The difference between adsorption thin layer chromatography and partitioning, ion exchange thin laye

The adsorption chromatography stationary phase is a solid adsorbent that is separated by the difference in the adsorption capacity of each component on the surface of the adsorbent.

The partition chromatography stationary phase is liquid, and the substances are separated by the difference in the partition coefficient or solubility of each component in the two liquid phases.

The ion-exchange chromatography stationary phase is an ion exchanger, which is separated by the different affinities of each component to the ion exchanger.

Summary. They are all the same in principle, but the difference is the force between the mobile phase and the chromatographic agent.

Gel filtration, also known as zeolite chromatography, uses microporous gels to separate components of different molecular weights.

Ion exchange is the use of the electrostatic interaction between the charge of the separated substance and the ionic groups on the chromatography agent.

Compare the differences between gel filtration chromatography and ion exchange chromatography.

In the original dermathetic, they are all the same, the difference is the difference in the force between the mobile phase and the chromatographic agent. Gel filtration, also known as zeolite chromatography, uses microporous gels to separate components of different molecular weights. Ion exchange is the use of the electrostatic interaction between the charge of the separated substance and the ionic groups on the chromatography sensitizer.

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Ion exchange chromatography.

ionexchange

Chromatography, or IEC for short, is one of the methods for separating macromolecules with similar properties from complex mixtures, based on the principle of acidity, alkalinity, polarity, and the difference in the anions and cations carried by the substance. Substances with different charges have different affinities for the ion exchanger on the column, and the ionic strength and pH value of the flush solution can be separated from the chromatography column in turn.

Ion exchange chromatography is broadly divided into 5 steps:

1.Ions diffuse to the surface of the resin.

2.Ions diffuse through the resin to the exchange site.

3.Ion exchange at the exchange site; The more charged the molecule is exchanged, the tighter it binds to the resin and the less likely it is to be replaced by other ions.

4.The exchanged ions diffuse to the surface of the resin.

5.The rinse fluid passes through and the exchanged ions diffuse into the external solution.

The exchange reaction of ion exchange resin is reversible, following the law of chemical equilibrium, when the quantitative mixture passes through the column, the ions are continuously exchanged, the concentration gradually decreases, and almost all of them can be adsorbed on the resin; During the rinsing process, the new exchange solution is added continuously, so it moves in the direction of the positive reaction, so that the ions on the resin can be washed off.

If the substance being purified is an amino acid molecule, then the net charge on the molecule depends on the isoelectric point of the amino acid and the pH of the solution, so when the pH of the solution

The value is lower, the amino acid molecule is positively charged, and it will bind to a strongly acidic cation exchange resin;As the pH of the buffer passing, the amino acids will gradually lose their positive charge, weaken their binding force, and finally be washed off. Due to the different isoelectric points of different amino acids, these amino acids will be washed out in turn, and the first to be washed out are acidic amino acids, such as apartic

acid and glutamic

acid (at about pH3 4), followed by neutral amino acids such as glycine and alanine. Basic amino acids such as arginine and lysine are still positively charged in buffers with high pH, so these only appear at about pH 10 11.

Ion exchange chromatography principle: It is a chromatography method that uses the ion exchanger as the stationary phase and separates the ionizer according to the difference in the binding force of the component separator in the mobile phase and the equilibrium ions on the exchanger during the reversible exchange.

It is a chromatography method that uses the ion exchanger as the stationary phase and separates the separators according to the difference in the binding force of the group separator in the mobile phase and the equilibrium ions on the exchanger during the reversible exchange.

The principle of ion exchange chromatography is as follows:

Ion-exchange chromatography (IEC) is one of the most widely used methods for the purification of biological macromolecules.

Ion exchange chromatography is a method of separating proteins according to the different charges of the protein under a certain pH condition. Ion exchangers commonly used for protein separation are weakly acidic carboxymethyl fibers.

Ion exchange chromatography is a method of separating proteins according to the different charges of proteins under certain pH conditions. Ion exchangers commonly used for protein separation are weakly acidic carboxymethyl fibers.

Applications: Ion exchange chromatography has been widely used in various disciplines. It is mainly used in biochemical and clinical biochemical tests to separate amino acids, peptides and proteins, and can also be used to separate nucleic acids, nucleotides and other charged biomolecules.

Extended content: Mixed ion exchange column (mixed bed): The mixed bed is filled with positive and anion resins in a certain proportion (generally 1:

2, so that the yang and yin resins reach the exchange end point at the same time and regenerate at the same time) loaded into the mixing column, in fact, it is combined into H+ and OH- in the water to immediately generate water molecules (H2O) with a small degree of ionization, and there is almost no reverse exchange phenomenon produced when the yang bed or yin bed is exchanged, so the exchange reaction can be carried out very thoroughly, so the effluent quality of the mixed bed is better than the water quality that can be achieved by the double bed composed of the yang and yin beds in series, and the finished water with a fairly high purity can be prepared.

Ion exchange chromatography is a method of separation and purification based on the difference in charge of proteins. The chargeability of a protein is determined by the charged amino acids in the protein polypeptide. Since the electrical properties of amino acids in proteins depend on the pH of the medium, the chargeability of the protein also depends on the pH of the medium.

When the pH is low, the negative group is neutralized, while the positive group is numerous; At a higher pH, the electrical properties of the protein are opposite to those at a low pH. When the pH of the protein equalizes the positive and negative charges of the protein, the pH at this time is called the isoelectric point. The exchanger used in ion exchange chromatography is made by introducing positive or negative ion groups through chemical reactions such as esterification and oxidation, and can be exchanged and adsorbed with oppositely charged proteins.

Exchangers with cationic groups can displace and adsorb negatively charged substances, called anion exchangers, such as DEAE-cellulose resins; Otherwise, it is called a cation exchanger, such as CM-cellulose resin. Different proteins have different isoelectric points, and the types and amounts of charge carried by dissociation under certain conditions are different, so they can be exchanged and adsorbed with different ion exchangers with different affinities. When the ionic groups in the buffer compete with the proteins bound to the ion exchanger, the protein molecules with low affinity are first desorpted and elute, while the proteins with high affinity are later desorbed and elute.

Therefore, by increasing the ionic strength of the buffer or changing the pH, the adsorption of proteins can be changed, so that proteins with different affinities can be separated.

Ion exchange chromatography is a chromatography method that uses an ion exchanger (a substance with ion exchange properties) as a stationary phase, and uses its reversible exchange properties with ion energy in the mobile phase to separate ionic compounds. That is, the reaction process of the exchange of functional groups between ions in solution and ion exchanger. Those with small charge and small affinity are eluted first, and those with more power and large affinity are eluted off.

1.Thin layer chromatography, also known as thin layer chromatography, is a chromatography separation technology that uses the support coated on the support plate as the stationary phase and a suitable solvent as the mobile phase to separate, identify and quantify the mixed samples, which is a particularly effective chromatography method for the rapid separation of fatty acids, steroids, amino acids, nucleotides, alkaloids and other substances.

2.Basic principle: adsorption thin layer chromatography separation method, which uses the different adsorption capacity of each component to the same adsorbent, so that in the process of mobile phase flowing through the stationary phase, continuous adsorption, desorption, re-adsorption, re-adsorption, re-adsorption, so as to achieve the purpose of separation of each component.

3.Thin-layer chromatography can be divided into thin-layer adsorption chromatography, thin-layer partition chromatography, thin-layer ion exchange chromatography, thin-layer gel chromatography, etc., according to the different supports as stationary phases.

4.The reason why material molecules can stay on the surface of the solid is because the attraction of the molecules on the surface of the solid and the molecules inside the solid is not equal, the adsorption process is reversible, and the adsorbate can be desorbed out under certain conditions, and the adsorption chromatography process is a dynamic equilibrium process that continuously produces equilibrium and imbalance, adsorption and desorption.