Chromatography Principles and Techniques

Vocabulary-style flashcards covering the definitions, types, and components of chromatography as presented in the lecture notes.

Chromatography

A laboratory technique for the separation of a mixture into its components by passing it through a system where components travel at different velocities.

Mobile phase

A fluid solvent (gas or liquid) that carries the mixture through a system such as a column, capillary tube, plate, or sheet.

Stationary phase

A material fixed in place in the chromatography system (e.g., silica layer in TLC) that interacts with the constituents of the mixture.

Preparative chromatography

A form of purification whose purpose is to separate the components of a mixture for later use.

Analytical chromatography

Chromatography done with smaller amounts of material to establish the presence or measure the relative proportions of analytes in a mixture.

Analyte

The specific substance that is to be separated during the chromatography process.

Chromatogram

The visual output produced by a chromatograph.

Chromatograph

An instrument that enables sophisticated separations, such as gas chromatographic or liquid chromatographic separations.

Eluent

The solvent or solvent mixture used in elution chromatography; it is synonymous with the mobile phase.

Eluate

The mixture of solute and solvent that exits the chromatography column.

Retention time

The characteristic time it takes for a particular analyte to pass through the system from the column inlet to the detector under set conditions.

Column chromatography

A separation technique in which the stationary bed is contained within a tube.

Packed column

A column where particles of the solid stationary phase (or support coated with liquid) fill the entire inside volume of the tube.

Open tubular column

A column where the stationary phase is concentrated along the inside tube wall, leaving an unrestricted path for the mobile phase in the middle.

Paper chromatography

A technique using a strip of cellulose paper as the stationary phase; substances travel further if they are less polar.

Thin-layer chromatography (TLC)

A technique using a stationary phase of an adsorbent like silica gel, alumina, or cellulose coated on a flat, inert substrate.

Gas chromatography (GC)

A separation technique also known as gas-liquid chromatography (GLC) where the mobile phase is a gas, typically helium.

Porous layer open tubular (PLOT) columns

A type of capillary column used in GC where the stationary phase is adsorbed to the column walls.

Wall-coated open tubular (WCOT) columns

A type of capillary column used in GC where the stationary phase is chemically bonded to the column walls.

Support-coated open tubular (SCOT) columns

A type of capillary column that combines support particles adhered to walls with a liquid phase chemically bonded onto those particles.

High-performance liquid chromatography (HPLC)

A form of liquid chromatography that utilizes very small packing particles and relatively high pressure to force the mobile phase through the column.

Monoliths

Sponge-like chromatographic media made up of an unending block of organic or inorganic parts.

Normal phase liquid chromatography (NPLC)

A chromatography method where the stationary phase (e.g., silica) is more polar than the mobile phase (e.g., toluene).

Reversed phase liquid chromatography (RPLC)

A chromatography method where the mobile phase (e.g., water-methanol) is more polar than the stationary phase (e.g., $C_{18}$ octadecylsilyl).