MUHWA Borosilicate Glass TLC Chamber — Square, with Ground-Glass Lid
A TLC chamber's entire function is to hold solvent vapor. The mobile phase at the bottom produces a saturated atmosphere; your spotted TLC plate leans against the wall; the solvent climbs the plate by capillary action, and the vapor saturation keeps the solvent front even and straight. If the lid doesn't seal, the vapor leaks out, the solvent front smiles or frowns, and your Rf values become unpredictable.
The ground-glass lid-to-chamber interface is the seal. Ground glass works without a gasket — the mating surfaces are flat enough that vapor doesn't escape. When you put the lid on, give it a gentle press and a quarter-turn twist — this seats the ground surfaces together. Don't grease the joint (as you would with a vacuum desiccator) — grease dissolves in organic solvent vapor and will end up in your mobile phase. The square shape accommodates standard 5x10cm and 10x10cm TLC plates — the plate leans diagonally or against one wall, and the chamber width gives the solvent front room to rise without the plate touching the opposite wall.
Borosilicate glass — why it matters
TLC mobile phases are aggressive solvent mixtures: ethyl acetate/hexane, dichloromethane/methanol, toluene/acetone, sometimes with a splash of acetic acid or triethylamine. Borosilicate glass handles all of these at room temperature. It doesn't swell, doesn't dissolve, doesn't leach extractable organic compounds that would show up as ghost spots on your plate. The glass is thick enough to resist thermal shock if you warm the chamber slightly to speed saturation, but don't heat it on a hot plate — use a water bath if you need elevated temperature.
Specifications
| Shape | Square (accommodates 5x10cm and 10x10cm plates) |
| Material | Borosilicate glass |
| Lid | Ground-glass, flat |
| Typical solvent volume | ~20-50mL (5mm depth in chamber base) |
Running a TLC step by step
Pour your mobile phase into the chamber — about 5mm deep, enough to cover the bottom but well below the origin line of your plate. Lean a piece of filter paper against the inside wall — the paper wicks solvent and speeds vapor saturation. Close the lid and let the chamber equilibrate for 10-15 minutes. Meanwhile, spot your TLC plate with samples and standards. After equilibration, open the chamber, lean the plate against the wall (sample spots above the solvent level), close the lid, and don't touch it until the solvent front is about 5mm from the top of the plate. Remove the plate, mark the solvent front with a pencil immediately (it evaporates), and let the plate dry before visualization.
