Analytical chemistry Unit 2

Extraction

The physical transfer of a solute from one phase to another

Exhaustive Extraction

All solute is extracted into phase 2

Nonexhaustive extraction

A fraction of solute is extracted

Preconcentration

The process of concentrating trace components of a mixture before you actually analyze them

Mobile Phase

The solvent moving through the column (usually a liquid or a gas)

Stationary Phase

The solvent that stays in place inside the column

Adsorption Chromatography

The stationary phase solvent causes different types of mobile solvents to be adsorbed at different rates, causing them to be separated as they leave the column at different times

Partition Chromatography

Uses an open hollow column that causes solutes to maintain equilibrium between the column and the stationary (partition) solvent

Ion Exchange Chromatography

Anions or cations are attached to the walls of a column, causing oppositely charged solutes to bind to the column and not come out the other side

Size Exclusion/molecular exclusion/gel filtration/gel permeation chromatography

Beads with small pathways allow large solutes to freely move through the column while small particles are forced to move through the beads and move slower

Affinity Chromatography

Using antibodies for highly specific binding

Chromatogram

A graph showing the function of detector response in relation to elution time (how much response per amount of time passed)

Retention Time

Amount of time passed between the start of pouring a solvent and its detection

Retention Volume

The volume of mobile phase needed to elute a particular solute from the column

Adjusted Retention Time

The additional time the solute needs to travel through the column, beyond what is required by the solvent

Flow Rate (Volumetric Flow Rate)

The volume of solvent travelling through the column per unit time

Linear Velocity

Distance travelled by solvent per unit time

Retention Factor

Amount of time a sample spends in stationary phase over mobile phase. AKA Capacity factor/Capacity ratio

Relative Retention

Ratio of the adjusted retention times of two solutes. Sometimes called the separation factor

Partition Coefficient

The ratio of solute concentrations between the mobile and stationary phases