Open In App

Purification of Organic Compounds

Last Updated : 08 Jan, 2023
Improve
Improve
Like Article
Like
Save
Share
Report

Organic chemistry is the study of carbon-containing molecules’ structure, characteristics, content, reactions, and production. The majority of organic compounds contain carbon and hydrogen, but they may also contain a variety of other elements (e.g., nitrogen, oxygen, halogens, phosphorus, silicon, and sulfur).

Organic chemistry was originally limited to the study of molecules created by living organisms, but it has now expanded to encompass man-made substances.

Methods of Purification of Organic compounds

Various methods used for the purification of complex organic compounds are discussed below in this article.

  • Sublimation
  • Crystallization
  • Distillation
  • Fractional Distillation
  • Vacuum Distillation
  • Steam Distillation
  • Differential Extraction
  • Chromatography

Sublimation

Conversion of a substance from the solid state to the gaseous state without its becoming liquid. An example is a vaporization of frozen carbon dioxide (dry ice) at ordinary atmospheric pressure and temperature.

Sublimation

 

Crystallization

Crystallization is a method used for the purification of substances. The separation technique separates solids from a liquid.

The process of turning a liquid substance into a highly structured solid whose atoms or molecules are arranged in a well-defined three-dimensional crystal lattice is known as crystallization. A unit cell is a crystal’s tiniest discrete component. There are millions of these unit cells throughout the crystal.

Crystallization

 

Distillation

Distillation is the process of selectively boiling a component in a liquid mixture and then condensing it thereafter. It is a method of separation that can be applied to either get more of one particular component out of a mixture or to separate it out almost completely.

Fractional Distillation

Fractional distillation is a type of distillation that involves the separation of miscible liquids. The process involves repeated distillations and condensations and the mixture is usually separated into component parts. The separation happens when the mixture is heated at a certain temperature where fractions of the mixture start to vaporize.

Fractional Distillation

 

Vacuum Distillation

The boiling point depends on atmospheric pressure; if liquids are distilled in an atmosphere with lower pressure, they will boil at a temperature lower than their boiling points. The vacuum pump is used to do this. Reduced air pressure causes liquids to boil more quickly, which speeds up the entire distillation process.

Vacuum Distillation

 

Steam Distillation

Steam Distillation is a separation process for temperature-sensitive substances. It is an exclusive kind of distillation. Another option is to separate miscible liquid bases based on how volatile they are. an example would be aromatic compounds. It is essential in some industrialized areas. No chemical reaction occurs in this situation

Steam Distillation

 

Differential Extraction

Differential extraction is the method of extracting an organic component from its aqueous solution by shaking it with an organic solvent in which it is insoluble.
As an example, consider the separation of an oil-water mixture.

Chromatography

Chromatography is a technique used to separate mixtures. The mixture is passed through another substance, in this case, filter paper. The different colour ink particles travel at different speeds through the filter paper allowing us to see the constituent colours of the pen ink.

Types of Chromatography

Chromatography is of two types:

  • Adsorption Chromatography
  • Partition Chromatography

Adsorption Chromatography

Adsorption chromatography is a type of chromatography in which the components of a mixture are separated through adsorption.

Adsorption chromatography is one of the oldest chromatography techniques still in use. It employs a mobile phase, which can be either liquid or gaseous, during the process. During the adsorptive process, the mobile phase is adsorbed onto the surface of a stationary solid phase.

Adsorption Chromatography is further classified into:

  • Thin Layer Chromatography
  • Column Chromatography

Thin Layer Chromatography

Thin-layer chromatography (TLC) separates a mixture of chemicals into their constituents using a glass plate coated with a very thin layer of adsorbent, such as silica gel and alumina, as shown in the image below.

In this technique, the glass plate is used. The solution of the to-be-separated mixture is applied as a small spot 2 cm above one end of the plate and the plate is placed in a closed jar containing an eluant, which rises up the plate carrying various components of the mixture to various heights.

Thin Layer Chromatograph

 

Column Chromatography

Column chromatography, as depicted in the image below, is a technique for separating the components of a mixture using a column of appropriate adsorbent packed in a glass tube. The combination is placed on top of the column, and an adequate eluant is allowed to slowly trickle down the column.

The separation of the components occurs depending on the degree of adsorption of the components on the wall adsorbent column. The component with the highest absorptivity is kept at the top, while the others flow down to various heights

Column Chromatography

 

Partition Chromatography

Partition chromatography refers to the chromatography technique that is based on the partitioning of components of a mixture between stationary and mobile phases. It is classified into several types, including paper chromatography, gas-liquid chromatography, liquid-liquid chromatography, and so on.

FAQs on Purification of Organic Compound

Question 1: What is the basic principle of chromatography?

Answer:

Chromatography is based on the idea of separating molecules in a mixture that has been added to the ground or solid and liquid stationary states (stable phase) while travelling with the help of a mobile phase. 

Question 2: What is the Rf value in chromatography?

Answer:

In paper chromatography, RF refers to the distance a fluid component goes up a chromatography plate. All chemicals have a common RF value for each solvent, and RF values are used to match unknown samples with known compounds.

Question 3: What are the four major purifying methods?

Answer:

Four major purifying methods are as follows:

  • Filtering
  • Crystalline Formation
  • Sublimation
  • Distillation

Question 4: How can sublimation be used to purify organic compounds?

Answer: 

Sublimation is the process of transforming a solid into a gas without passing through the liquid state. This technique can be used to purify compounds that are sublimable or have vapor pressures that reach atmospheric pressure well before they reach their melting temperatures.



Previous Article
Next Article

Similar Reads

Organic Farming: Meaning, Benefits, Challenges and Future Prospects of Organic Farming
From the experiences of the past years, it is indicated that modern farming methods have overused the natural resources base. Excessive chemical fertilizers and pesticides were used, which created the problems of loss of soil fertility, and soil and water pollution. Ordinary farming depends intensely on compound composts and poisonous pesticides, e
4 min read
Qualitative Analysis of Organic Compounds
Organic chemistry is a branch of science that studies the structure, properties, and interactions of organic compounds having covalent carbon bonds. By examining their structure, their structural formula can be derived. To better understand their behavior, physical and chemical properties, as well as chemical reactivity, are investigated. The study
10 min read
Organic and Inorganic Compounds
Organic and Inorganic Compounds are two types of compounds based on the presence or absence of carbon-hydrogen (C-H) bonds in their molecular structures. The study of organic compounds is known as organic chemistry, while the study of inorganic compounds is called inorganic chemistry. The distinction between organic and inorganic compounds isn't ea
7 min read
Structural Representations of Organic Compounds
Organic compounds are the most widely used compounds in chemistry as well as in everyday life. Any organic compound has only one chemical formula but can be represented on paper using various structural formulas as per our convenience and the complexity of the structure of the compound. In this article, we shall learn about the various structures u
5 min read
Determination of Boiling Point of Organic Compounds
Determining the boiling point of organic compounds is essential for understanding their properties and behavior. It is the temperature at which a substance changes its state from liquid to gas. Several factors contribute to the boiling point of organic compounds, including intermolecular forces, molecular weight, and symmetry. In this article, we l
7 min read
IUPAC Nomenclature of Organic Compounds
Organic Compounds are those which have Carbon-Hydrogen or Carbon-Carbon bonds. Chemistry is studied under three branches Organic, Inorganic, and Physical Chemistry with each dealing with different types of topics. For this article, we will focus on Organic Chemistry which is the study of carbon and its various compounds. Carbon compounds have a spe
13 min read
Classification of Organic Compounds
Organic compounds are defined as chemical compounds which contain carbon atoms linked with other elements through simple covalent bonds. These elements could be connected by single covalent bonds, double covalent bonds, or triple covalent bonds. In other words, we can say that all organic compounds contain carbon as their central atom. We must note
12 min read
Water Purification
Water is carried through canals or lengthy pipelines in a water purification system, which contains various pollutants and suspended particles from rivers and lakes. River water is commonly used to supply cities with drinking and dining water. This water is unsafe for drinking or dining because it contains a high concentration of suspended pollutan
6 min read
Preparation and Purification of Colloids
Solutions are systems that are homogeneous. When sand is mixed with water, it forms a suspension that settles over time. Colloidal dispersions, or simply colloids, are a large group of systems that exist between the two extremes of suspensions and solutions. A colloid is a heterogeneous system in which one substance is dispersed as very fine partic
7 min read
Difference between Mineral Acids and Organic Acids
Acids are organic substances with acidic characteristics. Acid is also a chemical species that may react with a base to create salt and water. Strong acids and weak acids are the two primary kinds of acids. Depending on their chemical makeup, acids can alternatively be classified as mineral acids or organic acids. The primary distinction between mi
5 min read