Tag: Chromatography

Introduction

In the lab, chromatography is used to dissect complex mixtures into their constituent parts. The process of separating the components of a mixture is known as chromatography. In order to accomplish this, a mobile phase and a stationary phase are utilised. Since various components in a mixture are subject to varying degrees of influence from the solvent, the mobile phase transports some of the mixture’s components while leaving the stationary phase behind As a result, certain parts will progress quickly while others lag behind. Each component has a unique Rf value. Considering how useful it is in both the purification and analysis processes, it can be found in a wide variety of contexts.

What is the Chromatography technique?

For analytical purposes, a mixture’s distribution into two phases provides a useful starting point for determining how to break it down into its constituent parts. Two such stages are the “mobile” and “stationary” states.

The non-moving phase is called the stationary phase, while the moving phase is called the mobile phase. A glass plate, column, sheet, or anything else is acceptable as the stationary phase. The mobile phase might be either a gas or a liquid.

Since it turns out that every type of molecule has its own unique characteristics. As a result, the Rf value will be unique to each. The Rf number describes how many solute molecules were transported for every one solvent molecule.

Chromatography

What is the Principle of Chromatography?

Chromatography operates on the idea of separating components based on their varied affinities to phases involved. Different components in a combination bind to the mobile phase and the stationary phase with varying strengths.

Applications of Chromatography in the Pharmaceutical Industry

 In the pharmaceutical sector, chromatography is commonly employed as a quality control measure once a chemical has been manufactured.Many different types of chromatography have been used in the pharmaceutical sector. It is employed in both compound analysis and the industrial production of compounds. Separation of chiral substances has also been discovered to benefit from chromatography. 

Applications of Chromatography in the Food Industry

Chromatography has been used for quality control in the food business. Chromatography is useful for determining what kinds of ingredients are in a given dish. Considering the importance of health, it is crucial to pack food with nutrients and vitamins. Several illnesses may be brought on by a deficiency in necessary vitamins and nutrients.

Applications of Chromatography in the Chemical Industry

In the chemical industry, it has applications in the chemical synthesis process. It acts as an assistant for obtaining a particular product. Chromatography has also been used in the pesticide industry for finding the presence of contaminants. For checking the pollutant present in water and air chromatography is used. So it is used in the chemical industry for monitoring several chemical reactions.

Applications of Chromatography in the Field of Molecular Biology

Biological separation using chromatography brings into the world considerable impact on the health and wellness of the people. Without this technique, the preparation method we employ, the synthesis of a particular molecule, etc. will be useless. It has helped researchers to find results faster and with purity. So it has a significant role in molecular biology too.

How is chromatography used in the environmental analysis?

Chromatography has wide application in the analysis of environmental issues. Understanding whether the air is polluted or not is very important since quality air is very essential for the proper living of species. Gas chromatography has been used for this case. 

How is chromatography useful in Forensic Science?

 Chromatography has a vital application in forensic science. For collecting information about the cause of death of a human, chromatography has been employed. It can be used for testing whether a person is infected with some poison, alcohol, drugs, etc. 

Commonly employed chromatography techniques include:

Column chromatography: The stationary phase used in this chromatography is a column and a solvent is used as the mobile phase. Components are separated by their difference in affinity to the solvent. And is used to remove impurities present in a particular compound.

 Ion-exchange chromatography: Separation based on the ions involved in a compound. An ion exchange resin is used as the stationary phase. For water purification, this technique is used.

 Gel-permeation (molecular sieve) chromatography: Separation based on the size of the molecule is gel permeation chromatography. For finding the molecular weight of polymers. This technique is used.

 Affinity chromatography: It is based on specific and highly selective reactions of components present in a mixture. Used for the purification of proteins and nucleic acids.

Paper chromatography: It involves the use of paper as a stationary phase and a solution or solvent as the mobile phase. It is used for purity checking in the pharmaceutical industry.

Thin-layer chromatography: Separation using a thin layer of adsorbent is thin layer chromatography. Mainly used to separate none volatile substances.

Gas chromatography (GS): Separating volatile chemical compounds is gas chromatography. And the mobile phase is a gas stream and a column is used as the stationary phase. It is used widely in the pharmaceutical and cosmeceutical industries.

 Dye-ligand chromatography: Columns pasted with dye ligand act as a stationary phase and are separated with the use of affinity. It is used for protein purification.

Hydrophobic interaction chromatography: This separation of components is based on the hydrophobicity of components. Low water-soluble molecules are separated based on this technique. For example in protein purification. 

 Pseudo Affinity chromatography: The separation of protein molecules by the use of dyes that mimic ligands is pseudo affinity chromatography. It is used in protein purification. 

High-pressure liquid chromatography (HPLC): It involves the use of liquid mobile phase under high pressure and thereby separating molecules from its mixture. It is used in the pharmaceutical industry for the identification of impurities present in it.

Summary

Chromatography is one of the analytical techniques that may be used to separate and purify molecules. It can be used in the pharmaceutical and food industries, among others. Although while analysis is where this technology shines most, it has also been put to use in molecule creation. Chromatography uses two phases—a mobile phase and a stationary phase—to isolate individual substances from a mixture. These phases also serve as a basis for categorising the various chromatographic methods. Methods including gas chromatography, gel permeation chromatography, paper chromatography, high-pressure liquid chromatography, and others are all included.

Frequently Asked Questions

1. What is the difference between flash and preparative chromatography??

Ans: Flash chromatography is used to quickly purify compounds, while preparative chromatography is used to purify compounds with higher resolution.

2. What is isocratic and gradient elution?

Ans: Isocratic elution is used to separate and analyze compounds with a constant mobile phase composition, while gradient elution is used to separate and analyze compounds with a changing mobile phase composition.

3. Which criteria must be followed before selecting a mobile phase?

Ans: Before selecting a mobile phase we need to consider whether it is soluble or insoluble in a particular component that is going to separate. And also need to check the polarity of the compound that has been employed. 

Introduction

A mixture is formed by physical means constituting two or more types of components. A mixture is usually of two types: homogeneous and heterogeneous mixture. Heterogenous mixtures are non-uniform mixtures which do not have a single phase throughout.  The word “homogeneous” has roots in Latin and Greek. The words homo and gene mean “same” and “kind,” respectively. Hence, if a mixture is described as homogenous, all of the mixture’s components are the same. 

What are Homogeneous Mixtures?

Substances in a homogeneous mixture are uniformly distributed across the entire medium. To put it another way, a sample taken from any point within a homogeneous mixture will have the same composition and yield the same results.

If, for instance, a solid-liquid solution is divided in half along its volume, each half will have the same amount of liquid medium and dissolved solute. 

Some essential characteristics of a homogenous mixture are- 

• A pure substance is made primarily of one type of thing, such as sodium metal or hydrogen gas. Homogeneous mixtures and solutions are often referred to as pure materials since their constituent parts are difficult to identify. 
•  The constituents of a homogenous mixture can be split into their original entities through physical means such as evaporation, distillation, etc. 

Classification of homogeneous mixtures:

Homogenous mixtures are usually categorized based on their phase, as follows:

Liquid Homogenous mixture

A solution is a homogenous liquid mixture of two or more substances. When a solute needs to be dissolved, a solvent is used. One such example is water. A solute is primarily a component that is present in lesser quantity. An everyday example is sugar. For illustration, consider the mix of water, sugar, and flavour. 

Solid Homogenous mixture: 

A classic example of a solid homogenous mixture is an alloy. It is solid at room temperature and has the same composition throughout.  

Gaseous Homogenous mixture

A gaseous homogenous mixture has two or more two gases dispersed evenly. For example, the air is a gaseous homogenous mixture with various gases, such as oxygen, carbon dioxide, nitrogen, etc, distributed evenly in the entire space. 

Applications

Homogeneous mixtures have various uses and can be found in many commonplace objects, ranging from man-made polymers to naturally occurring solids like stone.

• Homogeneous mixtures find widespread use in the food business. Products like salad dressings, sauces, and soups are all examples of homogeneous combinations. All of these concoctions result from blending various substances in calculated proportions to get a specific taste or feel.
• The majority of drugs, including cough syrups and eye drops, are homogeneous mixtures. These concoctions are made by combining various active components in a calculated proportion.
• The manufacturing sector also makes use of homogenous mixes. Paints, adhesives, and lubricants are a few examples of products that use homogeneous mixes. To achieve the necessary uniformity or performance, these mixtures are made by combining several elements in a calculated proportion.
• Chemical reactions and chromatography are just two examples of experiments that need uniform solutions. To provide the intended effect, various compounds are combined in a predetermined proportion to produce these mixes.

• Alloys of precious metals like gold, silver, and platinum are produced using homogeneous mixes in the jewellery industry. Many types of jewellery, from rings to necklaces, are crafted from these alloys. The uniform combination of metals results in an appearance and feel that can’t be replicated with just one metal. 
• Homogeneous mixes are utilised to produce lightweight and robust alloys for the aerospace sector. Materials from these alloys are used to fabricate parts for aeroplanes, such as landing gear and fuselage pieces. The alloy produced by the uniform combination of metals is robust and lightweight, making it a good candidate for aeroplane use.

Summary

A homogeneous mixture is a uniform mixture having a clear composition and recognizable characteristics. The components of a homogeneous mixture are invisible. An illustration of a homogeneous mixture is a salt solution dissolved in water. It is impossible to distinguish the salt from the water when it dissolves since it spreads completely throughout the water, producing the same component of the solution.

 

Frequently Asked Questions

1. What are the indications that a mixture is homogeneous?

Ans. Consider the sample size of a combination to determine its nature. It is heterogeneous if there are multiple phases of matter or distinct locations in the sample. The mixture is homogeneous if its composition seems uniform no matter where you examine it.

2. How can a homogenous mixture be separated?

Ans.  Homogenous mixtures cannot be separated by physical means, such as filtration or distillation.

3. Do solutions usually include homogeneous mixtures?

Ans. Although all homogeneous mixtures are solutions, not all solutions are homogeneous mixtures. A homogeneous mixture is a solution if there is only one phase present. When a solute is fully dissolved in a solvent, no undissolved particles remain as a result. 

An Introduction to Chromatography

The Greek words chroma, which means “colour,” and graphein, which means “to write,” are the roots of the word “chromatography.” In this procedure, the mixture to be separated is applied to a stationary phase (solid or liquid), and a pure solvent—such as water or any gas—is then allowed to slowly travel across the stationary phase, transporting the components separately based on their solubility in the pure solvent.

Principle of Chromatography

The chromatography principle is that “a mixture is applied to the surface or into a solid, and the fluid stationary phase (stable phase) separates from each other while moving with the help of the mobile phase”.

How to Separate Components from Black Ink

1. A thin strip of filter paper is cut out and a line is drawn 3 cm above the lower end of the filter paper. This is referred to as the reference line.
2. In the centre of the drawn line, a small dot of black ink is placed.
3. When the dot of black ink is dry, it is lowered into the water-filled chromatography jar.
4. The filter paper should be immersed so that the black ink dot is above the water level in the jar.
5. The setup should be left alone for a while.
6. The component of black ink that is more soluble in the water rises faster and higher up on the filter paper as the water begins to rise from the lower end of the filter paper. The level to which water rises is referred to as the waterfront.
7. Some coloured spots are observed corresponding to the separated components of the black ink, depending on the number of components present in the black ink.

Summary

The sample mixture is dissolved as the solvent rises through the paper, and it then travels up the paper. Because of differences in solubility and attraction to paper, smaller particles travel further than larger particles.

Frequently Asked Questions

1. What are the advantages of Chromatography?

Ans. The advantages of chromatography:

1. A very small quantity of the substance can be separated.
2. Components with very similar physical and chemical properties can be separated.
3. It defines the different constituents of a mixture.
4. It also helps in the quantitative estimation of components of a mixture.

2. What do you mean by Heterogeneous solution?

Ans. A heterogeneous mixture can be defined as a solution with a non-uniform composition, such as dye, milk, and sand water solution.  

3. What are the different types of dyes?

Ans. The natural dyes are henna, walnut shells, turmeric, and catechu. Some synthetic dyes are methyl orange, methyl red, congo red, malachite green, rosaniline, pararosaniline, crystal violet, phenolphthalein, indigo, fluorescein, and anthraquinone dye.