkali)

Reaction with uranyl zinc acetate

Zn(UO2)3(CH3COO)8 → NaZn(UO2)3(CH3COO)9(greenish-yellow crystalline sediment soluble in hot water and alkali)


ANALYSIS OF THE DIALYSATE FOR AMMONIUM HYDROXIDE

Assay for the presence of hydrogen sulphide (test with lead

acetate )

Reaction with litmus paper (red colour turns blue) and

reactive paper moistened by copper sulphate →

[Cu(NH3)4]SO4 (blue colour)

Reaction with Nessler’s reagent → yellowish brown or

orange brown sediment

I Hg

I Hg

NH

NH4

++ 2 [HgI4]

2- + 2OH-

I + 5 I-+ 2 H2O.


Analysis of the dialyzate for nitrite and nitrate


ANALYSIS OF THE DIALYSATE FOR NITRITE

Reaction with sulphanilic acid and β-naphthol → orange-

red colour

HNO2 + NH

2HO

3S NHO

3S N

NHO3S N

OH

N NNaO3S

+ HCl+

Cl-

+ 2 H2O ;

+Cl

-+ + 2 NaOH

+ NaCl + 2 H2O

NaO



Reaction with Griss reagent (sulphanilic acid and α-naphthyl

amine in acetic acid) → orange-red colour

NH2

HO3S NHO

3S N

NHO3S N

NH2

N NHO3S NH

2

HNO2 + + CH3COOH+

CH3COO-

+ H2O ;

+CH3COO

-+

+ CH3COOH .



Reaction with 1,8-naphthalene diamine → 1,8-azimino

naphthalene (orange-red colour solution or sediment)

NH2

NH2 N

N

N

H

HNO2 + + 2 H2O .

Reaction with iodine-starch paper → blue sport


ANALYSIS OF THE DIALYSATE FOR NITRATE

Assay for the presence of nitrite

(Nitrite can be decomposed by addition of sulphamic acid,

sodium azide or urea)

Reaction with diphenylamine → blue colour

Reaction with brucine in concentrated sulphuric acid →

red colour

Reaction with iron (III) sulphate and concentrated

sulphuric acid → brown ring around iron (III) sulphate

crystal



1. Therapeutic Drug Monitoring.

2. Environmental Toxicology.

3. Food Toxicology.

4. Occupational Toxicology.

5. Usage of mineral acids, alkalis, nitrites and nitrates in the national

economy and medicine.

6. Toxicity and treatment of nitrate and nitrite poisonings. Antidote

therapy.

7. Physical basis of the dialysis method.

8. Quantitation methods of mineral acids, alkalis and nitrites in dyalisate.

Students' Individual Work Tasks


This topic forms the basis of expert thinking, promotes the development of skills in the

field of Forensic and Clinical Toxicology (the Medical Examiner’s Offices, the

Emergency Centre for acutely poisoned patients, the Industrial Sanitary Laboratory

which performs industrial and ecological supervision, the Toxicological Laboratory for

Diagnostics of drug abuse and alcoholism).

The knowledge of toxicokinetics of mineral acids, alkalis, nitrites and

nitrates is necessary to a pharmacist to prevent intoxications by this group

of substances that are used as medications and in the production of

medicines.

This topic gives the methodical basis to the toxicologist to correctly construct

an algorithm for carrying out the toxicological research and interpreting its

results for this group of toxicants.

Сonclusions

Thank you for your attention


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Analytical Toxicology. Methodology of toxicological ...toxicchem.nuph.edu.ua/wp-content/uploads/2020/01/3... · Analytical Forensic Toxicology The task of Analytical Forensic Toxicology