C1 Air quality IC1.1 Chromatography Learning Objectives: To know how chromatography works. To be able to calculate R f values for paper chromatography. Key words: chromatography, mobile phase, stationary phase, Read p to find out more about chromatography

C1 Air quality IC1.1 Chromatography as an application of dynamic equilibrium Paper chromatogrpahy: Mobile phase = solvent (often water) that moves up the stationary phase carrying with it the sample. Stationary phase = solid material that the mobile phase moves over and which can hold onto pigments (compounds) in the sample. Samples can be identified by seeing how far they move up the stationary phase compared to reference samples, which are known. OR They can be identified using their RETARDATION FACTOR R f = distance moved by the chemical distance moved by the solvent

C1 Air quality IC1.1 Summary GC TLC Paper chromatography

C1 Air quality IC1.1 TLC The stationary phase is an absorbent solid supported on a stiff plastic sheet or glass plate. The mobile phase is a solvent in which the sample is soluble. It may be 1 liquid or a mixture. The right choice of solvent is vital when separating complex mixtures, such as in drug analysis.

C1 Air quality IC1.1 Advantages and disadvantages Type of analysisAdvantagesDisadvantages GC TLC Paper chromatography