Forensic Science and Chromatography

These flashcards cover essential concepts in forensic science relating to inorganic substances, techniques for analysis like chromatography and spectroscopy, and the principles of fingerprint analysis.

Inorganic substance

A substance that does not contain carbon and may be encountered as physical evidence in forensic science.

Emission spectroscopy

A technique that collects and measures the various light energies emitted by excited atoms.

Atomic absorption spectrophotometry

A technique that measures the amount of light energy absorbed by an atom when exciting electrons.

Rf value

A numerical value assigned to the distance a spot travels in thin-layer chromatography, indicating the ratio of the distance traveled by the compound to the distance traveled by the solvent.

Chromatography

A technique used to separate and tentatively identify the components of a mixture based on their preference for either a stationary or moving phase.

Qualitative analysis

An analysis that relates to the identity of the material without quantifying its amount.

Quantitative analysis

An analysis that requires the determination of the percent composition of the components of a mixture.

High Performance Liquid Chromatography (HPLC)

A technique that separates compounds using a stationary phase and a mobile liquid phase that operates at room temperature.

Electrophoresis

A technique where materials are forced to move across a gel-coated plate under an electric potential for separation of substances.

Mass spectrometry

A technique that identifies chemicals present in a sample by measuring the mass of its ions after they are fragmented.

Friction ridges

The raised patterns on fingers and palms that create unique fingerprints; designed for grip and resistance to slippage.

Latent prints

Fingerprints that are not visible to the naked eye but can be developed using various techniques such as powders or chemical treatments.

Organic substances

Chemical compounds that typically contain carbon and are often found in biological materials.

Spectrophotometry

The study of the absorption of light by chemical substances to identify and quantify materials.

X-ray diffraction

A method used to study solid crystalline materials by analyzing the pattern formed when X-rays are reflected off atomic planes.

Neutron activation analysis

A technique used to identify and quantify elements in a sample by measuring the gamma rays emitted from radioactive isotopes.

Beer’s Law

A principle stating that the quantity of light absorbed by a substance is directly proportional to its concentration.

Chromatogram

The written record of the separation of components in gas chromatography.

Photons

Discrete packets of light energy that describe how light behaves when absorbed by substances.