1.4 Chromatography Flashcards
Types of chromatography
Thin layer chromatography
Gas chromatography
High-performance liquid chromatography
Ion chromatography
Mobile Phase
The liquid or gas
Stationary phase
A substance (usually a solid) that all particles can adhere to
Retardation factor
The ratio between the distance that the substance travels vs the distance moved by solvent front
What is adsorption?
The attachment of particles to the surface of a solid which occur when the secondary bonds form
What does the term ‘Tug of War’ mean regarding chromatography?
Chromatography is a ‘tug of war’ between the strength of adsorption to the stationary phase and the solubility in the mobile phase
What is chromatography used for?
The identification and separation of the components of mixtures.
Why does the separation occur?
Variation in the strength of the secondary bonds of the particles to the stationary and mobile phases due to a difference in the structure of the particles.
What factors impact the time/distance travelled by different compounds?
- Polarity of compound in relation to stationary phase
2. Polarity of compound in relation to mobile phase
What can you say about the compound that moves the furtherest?
Most like mobile phase
least like stationary phase
What can you say about the compound that moves the least?
most like stationary phase
least like mobile phase
What can you say about compounds with the same Rf or Retention time?
they are most likely the same compound
otherwise they have the same polarity
