[1] It is performed on a TLC plate made up of a non-reactive solid coated with a thin layer of adsorbent material.

[7] Testing different stationary and mobile phases is often necessary to obtain well-defined and separated spots.

[citation needed] TLC is quick, simple, and gives high sensitivity for a relatively low cost.

[5] The process for TLC is similar to paper chromatography but provides faster runs, better separations, and the choice between different stationary phases.

To make sure there is sufficient compound to obtain a visible result, the spotting procedure can be repeated.

Development: The TLC plate is placed in the container such that the sample spot(s) are not submerged into the mobile phase.

[11] An eluotropic series, which orders solvents by how much they move compounds, can help in selecting a mobile phase.

[5][12] While single-solvent mobile phases can sometimes give good separation, some cases may require solvent mixtures.

[14] As the chemicals being separated may be colourless, several methods exist to visualise the spots: TLC plates are usually commercially available, with standard particle size ranges to improve reproducibility.

[4] They are prepared by mixing the adsorbent, such as silica gel, with a small amount of inert binder like calcium sulfate (gypsum) and water.

[20] The researchers react an alcohol and a catalyst directly in the co-spot of a TLC plate before developing it.

Compound characterization with TLC is also possible[citation needed] and is similar to reaction monitoring.

Big preparative TLC plates with thick silica gel coatings can separate more than 100 mg of material.

[22] For larger-scale purification and isolation, TLC is useful to quickly test solvent mixtures before running flash column chromatography on a large batch of impure material.

[24] The eluent from flash column chromatography gets collected across several containers (for example, test tubes) called fractions.

[citation needed] Furthermore, two-dimensional TLC[4] can help check if a compound is stable on a particular stationary phase.

If the target compound appears on the diagonal of the square, it is stable on the chosen stationary phase.

TLC is also an analytical method for the direct separation of enantiomers and the control of enantiomeric purity, e.g. active pharmaceutical ingredients (APIs) that are chiral.