- Paper chromatography
is the oldest method, the sample is spotted onto a paper strip, which is hung with its lower end into a solvent. Capillary action sucks the solvent upward past the sample. Separation usually occurs by partitioning of sample molecules between paper-bound water and the mobile organic phase.
- Thin layer chromatography
uses a solid support (glass plates, plastic or aluminium sheets) covered with a thin (0. 1–2mm) layer of the separation matrix. This layer is prepared by grinding the matrix material to a fine powder, mixing it with water to a thick slurry, and pouring it over the plates. Because different materials can be used as a matrix, this method is more versatile than paper chromatography.
- Column chromatography
uses columns filled with the matrix instead of thin sheets. The solvent is pushed...