A concise HTML summary of what students are expected to know about chromatography in A-level Chemistry.
In A-level Chemistry, chromatography is usually taught as part of analytical techniques or organic analysis. Students learn how mixtures are separated, how chromatograms are interpreted, and how values such as Rf values and retention times are used to identify substances.
Chromatography separates the components of a mixture using a mobile phase and a stationary phase. Different substances move differently because they interact with these phases to different extents.
Students should be able to calculate and use Rf values to help identify substances.
In gas chromatography and other column methods, substances can be identified by their retention times. Peak area may also be used to estimate the amount present.
Students may also learn that chromatography can be used with mass spectrometry to analyse substances in contexts such as forensics and sports drug testing.