Silica RP18 Chromatography Reverse Phase Column Chromatography Silica Gel C18

• Customization: Available
• CAS No.: Msio2.Nh2o
• Formula: Msio2.Nh2o
• Model NO.: C
• EINECS: 7631-86-9
• Shape: Pellet
• Drying Method: Static Drying
• Kind: Silica-Gel Desiccant
• Sorbent: Silica Gel
• Desiccant: Physical Desiccant
• Packing: Bottle/Bags
• Transport Package: Bags
• Specification: 60-100/100-200/200-300/300-400
• Trademark: HENGZE
• Origin: Qingdao
• HS Code: 28112210
• Production Capacity: 50tons/Month

Product Description

Silica gel column chromatography
Chromatography is also known as chromatography. Chromatography is a distribution method based on the mechanism of distribution equilibrium.
The chromatographic system consists of two phases, a stationary phase and a mobile phase. When the two phases move relative to each other, they repeatedly use the difference in the distribution equilibrium of the components contained in the mixture, and finally achieve the purpose of separating from each other.
Chromatography can be divided into
1. Column chromatography
2. Plate chromatography
3 . Rod chromatography
The most commonly used in the laboratory is column chromatography (often referred to as over the column) and thin-layer chromatography and the application of their co-ordination
The stationary phase for column chromatography is usually silica gel, alumina, polyamide, activated carbon.
1,Principle of adsorption chromatography
Under certain conditions, the silica gel and the substance to be separated between the action, this action is mainly two kinds of physical and chemical action. Physical action from the surface of the silica gel and solute molecules between the van der Waals force: chemical action is mainly the silica gel surface of the silicon hydroxyl and to be separated from the substance between the hydrogen bonding.
2, the operation of silica gel preparation is generally used 200-00 mesh and 300-400 days.5 top instrumentation to prepare a glass chromatographic column, an iron stand, beakers, conical flasks, a larger diameter of the diameter of the glass funnel, a glass rod and so on.
3, loading column adsorbent addition
Dry method: use the column with a sand core plate (or add a little cotton or glass wool at the lower end of the ordinary column), open the lower mouth, and then the adsorbent through the funnel slowly added to the column, and at the same time, gently knocking the column, so that the adsorbent loose and tight consistent.
Wet method: Add the adsorbent to the appropriate amount of eluent initially used in the chromatography, make a paste, open the column with a sand core plate (or add a little cotton or glass wool at the lower end of the ordinary chromatographic column in advance) and then slowly pour the prepared paste into the column. Take care that the whole procedure is carried out slowly, do not press air bubbles into the adsorbent, and always keep the solvent at the upper end of the adsorbent, do not run dry. Finally, let the adsorbent sink naturally, and when the eluent just covers the plane of the adsorbent, close the lower port piston tightly
Sample addition
Dry method: when the separated substances are difficult to dissolve in the initial use of the eluent, you can choose a solvent that has a large solubility and a low boiling point, dissolve the sample in as little as possible in the solvent, add the solution to an appropriate amount of adsorbent or add the adsorbent to the solution, mixing well to evaporate the solvent, grinding to make a loose and uniform powder, gently sprinkled in the column on top of the adsorbent, and then sprinkled a layer of fine sand or adsorbent used to protect it. Note that when loading the column in dry method, the piston of the column should be in the open state.
Wet method: dissolve the separated sample in a small amount of chromatography initially used in the non-degreasing agent, carefully added to the upper layer of the adsorbent, pay attention to the top of the sample, the top of the column must be made to just cover the adsorbent plane of the eluent and keep the surface of the adsorbent for a horizontal plane, open the lower port, to be the solution flowed just in time with the adsorbent on the upper surface of the same time, add a small amount of eluent (a small amount of multiple times) drenching the wall of the column, close the column at the lower end of the piston.
The target product was obtained by combining the fractions with the same Rf value according to the results of the thin-layer detection, and then spinning the combined fractions using a rotary evaporator.
Washing of the chromatographic column
Usually the silica gel in the silica gel separation column is for one-time use, but the column contains rinse solvent after use, so it is difficult to pour out. To remove the silica gel: 1. Leave the column for a period of time and let the solvent evaporate naturally, then pour out the silica gel. (Disadvantages of time-consuming, pollution) 2, with a wooden rod or plastic rod will be a section of silica gel out 3, with a vacuum pump will be the column of the remaining solvent decompression pumped out in the column and the vacuum pump to add a cold trap between the column (Advantages: fast, non-polluting, silica gel can be quickly dried).
Chromatographic column selection
Columns can be divided into: decompression columns, pressurised columns, atmospheric columns.
1 Decompression column: reduce the amount of silica gel, but a large amount of air through the silica gel will make the solvent volatilisation, as well as some of the more decomposition-prone things may not be obtained, and must be used at the same time the pump pumping (noisy, long)
2 pressurised column: similar to the atmospheric pressure column, additional pressure to make the eluent go faster (compressed air to provide pressure) in the separation of easily decomposed samples when the pressure should not be too large (solvent go too fast will reduce the separation effect) 3 atmospheric pressure column: the column is not suitable for the separation of the solvent.
Separation effect)3 atmospheric pressure column: the advantage is that the separation efficiency is much higher than the classic chemical separation of the top of the large collar, compared with other chromatographic methods, do not need expensive equipment, easy to replace the mobile phase and adsorbent, less material consumption, low cost, suitable for the separation of a wide range of samples from the sampling volume from grams to micrograms of various samples, and therefore in the chemical laboratory is widely used.