Chromatography Definition

Chromatography is an essential biophysical technique for separating, identifying, and purifying mixture components for qualitative and quantitative investigation.

Different chromatographic techniques exploit differences in size, binding affinities, charge, as well as other characteristics to separate items.
It is a powerful separation technique used in a variety of scientific disciplines, and it is occasionally the only means to separate parts from challenging combinations.
Chromatography is a highly helpful method because it allows components of a mixture to be separated based on their nature, structure, size, as well as other properties.
Chromatography, in general, is built on the notion that components of a composition are isolated while the composition, which has been introduced to a mobile phase, is moved via a stationary phase, which is generally a solid surface and results in certain components of the mixture being attached to it. The mobile phase is completed concurrently with the other phases.
There are therefore two key elements shared by all chromatography procedures.

What is a stationary phase?

The stationary phase in chromatography is a liquid or solid particle attached to a glass or metal surface which specifically takes the mixture’s constituent parts.

Since this phase is stationary while the other phase is in motion, it is referred to as stationary.
The majority of materials used as stationary phases have pores, which enable components to adhere during chromatography.
A stationary phase must be chosen based on the chromatographic method being used and the characteristics of the components that need to be separated.
The stationary phase can be made of gel beads, thin uniform paper, silica, glass, some gases, or even liquid components, depending on the type of chromatography being used.

What is the mobile phase?

The mobile phase is the liquid or gaseous part of the chromatographic system through which the constituents of the combination are isolated at varied speeds by adsorbing to the stationary phase.

The mobile phase is the solvent which moves the combination through the stationary phase.
In the chromatographic system, a phase is said to be mobile if it is going down the system, whereas the other phase is remaining static.
Depending on the kind of chromatography being employed and the characteristics of the components that need to be separated, the materials for mobile phases are selected.
In many chromatographic procedures, the mobile phase is frequently used to be alcohol, water, acetic acid, acetone, or certain gases.

Types of Chromatography

1.Affinity chromatography

According to their affinity for the system’s stationary phase, a mixture’s constituents are isolated using the separation process known as affinity chromatography.

Principle of Affinity chromatography

Based on the hypothesis that elements having an attraction towards the stationary phase adhere to the stationary phase, separating constituents of a mixture occurs. This chromatography method was developed. Other substances are eluted with the mobile phase, on the other hand.
The substrate/ligand is bound to the stationary phase, exposing the reactive areas for component binding.
When the mixture passes through the mobile phase, the components with substrate binding sites now connect towards the bottom of the stationary phase, while the other components are washed off with the mobile phase.
The associated components of the stationary phase are then liberated by adjusting the pH, ionic strength, or other variables.

Steps of Affinity chromatography

The substrate/ligand with the spacer arm is bonded to the solid support, such as agarose or cellulose, which has been used to construct the column.
A steady stream of the mixture-containing mobile phase is added to the column.
The circumstances which promote this isolation are changed when the operation is completed, allowing the ligand-molecule complex to be isolated from the other components of the mixture and eluted from the stationary phase.

Uses of Affinity chromatography

The standard separation method for enzymes and other proteins is affinity chromatography.
The in vitro antigen-antibody responses also use this theory.
This method is employed to separate components from mixtures as well as to purge them of contaminants.
Affinity chromatography can be used to detect mutations as well as nucleotide polymorphisms in nucleic acids.

Examples of Affinity chromatography

Using p-aminophenyl-1-thio-D-galactopyranosyl agarose as the affinity matrix, coli-galactosidase was isolated from a variety of proteins.
The purging of 2-macroglobulin and extra albumin from serum albumin

2.Anion exchange chromatography

Negatively charged molecules are separated via anion exchange chromatography through a stationary phase that is positively charged, such as ion-exchange resin.

Principle of Anion exchange chromatography

This method is based on the idea that positively charged resin and negatively charged analyte are attracted to one another. Here, negatively charged molecules are eliminated by the exchange of positively charged ions.
The components in the mixture with negative charges will bond to the stationary phase, which is first coated with positive charges.
The positively charged resin is subsequently dislodged and the negatively charged elements are bonded by an anion exchange resin which has a higher affinity for them.
The complex made up of the components of the anion exchange resin is then eliminated by using various buffers.

Steps of Anion exchange chromatography

The stationary phase consists of a positively charged resin column.
The mixture of charged particles is then directed into the column, where resins that are positively and negatively charged interact.
The positively charged resin is now replaced by the negatively charged molecules, which bind to the anion exchange resin and move it through the column.
An appropriate buffer is now added to the column in order to isolate the complex of anion exchange resins as well as the charged molecules.

Uses of Anion exchange chromatography

Anion exchange chromatography is used to separate proteins and amino acids from their mixtures.
Negatively charged nucleic acids may be isolated, which facilitates further nucleic acid analysis.
This process may also be applied to the hydroxyl ion exchange in water treatment.
Metal separation can be accomplished using anion exchange resins because these materials frequently include complexes that are negatively charged and bind to the anion exchangers.

Examples of Anion exchange chromatography

the process of separating nucleic acids from a mixture that is produced following cell death.
the process of separating proteins from a blood serum-derived crude mixture.

3.Cation exchange chromatography

Positively charged molecules are separated via anion exchange chromatography by interacting with a negatively charged stationary phase, such as ion-exchange resin.

Principle of Cation exchange chromatography

This approach is predicated on the notion that positively charged analytes and negatively charged resin would be attracted to one another. Here, positively charged molecules are eliminated by the exchange of negatively charged ions.
The components of the combination with positive charges are initially covered with negative charges in the stationary phase, where they will bond.
A cation exchange resin with a higher affinity for positively charged components then binds them, dislodging the negatively charged resin.
The complex made up of the components of the cation exchange resin is subsequently eliminated by using various buffers.

Steps of Cation exchange chromatography

A column of negatively charged resin serves as the stationary phase.
After passing the combination of charged particles down the column, positively charged molecules attach to the negatively charged resins.
The negatively charged resin is now displaced by the positively charged molecules, which bind to the cation exchange resin and cause it to move through the column.
The appropriate buffer is now added to the column in order to isolate the complex of cation exchange resins as well as the charged molecules.

Uses of Cation exchange chromatography

Analyzing the byproducts of the breakdown of nucleic acids is done using cation exchange chromatography.

The metal ions themselves may attach to the negatively charged resins when metals are being separated in order to remove the negatively charged complexes.

Cation exchange chromatography helps to purify water by transferring the positively charged ions to hydrogen ions.

Inorganic molecules and rocks are both analysed using it.

Examples of Cation exchange chromatography

the process of separating positively charged lanthanoid ions from the crust of the earth.
the analysis of the presence of calcium ions to determine the total amount of salts dissolved in natural waterways.

4.Column chromatography

In column chromatography, based on how differently the components stick to the stationary phase, which causes them to flow at different speeds when passed through a column, the constituents in a mixture are separated.

It employs a solid-liquid chromatography technique where the stationary phase is a solid and the mobile phase is a liquid or gas.

Principle of Column chromatography

This process is based on the idea of differential adsorption, where different molecules in a mixture have varied affinities for the absorbent that is placed on the stationary phase.
Higher affinity molecules stay adsorbent for a longer period of time, slowing down their passage down the column.
The molecules may be divided into distinct fractions because the molecules with less affinity move more quickly.
In this scenario, the stationary phase, often referred to as the absorbent in column chromatography, is a hard substance (typically silica), while the mobile phase is a liquid that allows molecules to move smoothly along the column.

Steps of Column chromatography

The column is created by coating a glass tube with a homogeneous, thin layer of stationary phase after it has been cured (cellulose, silica).
The mixture is then poured into the mobile phase to create the sample. The sample enters the column from the top and is allowed to flow through the column while being affected by gravity.
By using an elution approach, the molecules coupled to the column are separated, either using a solution with the same polarity (isocratic technique) or various samples with different polarities (gradient technique).
Following separation, the molecules can be further studied for a number of purposes.

Uses of Column chromatography

To separate things, column chromatography is widely employed to separate contaminants from diverse biological mixtures and purify them.
Additionally, active compounds and metabolites from diverse substances may be isolated using this method.
More and more labs are using column chromatography to find medicines in raw extracts.

Examples of Column chromatography

extraction of pesticides from animal-sourced solid food samples that comprise lipids, waxes, and colours.
To treat type 1 and type 2 diabetics, Pramlintide, a peptide hormone analogue of Amylin, was created.
bioactive glycolipids that are purified and have antiviral action against HSV-1 (Herpes Virus).

5.Flash chromatography

A separation method called flash chromatography uses smaller gel particle sizes as the stationary phase and pressured gas to move the solvent through the column.

Principle of Flash chromatography

Similar to column chromatography, which separates the components based on their differential adsorption on the stationary phase, flash chromatography works on a similar premise.
A pressurised gas is used to pass the applied sample, speeding up and improving the procedure.
According to their affinity, molecules attach to the stationary phase, and the remaining solvent is rinsed out by injecting pressurised gas to speed up the process.
Here, the mobile phase, the elution solution, and an extra pressurised gas are all liquids while the stationary phase is solid.

Steps of Flash chromatography

After the stationary phase has hardened, a glass tube is coated with a uniform, thin layer to form the column (cellulose, silica). Cotton wool is placed at the bottom and top of the column to prevent the gel from leaking out.
The mixture is then poured into the mobile phase to create the sample.The sample is fed into the column from the top and then passed at a constant rate using a pumped sample.
Either a solution with the same polarity is used (isocratic approach) or several samples with varying polarities are used to elute the molecules attached to the column (gradient technique).
A constant minimum pressure is used to apply the elution solvent in order to transport the solute down the column.
Following separation, the molecules can be further studied for a number of purposes.

Uses of Flash chromatography

As a quicker and more effective way of separating the constituents of various mixes, flash chromatography is employed.
It is used to clean out contaminants from unprocessed natural and manufactured mixed extracts.

6.Gas chromatography

With the use of the separation technique known as gas chromatography, Because of their attraction for the stationary phase, molecules are sorted based on their retention durations.
The sample, which is vaporised at the injection location, is either a liquid or a gas.

Principle of Gas chromatography

The principle that compounds having a stronger attraction to the stationary phase possess a longer retention time since they require longer time to exit the column is the basis of gas chromatography.
The components having a stronger attraction for the stationary phase, however, possess a shorter retention time while they migrate through the mobile phase.
The sample is moved through the column by a gas called the mobile phase, which is frequently helium.
Once the sample has been injected, it is converted to the vapour stage, and the retention time is then measured by passing the sample through a detector.
At different times, the components emerge from the stationary phase, and each one is collected.

Steps of Gas chromatography

The sample is vaporised after being introduced into the column, turning it into a gas. The vaporised component then joins with the mobile phase to pass through the remaining portion of the column.
The molecules are isolated based on their attractions to the stationary phase once the stationary phase is introduced in the column.
Due to variations in how long each component is maintained in the column, the mixture’s components arrive at the detector at different times.

Uses of Gas chromatography

Calculating the concentration of various compounds in various samples is done using this method.
Oil spills, air pollution, and other samples are all analysed using this.
The identification and measurement of numerous biological substances discovered at the crime scene may also be done using gas chromatography in forensic science.

Examples of Gas chromatography

finding performance-enhancing drugs in an athlete’s urine
The identification and measurement of solid medications in water and soil samples

7.Gel filtration chromatography/ Gel permeation chromatography, size exclusion chromatography/ Molecular sieve chromatography

Gel-filtration chromatography is a form of partition chromatography utilized to isolate molecules with different molecular sizes.
This technique has also been referred to by a variety of other names, including gel-permeation, gel-exclusion, size-exclusion, as well as molecular-sieve chromatography.

Principle

According to their respective sizes, there are two phases for molecules: the mobile phase and the stationary phase.
A porous polymer matrix with pores of a certain size makes up the stationary phase.
The mobile phase fills the pores of the stationary phase when it is injected into the sample.
If the molecules are the right size to fit within the pores, they partially or completely stay there.
However, bigger molecules are prevented from entering the pores and are instead transported out of the column by the mobile phase.
Gel filtration chromatography is the name of the procedure when the mobile phase is utilised in an aqueous solution.
If an organic solvent is used as the mobile phase, the process is termed gel permeation chromatography.

Steps

Semi-permeable, porous polymer gel beads with a well specified range of pore diameters are used to fill the column.
The sample and mobile phase are then combined before being injected into the column from its top.
Either a solution with a similar polarity is utilised (isocratic approach) or several samples with varying polarities are utilised to elute the molecules attached to the column (gradient technique).
You can choose elution conditions (pH, necessary ions, cofactors, protease inhibitors, etc.) that will complement the needs of the target molecule.

Uses

The ability to accomplish separation in conditions carefully created to preserve the stability and activity of the target molecule without sacrificing resolution is one of the key benefits of gel-filtration chromatography.
Since there is no molecule-matrix binding stage, delicate molecules are not unnecessarily harmed, making gel-filtration separations often result in high activity recoveries.
Because of its distinctive mechanism of separation, protein separation has been accomplished with success using gel-filtration chromatography and peptides from a variety of sources.
Different nucleic acid species, including DNA, RNA, and tRNA, as well as their component bases, adenine, guanine, thymine, cytosine, and uracil, have been separated using gel-filtration chromatography.

Examples

For the isolation of recombinant human granulocyte colony-stimulating factor (rhG-CSF) from inclusion bodies, use high-yield urea-gradient size-exclusion chromatography.
employing gel columns made of both acrylamide and dextran to separate the lysozyme from hen eggs.

8.High-performance liquid chromatography (HPLC)

The components of a mixture are isolated using high-performance liquid chromatography, a refined type of column chromatography, based on their attraction to the stationary phase.

Fundamentals of HPLC

The principle of differential adsorption, in which different molecules in a mixture contact the absorbent on the stationary phase to varying degrees, is the foundation of this technique.
Higher affinity molecules remain adsorbent for longer, delaying the column’s descent of those molecules.
The molecules may be divided into distinct fractions because the molecules with less affinity move more quickly.
This procedure differs slightly from column chromatography in that the solvent is pressed under strong pressures of up to 400 atmospheres in this instance, rather than being allowed to drop naturally.

Steps of HPLC

The column is created by coating a glass tube with a homogeneous, thin layer of stationary phase after it has been cured (cellulose, silica).
The mixture is then poured into the mobile phase to create the sample. A high-pressure pump is used to pass the sample at a steady pace once it is inserted into the column from the top.
The mobile phase then descends to a detector that looks for molecules at a certain wavelength of absorbance.
The separated molecules can then be examined further for a variety of reasons.

Uses of HPLC

High-performance liquid chromatography is used to analyse pollutants detected in environmental samples.
It is done to keep industrial production diverse, its quality and product purity under control.
Additionally, various biological substances, including proteins and nucleic acids, may be separated using this method.
The procedure is quicker and more efficient because of the rapid pace of this technology.

Example of HPLC

A technique called high-performance liquid chromatography has been used to evaluate how well certain antibodies protect against illnesses like Ebola.

9.Hydrophobic interaction chromatography

interaction between hydrophobes The separation method known as chromatography divides molecules according to how hydrophobic they are.

Principle of Hydrophobic interaction chromatography

The hydrophobic interaction theory: the interaction between two molecules with hydrophobic groups is the foundation of chromatography.
The stationary phase in this instance is a solid support that has hydrophobic and hydrophilic groups added to it.
The solvent molecules with hydrophobic regions interact with the hydrophobic groups, separating them from the molecules with hydrophilic groups.
The interaction is subsequently inverted, leading to the isolation of the hydrophobic molecules from the stationary phase by applying an elution solution with a decreasing salt gradient.

Steps of Hydrophobic interaction chromatography

The column is made by covering a glass tube with a solid support, such as silica gel, then attaching hydrophobic groups, such as phenyl and octyl butyl, to it.
The mixture is added to the mobile phase to create the sample.
The sample is then fed into the column from the top following that.
The hydrophobic groups of the stationary phase’s hydrophobic molecules interact with the molecules having hydrophobic groups. The molecules lacking these groups, on the other hand, move with the mobile phase to leave the column.
The attached molecules are subsequently extracted from the stationary phase using a specific elution solution that has a decreasing salt gradient.

Uses of Hydrophobic interaction chromatography

The interaction of hydrophobes Chromatography is essential for the isolation of proteins containing hydrophobic groups.
As it causes the least amount of denaturation activity, this technique is more suited than other ways.
This technique can be used. It is similar to the separation of other organic molecules having hydrophobic groups.
This makes it possible to separate biological molecules that are hydrophilic from those that are hydrophobic.

An Example of Hydrophobic Interaction Chromatography

the exclusion of crude extracts from plant proteins.

10.Ion exchange chromatography

In ion exchange chromatography, charged molecules are separated from one another by interacting with an oppositely charged stationary phase, such as ion-exchange resin.

Principle of Ion exchange chromatography

This method is based on the idea that charged resin will attract an analyte that is negatively charged. In order to remove the charged molecules, an interchange of negatively and positively charged ions occurs.

The components of the mixture with opposite charges will bond when the stationary phase is initially covered with specific charges.

The charged components are then bound by a cation or anion exchange resin that has a stronger affinity for them, replacing the oppositely charged resin.

The complex of the cation or anion exchange resin is subsequently eliminated using various buffers.

Steps of Ion exchange chromatography

The stationary phase is a column filled with charged resin that may be positively or negatively charged.
The charged molecules then bond to the resins that have opposing charges when the mixture containing the charged particles is moved down the column.
If a cation exchange resin is used, the positively charged molecules now bind to the cation exchange resin, replacing the negatively charged resin.
Similar to this, when using an anion exchange resin, the positively charged resin is replaced with negatively charged molecules that bond to the anion exchange resin.
In order to separate the complex of charged exchange resins and the charged molecules, the proper buffer is now added to the column.

Uses of Ion exchange chromatography

In the process of purifying water, ion exchange chromatography replaces positively charged ions with hydrogen ions and negatively charged ions with hydroxyl ions.
This technique also functions well for the analysis of the byproducts of nucleic acid hydrolysis.
Ion-exchange chromatography also makes it easier to separate metals and other inorganic substances.

Examples of Ion exchange chromatography

the process of separating positively charged lanthanoid ions from the crust of the earth.
the process of separating proteins from a blood serum-derived crude mixture.

11.Liquid chromatography

Liquid chromatography is a method of separation where the mobile phase is a liquid, and the separation can occur on a simple surface or in a column.

Principle of Liquid chromatography

The concept underlying the molecules’ affinity for the mobile phase serves as the foundation for liquid chromatography.
The molecules travel with the mobile phase and exit the column more quickly if the components to be separated have a higher affinity for it.
The molecules travel slowly and exit the column later, however, if the components interact with the mobile phase to a lesser extent.
The two molecules will thus travel through the stationary phase at different rates if the two molecules in a mixture have different polarities and the mobile phase is of a different polarity.

Steps of Liquid chromatography

The stationary phase (cellulose or silica) is put on the solid support to create the column or paper.
The liquid mobile phase, which includes the sample in it, is then injected into the chromatographic apparatus.
The mobile phase passes through the stationary phase before exiting the column or the edge of the paper.
To remove the molecules from the stationary phase, the system is exposed to an elution solution.

Uses of Liquid chromatography

A coloured solution may be separated using liquid chromatography, and the separated coloured solution forms two distinct bands.
Due to its ease of use and lower cost, this approach might also be preferred to others.
It may be used to separate solid molecules from liquid ones that cannot dissolve in water.

Examples of Liquid chromatography

In the study of biological molecules, a modified version of liquid chromatography known as high-performance liquid chromatography is employed.

12.Paper chromatography

Paper chromatography is a method of separation in which the separation is carried out on a particular type of paper.

Principle of Paper chromatography

Two distinct forms of paper chromatography are based on two distinct ideas.
The first type of chromatography uses paper adsorption and is based on the different levels of contact that exist between the molecules and the stationary phase.
Higher affinity molecules stay adsorbent for a longer period of time, slowing down their passage down the column.
The molecules may be divided into distinct fractions because the molecules with less affinity move more quickly.
Paper partition chromatography is the second kind of paper chromatography. It is based on the idea that the molecules travelling with the mobile phase use the moisture on the cellulose paper as a stationary phase to stop.
Thus, the degree to which the molecules adsorb to the stationary phase determines how the molecules are separated.
When separating molecules using paper chromatography, a further notion of “retention factor” is used.
The ratio of the molecule’s travel distance to the mobile phase’s travel distance yields the retention value for a given molecule.
Different compounds can be distinguished from one another using their retention values.

Steps of Paper chromatography

Exceptionally high-quality cellulosic paper is chosen as the stationary phase.
As the mobile phase, several mixtures of organic and inorganic solvents are used.
At the baseline of the paper, 2–200 litres of the sample solution are injected, and the paper is then left to air dry.
The sample-loaded paper is then slowly lowered to a height of no more than one centimetre in the mobile phase.
The paper is removed when the mobile phase is close to the edge of the paper.
The separated components are recognised using various methods, and the retention factor is determined.

Uses of Paper chromatography

To determine the purity of various medicinal goods, paper chromatography is used.
Additionally, it may be used to identify contamination in a variety of samples, including food and drinks.
The removal of contaminants from a variety of industrial items may also be done using this technique.
Paper chromatography is another method used in chemistry labs to analyse reaction mixtures.

Examples of Paper chromatography

The separation of ink mixes or other coloured liquids using paper chromatography.

13.Reverse-phase chromatography

Reverse-phase chromatography is a type of liquid chromatography in which the liquid mobile phase and stationary phase interact hydrophobically to separate molecules.

Principle of Reverse-phase chromatography

The interaction between two molecules with hydrophobic groups is the foundation of the reverse phase chromatography method.
The stationary phase in this instance is a solid support that has hydrophobic and hydrophilic groups added to it.
The hydrophobic groups interact with the solvent molecules with hydrophobic regions, isolating them from the molecules with hydrophilic groups.
By administering an elution solution with a decreasing salt gradient, the contact is then reversed, resulting in the separation of the hydrophobic molecules from the stationary phase.

Steps of Reverse-phase chromatography

The column is made by covering a glass tube with a solid support, such as silica gel, then attaching hydrophobic groups, such as phenyl and octyl butyl, to it.

The combination is added to the mobile phase of organic and inorganic solvents to prepare the sample.

After that, the sample is injected into the column from the top.

The hydrophobic groups of the stationary phase’s hydrophobic molecules interact with the molecules having hydrophobic groups. The molecules lacking these groups, on the other hand, migrate out of the column with the mobile phase.

The attached molecules are subsequently extracted from the stationary phase using a specific elution solution that has a decreasing salt gradient.

Uses of Reverse-phase chromatography

For the separation of biomolecules, reverse chromatography is increasingly employed in conjunction with high-performance liquid chromatography.
This is also used in the research of metabolite and active molecule analysis.
It may also be used to clean up different environmental samples that include contaminants.

Examples of Reverse-phase chromatography

Reverse phase chromatography is an example where this method is used to separate proteins from their mixtures, as in the case of hydrophobic interaction chromatography.

14.Thin-layer chromatography (TLC)

The separation method known as thin-layer chromatography uses a liquid mobile phase and a stationary phase that is deposited as a thin layer on a solid support plate.

Principle of Thin-Layer Chromatography (TLC)

This method of chromatography is based on the idea that when a component with an affinity for the stationary phase attaches to the stationary phase, the mixture’s components are separated. Other substances, on the other hand, are eluted by the mobile phase.
The reactive sites for component binding are made visible because the substrate and ligand are attached to the stationary phase.
The components having substrate binding sites now bond to the substrate on the stationary phase when the mixture is passed through the mobile phase, and the remaining components are rinsed out with the mobile phase.
Following separation, the molecules appear as dots throughout the stationary phase, each in a separate place.
Many different strategies are used to find molecules.

Steps of Thin-layer chromatography (TLC)

On the firm support (glass, a thin plate, or aluminium foil), the stationary phase is evenly placed and dried.

About a centimetre above the plate’s edge, the sample is injected as spots on the stationary phase.

After that, the sample-loaded plate is gently dipped into the mobile phase to a maximum depth of 1 cm.

The plate is removed when the mobile phase is close to the plate’s edge.

The retention factor is measured similarly to paper chromatography, and several methods are used to identify the separated components.

Uses of Thin-layer chromatography (TLC)

To distinguish between the many compounds contained in a combination, thin-layer chromatography is frequently used in labs.
This method aids in the forensic investigation of fibres.
The assay of numerous medicinal goods is also possible using TLC.
It assists in identifying therapeutic plants and their makeup.

References

Wilson, K., Walker, J. (2018). Principles and Techniques of Biochemistry and Molecular Biology (8 eds.). Cambridge University Press: New York.
Ó’Fágáin, C., Cummins, P. M., & O’Connor, B. F. (2017). Gel-Filtration Chromatography. Methods in molecular biology (Clifton, N.J.), 1485, 15–25. https://doi.org/10.1007/978-1-4939-6412-3_2

Sources

3% – https://rd.springer.com/protocol/10.1007/978-1-4939-6412-3_2
1% – https://www.toppr.com/ask/question/chromatography-is-a-method-of-separation-which-works-on-the-principle-of/
1% – https://www.researchgate.net/publication/47556773_Hydrophobic_Interaction_Chromatography
1% – https://brainly.in/question/17535676
1% – https://answersdrive.com/what-is-the-stationary-phase-in-chromatography-73174
<1% – https://www.workplacetesting.com/definition/1293/mobile-phase
<1% – https://www.ukessays.com/essays/biology/the-separation-of-compounds-of-different-polarity-biology-essay.php
<1% – https://www.thoughtco.com/gas-chromatography-4138098
<1% – https://www.studyread.com/types-of-chromatography/
<1% – https://www.studyread.com/chromatography-definition-principle-techniques/
<1% – https://www.slideshare.net/shishirkawde/ion-exchange-chromatography
<1% – https://www.slideshare.net/jabirrahaman/mobile-phase-in-chromatography
<1% – https://www.slideshare.net/GamalAbdulHamid/high-performance-liquid-chromatograph-hplc
<1% – https://www.slideshare.net/ajithnandanam/hydrophobic-interaction-chromatography-hic-theory-and-principle
<1% – https://www.shimadzu.com/an/gc/support/fundamentals/gc.html
<1% – https://www.sciencedirect.com/topics/neuroscience/chromatography
<1% – https://www.sciencedirect.com/topics/materials-science/gel-permeation-chromatography
<1% – https://www.sciencedirect.com/topics/earth-and-planetary-sciences/thin-layer-chromatography
<1% – https://www.sciencedirect.com/topics/chemistry/reverse-phase-liquid-chromatography
<1% – https://www.sciencedirect.com/topics/chemistry/mobile-phase-composition
<1% – https://www.sciencedirect.com/topics/chemistry/liquid-liquid-chromatography
<1% – https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/ion-exchange-chromatography
<1% – https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/mobile-phase-composition
<1% – https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/anion-exchange-resins
<1% – https://www.researchgate.net/publication/309743873_Separation_techniques_Chromatography
<1% – https://www.researchgate.net/publication/259701045_Modeling_of_salt_and_pH_gradient_elution_in_ion-exchange_chromatography
<1% – https://www.researchgate.net/publication/223628077_Separation_and_removal_of_metal_ions_from_dilute_solutions_using_micellar-enhanced_ultrafiltration
<1% – https://www.quora.com/What-is-the-basic-principle-of-high-performance-liquid-chromatography-HPLC
<1% – https://www.quora.com/What-is-Adsorption-Chromatography
<1% – https://www.phmethods.net/sites/default/files/10.5530phm.2017.8.1.pdf
<1% – https://www.pharmatutor.org/articles/flash-chromatography-area-applications
<1% – https://www.ncbi.nlm.nih.gov/pubmed/6175345
<1% – https://www.ncbi.nlm.nih.gov/pubmed/18179225
<1% – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3174051/
<1% – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1529816/
<1% – https://www.mdpi.com/2223-7747/6/4/42/htm
<1% – https://www.lenntech.com/Data-sheets/Ion-Exchange-for-Dummies-RH.pdf
<1% – https://www.lenntech.com/Data-sheets/Dowex-Ion-Exchange-Resins-Fundamentals-L.pdf
<1% – https://www.jove.com/science-education/10187/gas-chromatography-gc-with-flame-ionization-detection
<1% – https://www.jove.com/science-education/10156/high-performance-liquid-chromatography-hplc
<1% – https://www.cytivalifesciences.com/en/us/solutions/protein-research/knowledge-center/protein-purification-methods/ion-exchange-chromatography
<1% – https://www.coursehero.com/file/p745k85/Smaller-molecules-enter-the-pores-of-the-resin-and-diffuse-further-into-the/
<1% – https://www.coursehero.com/file/p2nmhim/Figure-1-shows-a-beaker-containing-mobile-phase-and-a-prepared-paper-stationary/
<1% – https://www.column-chromatography.com/blogs/application-of-column-chromatography-in-pharmacy
<1% – https://www.chemguide.co.uk/analysis/chromatography/paper.html
<1% – https://www.chemguide.co.uk/analysis/chromatography/hplc.html
<1% – https://www.britannica.com/science/stationary-phase-chromatography
<1% – https://www.britannica.com/science/paper-chromatography
<1% – https://www.britannica.com/science/cation-exchange-resin
<1% – https://www.bio-rad.com/en-us/applications-technologies/cation-exchange-chromatography?ID=MWHB018UU
<1% – https://www.bio-rad.com/en-us/applications-technologies/anion-exchange-chromatography?ID=MWHAZ4C4S
<1% – https://www.bio-rad.com/en-uk/applications-technologies/anion-exchange-chromatography?ID=MWHAZ4C4S
<1% – https://www.bio-rad.com/de-de/applications-technologies/cation-exchange-chromatography?ID=MWHB018UU
<1% – https://www.biologydiscussion.com/biochemistry/chromatography-techniques/top-12-types-of-chromatographic-techniques-biochemistry/12730
<1% – https://www.bbc.co.uk/bitesize/guides/zgt6b82/revision/3
<1% – https://www.bbc.co.uk/bitesize/guides/zgbqtfr/revision/7
<1% – https://www.answers.com/Q/What_is_the_role_of_stationary_phase_in_chromatography
<1% – https://vlab.amrita.edu/?sub=2&brch=191&sim=341&cnt=1
<1% – https://satyapsingh.files.wordpress.com/2012/09/chromatography-and-distillation.pdf
<1% – https://sargenttexas.org/chromatography-2/
<1% – https://pediaa.com/what-is-the-difference-between-mobile-phase-and-stationary-phase/
<1% – https://pediaa.com/difference-between-normal-phase-and-reverse-phase-chromatography/
<1% – https://oneofchemistry.blogspot.com/2011/10/thin-layer-chromatography-and-column.html
<1% – https://medical-dictionary.thefreedictionary.com/Flash+column+chromatography
<1% – https://link.springer.com/chapter/10.1007%2F978-3-319-45776-5_12
<1% – https://instrumentationtools.com/chromatography-questions-answers/
<1% – https://en.wikipedia.org/wiki/Stationary_phase_(chemistry)
<1% – https://en.wikipedia.org/wiki/Retardation_factor
<1% – https://en.wikipedia.org/wiki/Monolithic_HPLC_column
<1% – https://en.wikipedia.org/wiki/Metabolomics
<1% – https://en.wikipedia.org/wiki/Chromatography,_thin_layer
<1% – https://en.wikipedia.org/wiki/Chromatography
<1% – https://en.wikibooks.org/wiki/Proteomics/Protein_Separations_-_Chromatography/Hydrophobic_Interaction_Chromatography_(HIC)
<1% – https://core.ac.uk/download/pdf/147603501.pdf
<1% – https://chrominfo.blogspot.com/2020/06/
<1% – https://chem-net.blogspot.com/2013/07/what-is-gas-chromatography-gc.html
<1% – https://chemistry.missouri.edu/sites/default/files/class-files/new_chromatography_lab_2.pdf
<1% – https://chem.libretexts.org/Bookshelves/Ancillary_Materials/Demos%2C_Techniques%2C_and_Experiments/General_Lab_Techniques/Thin_Layer_Chromatography
<1% – https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Supplemental_Modules_(Analytical_Chemistry)/Instrumental_Analysis/Chromatography/High_Performance_Liquid_Chromatography
<1% – https://byjus.com/chemistry/thin-layer-chromatography/
<1% – https://answersdrive.com/what-role-does-polarity-play-in-chromatography-7022293
<1% – http://www.open.edu/openlearn/science-maths-technology/science/biology/nucleic-acids-and-chromatin/content-section-2.4
<1% – http://vlab.amrita.edu/?sub=2&brch=191&sim=341&cnt=1
<1% – http://orgchemboulder.com/Technique/Procedures/Columnchrom/Columnchrom.shtml
<1% – http://europepmc.org/abstract/MED/28058406
<1% – http://biotechisfuture.weebly.com/uploads/1/4/1/6/14160671/affinity_chromatography_1.pdf

Spread the love