What is silica gel used for TLC?
The silica gel used as adsorbent for HPTLC plates has a mean particle size of approximately 5 µm and, for TLC, 12 µm. The pore diameter of both is mainlyl 60 Å and the surface area is approximately 500 m2/g. The most frequently used thicknesses of thin layer for analytical purposes are approximately 200–250 µm.
Why silica gel G is used in preparation of TLC plates?
The classical binder used is gypsum (G),which is CaSO4•½ H2O, or Plaster of Paris. In most silica gels it is put in at a level of from 10-15% to give good binding to the glass plates. For coating five 20×20 plates, about 30g TLC silica gel to 60ml water is needed.
What should be used to mark the silica gel on the TLC plate?
The silica gel on the TLC plate is impregnated with a fluorescent material that glows under ultraviolet (UV) light. A spot will interfere with the fluorescence and appear as a dark spot on a glowing background. While under the UV light, the spots can be outlined with a pencil to mark their locations.
Is silica a TLC plate coating?
Thin layer chromatography (TLC) is an affinity-based method used to separate compounds in a mixture. In TLC, the stationary phase is a thin adsorbent material layer, usually silica gel or aluminum oxide, coated onto an inert plate surface, typically glass, plastic, or aluminum.
What are the advantages and disadvantages of using TLC technique?
Advantages And Disadvantages Of Thin Layer Chromatography In this technique, fewer types of equipment are used. The separation is done in a very short time as the components elute rapidly. All components of UV light is achievable to visualize. The non-volatile compounds can be separated by this method.
How big is a silica gel TLC plate?
The silica gel TLC plates come in a quantity of 25 size 20×20 cm for thin layer chromatography applications. Glass TLC plate, silica gel coated with flourescent indicator F254. The silica gel TLC plates come in a quantity of 25 size 20×20 cm for thin layer chromatography applications.
When to use silica gel 60 gf254?
Silica gel 60F254 is for fluorescence, i.e. for UV visualization of separation performed over thin-layer. The use of both of these depends on the type of compounds you are expecting in your TLC plate.
What kind of light does silica with f254 absorb?
Silica with F254 has an flourescent material that absorbs light at 254 nm (hence the 254 name) and emits in the visible spectrum.
How are fluorescent indicators used in classical silica TLC?
For UV detection of colorless substances, our classical silica TLC plates are available with two types of inorganic fluorescent indicators: green fluorescing F 254, or blue fluorescing, acid-stable F 254 s. Both indicators fluoresce in UV light at an excitation wavelength of 254 nm.