VISUALIZATION OF LATENT FIGERPRINT USING SILICA GEL G: A NEW TECHINIQUE, By Bhoomi Aggrawal

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ABOUT THE AUTHOR

Meet Bhoomi, a dedicated student pursuing a Bachelor's degree in Forensic Science. With a passion for experimental exploration in her field, Bhoomi aspires to contribute to the pursuit of justice within the domain of forensic science and law.

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ABSTRACT

Latent fingerprints are a common source of information for forensic experts and law enforcement agencies. The thin layer chromatography (TLC) plates that are prepared in this work are made with silica gel G powder. Latent fingerprint remnants are made up of secretions from the nose, palm, and sebaceous, apocrine, and eccrine glands (sweat). However, the quest for more versatile and effective techniques persisted, leading to the emergence of innovative approaches like Silica Gel G powder. The silicon atoms are linked to –OH groups at the silica gel’s surface. A latent fingerprint is an imprint left by direct contact with a surface or object that is not apparent to the unaided eye. The advantages of using Silica Gel G powder for latent fingerprint visualization underscore its significance as an innovative technique in forensic science. The latent fingerprints were developed on each of the several substrates using Merck Specialties Private Limited’s white-colored silica gel G powder. There are several techniques in the literature for creating latent fingerprints. The emergence of Silica Gel G powder in forensic science represents a significant breakthrough in the visualization of latent fingerprints. The process of using Silica Gel G powder for latent fingerprint visualization exemplifies the precision and

attention to detail required in forensic investigations.

INTRODUCTION:

Fingerprints are the distant phalanges of fingers and thumb that replicate a pattern of friction ridges. Dactyloscopy is the examination-based study of fingerprint identification. The name observation. It is the examination of the ridges on the hand's interior surface. Because each person's fingerprints are different, this technique of identifying people has been accepted for more than a century. Forensic investigations regard fingerprints as among the most useful physical evidence types. In most crime scenes, fingerprints can be found. They serve as a means of identifying the suspect or offender and are discovered on items found at crime scenes. 15 Finger ridges contain a large number of sweat pores. 7,16,51 A latent fingerprint is an imprint left by direct contact with a surface or object that is not apparent to the unaided eye. The natural oils and moisture that the human body produces are transferred when the friction ridges come into touch with one another, creating the print. 15,31 Latent fingerprint remnants are made up of secretions from the nose, palm, and sebaceous, apocrine, and eccrine glands (sweat). Minerals (0.5%), organic substances (0.5%), and water (>98%) are all present in sweat. 1,8 Chloride, calcium, Sulphur, urea, lactic acid, amino acids, phenol, sodium, potassium, and ammonia, cholesterol, free fatty acids, wax esters with diglycerides and triglycerides, etc. are among the components of latent print residue. 2 Glycerides, fatty acids, wax esters, squalene, and sterol esters are found in sebaceous sweat, whereas proteins, urea, amino acids, uric acid, lactic acid, sugars, creatinine, and choline are found in eccrine sweat. The chemical makeup of latent finger impressions is influenced by several donor-related variables, including sex, age, food, disease type, medication, and the presence of pollutants on the fingertips' surface. 21,52 As time passes, the latent residue's chemical makeup varies even more because of its volatile components evaporating, microorganisms at work, and exposure to heat, light, moisture, and air. 17-19 Forensic experts have yet to solve the puzzle of how to produce and visualize latent fingerprints on some odd substrates. There are several techniques in the literature for creating latent fingerprints. Hydrophobic particles based on silica have been produced recently for the purpose of seeing latent fingerprints. 3,28,29 However, the powdering approach is the conventional technique for creating fingerprints. 4 This work has developed a novel substance (powder) that may be applied to latent fingerprints that are present on porous and nonporous substrates. The thin layer chromatography (TLC) plates that are prepared in this work are made with silica gel G powder. For lab work, this powder is readily available. The diagram shows a small part of the silica surface. 14

The powder known as silica gel G is silicon dioxide (silica) combined with gypsum as a binder. Large covalent structures are formed when oxygen atoms connect silicon atoms. The silicon atoms are linked

to –OH groups at the silica gel's surface. Because of its –OH groups, the silica gel's surface is highly polar and can form hydrogen bonds with nearby molecules as well as dipole–dipole attractions and Vander Waals dispersion forces. 5

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