A level Chemistry · Edexcel 9CH0 · Topic 19B
Chromatography
Key points
- Chromatography separates components by their different distribution between a stationary phase and a mobile phase.
- TLC: stationary phase is silica or alumina on a plate; . Visualise colourless spots with UV light or iodine.
- Gas chromatography (GC): an inert carrier gas moves the vaporised sample through a column; components are identified by retention time and quantities by peak area.
- HPLC uses a liquid mobile phase pumped at high pressure through tightly packed solid particles.
- Linking GC or HPLC with a mass spectrometer identifies each separated component.
- Uses: checking reaction progress and purity, testing for drugs, analysing amino acids.
Topic notesPremium
Chromatography separates the components of a mixture so that they can be identified and measured. All its forms work on the same principle, and the A level types (TLC, gas chromatography and HPLC) differ mainly in what the two phases are.
Unlock the full notes with Premium
Premium includes full topic notes, the paper generator, self-quizzes and progress tracking.
Practise this topicPremium
Premium members can generate an exam-style paper with a mark scheme, or take a quick quiz, on Chromatography.