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Column Chromatography (A2 Only)

Chemistry: AQA A Level, topic 6.10.3

Column Chromatography

Column chromatography is one of the most commonly used methods for separating substances.

Experimental set up

Experimental set up

  • A glass column is packed with a solid support (normally silica).
  • The sample mixture is added above this, in the column.
  • An organic solvent is added which moves the sample down the solid support and through the column.
Mobile and stationary phases

Mobile and stationary phases

  • The solid support is the stationary phase.
  • The organic solvent is the mobile phase.
  • The more apolar substances are more soluble in the organic solvent. They interact more with the mobile phase and so run quickly through the column. They have a smaller retention time.
  • The more polar substances are less soluble and interact more with the stationary phase. They have a larger retention time.
Experimental procedure

Experimental procedure

  • Above shows the step-by-step process of separating substances using column chromatography.

Test yourself on Column Chromatography (A2 Only)

  • What is the solid support often made from in column chromatography?

  • Which of the following is most soluble in the organic solvent (column chromatography)?

  • Which of the following has the longest retention time in column chromatography?

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