OVERVIEW OF INSTRUMENTAL ANALYSIS

Instrumental and Analytical Methodology in Forensic Science

Classes and Types of Evidence

  • Physical Evidence: Objects (fragments, tools, fibers, etc.)

  • Chemical Evidence: Drugs, toxic substances, paints, solvents, etc.

  • Biological Evidence: Blood, body fluids, hair, tissue, etc.

Examples of Evidence Types and Instrumental Methods

  • Blood, Body Fluids, Tissue:

    • Methods: Spectrophotometry, electrophoresis, IR and Raman spectroscopy.

  • Drugs and Toxic Substances:

    • Methods: UV, IR spectroscopy, HPLC, GC/MS.

  • Paints and Pigments:

    • Methods: IR and atomic absorption, polarized light microscopy.

  • Explosive Residues:

    • Methods: IR and Raman spectroscopy, HPLC.

  • Gunshot Residues:

    • Methods: Scanning electron microscopy, atomic absorption spectroscopy.

  • Accelerants, Solvents:

    • Methods: GC, GC/MS.

  • Hair:

    • Methods: Microscopy, electrophoresis.

  • Fibers:

    • Methods: Polarized light microscopy, IR, Raman.

Instrumental Methods and Their Applicability

  • Microscopy: General exams for biological evidence, questioned documents, etc.

  • Spectrophotometric/Spectral Methods: Applicable to drugs, organic dyes, inks.

  • SEM and Polarized Light: Used for gunshot residues and explosive residues.

  • SEPARATIONS:

  • Chromatographic Methods (GC, HPLC, TLC): For volatiles, drugs, inks, and other organic substances.

  • Mass Spectrometry: Identifies organic substances, drugs, accelerants.