Shubham choudhary presentation MSC (0.001).pdf

Sometimes

1. SEMINAR REPORT ON
CHEMISTRY OF FINGERPRINTS
SESSION 2022-24
DEPARTMENT OF CHEMISTRY
Presented By
??????????????????�??????�??????????????????????????????????????????�????????????
Class Roll No. : 22MSC21
University Roll No. : 202201204032041
MSC Chemistry 4
th
Semester
Under the Guidance of all the faculty members of chemistry department

2. CONTENTS
1.Introduction
2.Types of fingerprints
3.Composition of fingerprints
4.Types of Surfaces
5.Analysis:-
{ i} Physical Methods
{ii} Chemical Methods
1.Conclusion
2.Reference

3. INTRODUCTION
1.Vitalprocessthatanalyzeandidentifiesuniquepatternsonfingertips.
•2.Highlightsthesignificanceoffingerprintdeterminationin
variousfields
•3.Itsessentialroleinpersonalidentification,forensicinvestigations
andsecuritysystems.

4. First systematic attempt at
personal identification was done
by –Alphonse Bertillon (1883). He
was the French police expert .
This system relied on detailed
bodily description which
included:-
Full length,Profilephotograph
,Systematic precise body
measurements .

5. William Herschel-He was an English civil servant in India.
He started using fingerprint to signature contract, but he
didn’t publish anything.
Henry Fauld-Scottish physician, he works in hospital in
Japan. He published his view on –potential application of
fingerprint.
In 1880 Falls suggested that-skin ridges pattern can
contribute in personal identification
Francis Galton (1892) published a book “FINGERPRINT” in
this book he discovered the anatomy of fingerprints and
methods of recording it.

7. • VISIBLE FINGERPRINTS
Easily seen with the naked eye because of the presence of a
coloredsubstance, such as ink, blood or dust, among others.It
is only necessary to photograpthe fingerprint.
• PLASTIC FINGERPRINTS
when the finger is pressed against a malleable substance,
creating a mold.Theprint can also be directly photographed or
a moldcan be made with a casting material.

8. LATENT FINGERPRINTS
• Most commonly found at crime scenes and being invisible to the
naked eye.Opticaltechniques would always be used, because they
are easy to use.
• Most of the time these techniques are not enough, and a physical
or chemical process is required in order to provide colour.
• The selection of the most suitable developer for each situation
depends mainly on two factors.
• The composition of the particular fingerprint, and the surface on
which the fingerprint is located.

9. COMPOSITION OF FINGERPRINTS
Thecompositionofthefingerprintsiscomplex,asit
depends
onintrinsicandextrinsicfactors.
●INTRINSICCOMPONENT
Fingerprintsaremainlythenatural
secretionsoftheexocrineandsebaceous
glands.Theexocrineglandsarepresent
throughoutthebodyandtheirsecretionis
mostlycomposedofwater,alongwithamino
acids,proteins,urea,metalions,sulfates,
phosphates,carbonatesandammonia.

10. ●EXTRINSIC COMPONENTS
Fingerprintsaresubstancesthatapersonmayhavecontact
withduringtheday,suchasdust,cosmetics,blood,grease
etc.Inaddition,environmentalfactorssuchasclimateand
weathercaninfluence,becauseevaporationofvolatiles,
actionofmicroorganismsandoxidationcanoccur,
affectingthecomposition.
The sebaceous glands are present in the regions of the
body where there are hair follicles and their secretion
(sebum) is composed of triglycerides, free fatty acids
and other lipidicesters.

11. TYPES OF SURFACES
●POROUS SURFACE
Whenafingerprintisdeposited,itscompounds
migratebeneathit,becausethesesurfacesare
mostlyabsorbent.Itisrecommendedtheuseof
reagentsthatinteractwithaminoacids,because
whentheyareabsorbed,theyremainstationary.
●NON-POROUSSURFACE
Smoothorrough,areoftenfoundatcrime
scenes.Havingnopores,thefingerprint
becomesadepositonthesurfacethatcanbe
easilydestroyed

12. FINGERPRINT
ANALYSIS
●PHYSICAL METHOD
●CHEMICAL METHOD

13. PHYSICAL METHODS
• POWDER TECHNIQUE
Powderdustinginvolvestheuseoffinepowdersto
visualizelatentfingerprints.worksbestonsmooth
nonporoussurfacessuchasglass,certainplasticsbut
islesseffectiveonporoussurfacessuchaspaperor
cardboard(theresiduetendstoabsorbintothefibers
overtime)oronwetorstickysurfaces.Amongthe
manycomponentsoffingerprintresidue,sebumand
perspirationtendtoadheretopowderparticles,
nonporoussurfacesdonotadherewelltopowder
particles,allows for fingerprint
development.Investigatorsusemanydifferenttypesof
powders.Mostblackpowdersaremadefromfine
carbon.

14. ●IODINE METHOD
[•]Iodineisapurplesolidwhenitistoohotand
underpressure.Wheniodinecrystalsareheated,
theywillsublime,producingiodinevapors.
[•]Thesevapoursarethoughttobeabsorbedbythe
fingerprintresiduesothattheyproducea
temporaryambercoloredproductwhichbecomes
fade.
[•]Onetechniqueemploysthereactionofiodine
withstarchtoproduceastabledarkbluecoloured
product.
[•]Iodinefumingisoneoftheoldestfingerprint
developmenttechniques;itworkswellonporous
surfaces.

16. ●VACUUMMETAL
DEPOSITION
•VMD has successfully developed fingerprints on all types of surfaces
including plastic, cloth, glass & paper currency.
•When small amount of metals are vapourizedin a vacuum chamber, the
vapours adhere to the surface of the subject everywhere but along the
friction ridges.
•The friction ridges are visible on the object because the background is
coated with vapourizedmetal while the friction remains transparent.
•The vacuum evaporates the air so the metal vapours do not have to
complete with the air molecules.

17. CHEMICAL METHODS
●SILVER NITRATE
Theuseofsilvernitrateforfingerprint
developmentisoneoftheoldesttechniques,used
since1891,althoughtodayitislessused.This
methodisbasedonthefactthatthesodium
chlorideofthedepositionorsweatinthelatent
impressionreactwithsilvernitratetoformsilver
chloride.

18. Thisreagentworkswellonporoussurfaces
suchasPaper,cardboard&rawunpainted
wood.
• Then, the silver chloride formed,whichis light sensitive
& break into its individual components silver & chloride . .
• Elemental silver has a dark grey colour, which makes the
visualization of the fingerprint possible.

19. ●NINHYDRIN REACTION
• Discovered by –Siegfried Ruhemannin 1910 .
• Ninhydrinalso known as –Triketohydrindenehydrate,whichis a hydrocarbon
compound (C
9H
6O
4 ).
• Ninhydrinreact with amino acid present in the sweat.
• It is white colour solid .
• Ninhydrinmethod is basically a redox reaction ,which acts as a oxidising agent .
• It react with free amino group of the amino acids & oxidised the compound .

22. • CONCLUSION
Several substances and techniques that are used in
the development of latent fingerprints were
presented.
The procedures and compounds presented act in a
physical or chemical way on fingerprint residues,
making them visible in order to provide evidence and
assist the criminal justice system
It is important to note that there are other methods of
fingerprint development, especially the optical
methods, which are always the first option because
they are non-destructive.

23. Furthermore, it should be pointed out that
several substances and methods were used
in the past, but due to research related to
safety and efficiency, they are being left
aside, while other methods remain very
popular and are used all over the world, and
there are still those that are new and still
being researched, such as different green
developers and nanomaterials.

24. REFERENCES
●FingerprintDevelopmentTechniques:AReview
FingerprintDevelopmentTechniques:AReviewRafaelaG.
Ferreira,RachelB.A.Paula,AdrianaA.Okuma,Luciana
M.COSTA
DOI:http://dx.doi.org/10.21577/1984-6835.2021008
●www.google.com
●https://youtu.be/_eskOcx-5u8?si=bPBULw_4_6jOB5O1

25. THANK
YOU