Forensic Analysis - Chrom3

These flashcards cover key terms and concepts related to chromatography, with a focus on liquid-liquid extraction and solid-phase extraction methods influenced by pH.

Liquid-Liquid Extraction (LLE)

A technique that involves the separation of compounds based on their solubility in two immiscible liquids.

Partition Coefficient

A ratio that indicates how a compound distributes between two phases, often used in extraction methods.

pH

A measure of the acidity or basicity of a solution, influencing the ionization state of analytes.

Ionization

The process by which an atom or molecule acquires a negative or positive charge by gaining or losing electrons.

Acidic Environment

A condition where the pH is less than 7, typically enhancing the ionization of acidic analytes.

Basic Environment

A condition where the pH is greater than 7, generally leading to increased ionization of basic analytes.

pKa

The negative logarithm of the acid dissociation constant (Ka), that indicates the strength of an acid.

Le Chatelier’s Principle

A principle that states a system in equilibrium will adjust to counteract any external changes.

Solid Phase Extraction (SPE)

A sample preparation technique that separates compounds based on affinity to a solid stationary phase.

Ion Exchange SPE

A form of SPE that relies on the electrostatic attraction between charged analytes and oppositely charged groups on the stationary phase.

Reverse Phase SPE

A technique using a non-polar stationary phase and a polar liquid phase to separate compounds.

Normal Phase SPE

A technique that employs a polar stationary phase with a non-polar liquid phase for separation.

Non-ionized Molecules

Molecules that do not carry a charge, often more hydrophobic and lipophilic.

Hydrophilic

Substances that are attracted to water; typically polar or ionic compounds.

Lipophilic

Substances that are attracted to fats and non-polar solvents.

Separation Efficiency

The effectiveness of a separation technique in producing distinct layers of analytes based on their properties.

Aqueous Layer

The layer in a liquid-liquid extraction that contains water; typically holds polar compounds.

Organic Layer

The non-aqueous layer in liquid-liquid extraction, often containing non-polar compounds.

Polar Solvent

A solvent that has a significant dielectric constant and can dissolve ionic and polar solutes.

Non-polar Solvent

A solvent that does not have a significant dielectric constant and is typically unable to dissolve ionic compounds.