What is the difference between silicone H plate and silicone G plate

Silicone G is a model of silicone, according to our current use of more silicone H and GF254 and so on. Silicone board is mainly used for thin layer chromatography, and now there are different types of silica gel paved silicone boards on the market, and silicone G board is only one of them. The main difference between different types of silica gel is the difference in the gypsum content, which is the macro performance.

1. Silica gel G: chemical formula XSIO2·YH2O. Clear or milky granular solids.

It has an open porous structure, strong adsorption, can adsorb a variety of substances, and has a moisture absorption of about 40%. If cobalt chloride is added, it will be blue when it dries and red when absorbed. Recyclable and reusable.

2. Silica gel H: silica without adhesive (CMC-NA). Silica gel H is the stationary phase or carrier coating of two silica gel plates commonly used in thin layer chromatography in analytical chemistry.

3. The silica gel-G board is made of calcined gypsum as the adhesive, and the mechanical strength of the board is poor and easy to fall off. Column chromatography generally uses silica gel H, and the mesh number is 300, etc. Thin layer chromatography is the process of coating a suitable stationary phase on a glass plate, plastic or aluminum substrate to form a uniform thin layer.

After spotting, it is compared with the chromatogram obtained by the same method with the appropriate reference substance, which is used for drug identification, impurity inspection or content determination.

Silicone G plates are adhesive-added, while silicone H-plates are non-adhesive.

G refers to gypsum, which is used as a binder, H is without binder, and F254 refers to the addition of a substance that can excite fluorescence at 254 nm. How to choose, according to your situation to see it Generally, when using GF254, when doing the extraction and separation of traditional Chinese medicine, use more 254 plates, things with benzene rings are absorbed at 254, and the points are easier to observe I don't use much G plates, I think things that may have fluorescence are better, H plates are used less, without gypsum binders.

Silica H does not contain binders (for column chromatography packing columns).

Silica gel G contains calcined gypsum binder (for thin layer chromatography plates).

Silica gel GF254 contains calcined gypsum and fluorescent agent (used for thin-layer chromatography plates and needs to observe fluorescence under 254 nm ultraviolet light after separation).

Silica gel can be divided into silica gel H (without adhesive), silica gel G (with adhesive) and silica gel HF (containing fluorescent substances).

Silica gel, also known as silicate gel, is a granular porous silica hydrate, which is an amorphous substance, transparent or milky white in appearance, prepared by washing and drying after adding acid to sodium silicate, with stable chemical properties and non-combustion. Silica gel is a highly active adsorption material, mainly used as a desiccant and an adsorbent in column chromatography and thin layer chromatography, generally speaking, it can be divided into two categories: organic silica gel and inorganic silica gel.

1. The ingredients are different.

Silica H is a binder-free (CMC-Na) silica (usually adsorbed with water);

Silica gel G is a binder-containing silica with the chemical formula XSIO 2·YH 2O.

2. Different uses.

Silicone G is used for boarding, which has strong hardness and can be written on it with a pencil;

Typically 100-200 mesh silica H is used for column chromatography, and finer silica H is used for thin layer chromatography.

Silicone H does not contain adhesives.

Silica gel G contains calcined gypsum binder.

If you can't buy it ready-made, you can configure a 1% sodium hydroxide solution as a wetting agent for silica gel G, and then spread it yourself.

F254 fluoresces in the 254 nm band, which can be used to test substances that absorb ultraviolet light, and there is also an F365, which is similar to the above, but in a different band.

If I'm not mistaken, silicone G should be silicone containing an adhesive (usually gypsum), while silicone H is a silicone that does not contain an adhesive.

Silica gel is classified mainly according to its composition and particle diameter.