What is chromatography?
chromatography is a versatile technique for separating mixtures
strategy: flow the mixture over a material that retains some components more than others, so different components flow over the material at different speeds
a simple analogy for chromatography
mixed swarm of bees and wasps swept by the wind over a flower bed...
bees visit flowers; wasps stay airborne
wasps leave the bed first; swarm separated on the basis of affinity for flowers
in chromatography, a mobile phase sweeps the sample over a stationary phase (as the wind sweeps the swarm over the flower bed)