Application of case study and role-playing in forensic chemistry education

Application of case study and role-

playing in forensic chemistry

education

Dr Renata Wietecha-PosłusznyLaboratory for Forensic Chemistry, Department of Analytical

Chemistry, Jagiellonian University, Krakow

Way we use didactic method?

tactic of educational process; making students an active element of educational

process by motivating them to participate to curricular and extracurricular activities;

find solution to cognition tasks and problems creating an alliance professor-student;

develop logical and factual thinking at same rate; determination of professor as moderator and observer

during educational process; to open paths and possibilities of discovering and

understanding reality; research technical possibilities; develop cultural background; etc.

2FINAL Tempus-EDUFORMARK WORKSHOP, Skopje,15.02.2010

FINAL Tempus-EDUFORMARK WORKSHOP, Skopje,15.02.2010

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Didactic techniques

Case study Role-playing Group working Learning in Context Brainstorming Problems of Base

Learning Projects etc.

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Laboratory Class of Forensic Chemistry at Jagiellonian

University The class is conducted at the Faculty of

Chemistry of the Jagiellonian University within the course “Chemical investigations in criminalistics and toxicology”

The duration of classes comprises of two teaching/learning units, 7.5 lesson hrs each (1.5 hrs - seminary and 6 hrs – laboratory class).

Classes are for four-year students of chemistry, forensic chemistry panel

the group consists of six students


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Title: Application of the AFS method

to post-mortem examination of acute toxic metal

poisoning

Forensic Laboratory Class - example


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Forensic Laboratory Class - example

Aims: To introduce students to every step

of the toxicological expertises and the way

of writing expert opinions

To explain the chemical and physical background of atomic fluorescence spectrometry and digestion technique


Steps of laboratory class

The seminar part: (i.e. presentation and discussion)

films or short newspaper articles (case background) - short crime stories or unsolved crimes

material evidences

The experimental part:

preparing of material evidences (working in small teams) - digestion of samples

analysis of biological and another samples by HG-AFS technique

The expert’s report



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Presentation of the topic and discussion in the seminar room

Fails and material evidence - Instruction and reporting officer’s narrative

Decision about: essential analyses, possible methods, available time and equipment

X – files - Presentation of case background

Decision of the prosecutor to appoint expert

Discussion about the theoretical topics and brainstorming

Part of seminar


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Sort of poisons

famous historical poison - ”Poison of King” or „Aqua Tofana" ; no smell, no taste and easy soluble in water

strong toxic effect: (Seńczuk 1999) toxic dose 70-300 mg (WHO 1993) symptoms of arsenic poisoning include: violent

stomach pains, vomiting and delirium, cancer disease (Bescher i in 1993)


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Famous cases

Maria Capelle - Lafarge "Maria Lafarge"

prominent people throughout history (Napoleon Bonaparte, George III of the United Kingdom

tricky housewife or husbands

Seminar part - Case studies


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Fatal arsenic poisoningI’m

lost. It is the

end!

Few minutes later, a clerk looks carefully to the document, they gave him. Some writings look suspicious and he decides to call the police

But both robbers, just before being clapped in irons, eat portions of white powder. Soon, in the local brig, they get sick and die despite the medical treatment

After short chasing, police arrest suspects and recover the money

Two men visit the bank. They have a paper allowing them to take 1,500,000 zlotys (215,000 GBP)


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Seminar part - Case studies

Fatal selenium poisoning

A 22-year-old student of biology was carrying out experiments for her Master’s thesis. Suddenly she went to the toilet and vomited violently. She had severe diarrhea and complained of abdominal pains.

What is wrong with this experiment?! Ohh…I hated it!

After admission to hospital, she developed cardiovascular failure, and therefore, was subjected to intensive treatment, moreover doctors noticed a strange smell from her whole body.

Just before passing away, she had confessed that she had ingested about 20 ml of sodium tetraoxoselenate(VI) with suicidal intent.


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Decision of the prosecutor to appoint the expert


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Material evidence

the following items are taken as evidence from the crime scene (e.g. the bottle of wine, the glass and its contents etc.)

autopsy material (blood, urine, hair, section of internal organs: liver, lung, brain etc.)

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Steps in hair sample preparations for toxicological analysis

IV step

Pre - analytical

Decontamination

Segmentation

Weighing of hair segments and fragmentation

Sample preparation

Matrix destruction

AFS or AAS or ICP-MS

Analyte enrichment

Extraction or digestion of hair matrix

Clean –up of hair extract

Pre-test by immunoassay

GC-MS or GC-MS-MS or LC-MS-MS

Analysis of washings

For drugsFor elements

I step

II step

III step

IV step

V step


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Principle of Atomic Fluorescence Spectrometry

Excitation Process

AtomicFluorescenceSpectra

De-Excitation ProcessEo

Ei

Light Energy

E=h

Experimental part - Mysterious Suicides


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Preparing of material evidences

Experimental part - Mysterious Suicides

Analysing of all samples, obtaining data

FINAL Tempus-EDUFORMARK WORKSHOP, Skopje,15.02.2010 18


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Parts of expert opinion

introduction - description of all material evidences

body - an account of the analysis steps and the obtained results

Conclusion - answer to proposed questions from prosecutor

Like an Expert - Role-plays


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Team prepares its exercise report according to rules of the expert opinion for trial purposes.

1. Description of evidence

2. Account of measurements

3. Answers to prosecutor’s questions

4. ConclusionsCase Closed!prawo.gazetaprawna.pl


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Laboratory Class of Forensic Chemistry December 2009 – students from Macedonia

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References

1. Seńczuk W. [red.], Toksykologia, PZWL, Warszawa, 1999, 437-509.

2. Kościelniak P., Problematyka kalibracji w analizie chemicznej,

Chemia Środowiska cz.2, 277-301.

3. Namieśnik J.[red.], Przygotowanie próbek środowiskowych do analizy,

Wydawnictwo Naukowo-Techniczne Warszawa, 1999, 56-67.

4. Szczepaniak W.[red.], Metody instrumentalne w analizie chemicznej,

PWN, Warszawa 2004, 22-29.

5. Walas S., Atomowa spektrometria fluorescencyjna (ASF) – cz I i II.–

Analityka, nr.: 2 i 3, 2002 odpowiednio 10-11 oraz 9-12.

Additional

1.Klewska A.., Przygotowanie materiału biologicznego do oznaczania

śladów metali,

Z Zagadnień Kryminalistyki, 3, 1968, 62-67.

2.Stryer L., Biochemia, PWN, Warszawa, 2003, 280-360

3.Katz S. H., Chatt A. [red.], Hair Analysis – Applications in the

Biomedical and Environmental Sciences, VCH, Weinheim 1988.

4.Sanz M., Romero F., Romero C., Selenium and cancer: some

nutritional aspects, Review article, Nutrition, 16, 2000, 376-383


Conclusions

Using the variety didactic method help to improve

student practical skills such as: observation,

interpretation, problem solving, team work, experiment

design, data maintenance and analysis, communication

and presentation, laboratory and interpersonal ability,

leadership capabilities etc.

The form of laboratory class help to increase

students’ interest and motivation

Obtained skills during experimental work are

valuable in the future carrier as a forensic expert


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Thank you

for your attention


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Application of case study and role-playing in forensic chemistry education