Chromatography and polymers

Mobile vs stationary phase

The mobile phase (liquid or gas) transports the sample mixture through a stationary phase (solid or liquid support), separating components based on their differential affinity between the two phases.

Affinity vs Polarity?

An atom's desire to grab electrons vs the resulting uneven sharing of those electrons within a bond or molecule, creating positive and negative poles

Adsorption vs Desorption

Solvent front

The furthest point the solvent (mobile phase) travels up a chromatography plate or paper

Components in purple dye have different _______ for the _________ and ________ phase

affinity, stationary, mobility

The blue component of purple dye spends more time___________ in the ________ phase, because it is quite polar.

desorped, mobile

The red component of purple dye spends more time __________ in the ________ phase, because it has a low polarity

adsorpted, stationary

Adsorption vs desorption

attached to the stationary phase vs dissolved back into the mobile phase

How do you calculate the retention factor?

Rf = distance travelled by component/distance travelled by solvent front

Two samples with the same _________ and the same_________are highly likely to be the same

Rf value, conditions

Thin Layer Chromatography (TLC)

Uses a thin layer of solid sprayed onto a backing plate and the analyte moves upwards

Column Chromatography

Stationary phase is packed beads in a column, eluent moves top to bottom through gravity or pressure

Analyte

Substance being separated

Eluent

The solvent used to carry the analyte through the stationary phase

Chromatography?

A technique for separating chemicals in a mixture

How does separation occur?

The solute spends some time dissolved in the mobile phase and some time stuck to the stationary phase

Why are components separated?

Based on having different affinities for the stationary phase

Component spends more time adsorped

Has the strongest IMF between itself and the stationary phase

High Performance Liquid Chromatography

A form of column chromatography, stationary phase is a solid or viscous liquid chosen to give good separation, mobile phase is a solvent pumped through under high pressure, UV is absorbed by any molecules in the eluent, seen through a chromatogram

Chromatogram

Minimum number of components, concentration, retention time

Have higher retention time

heavier molecules

What are polymers?

Molecules made of thousands of units strung together into very long chains

Simplest molecule strung together in a polymer

Monomoer