Chromatography is an analytical technique, used for separation, identification and purification of the mixture of components. Chromatography Consumables and Chromatography Instrumentation are used in various industries, including pharmaceutical, biotechnology, chemical, environmental, food, and petrochemical industries, for multiple applications. Specifically in pharmaceutical industry, the demand for chromatography instrumentation and chromatography consumables (such as chromatography resin, packed columns) have increased in the recent years for the qualitative and quantitative analysis of a wide range of complex samples.
Components of Chromatography
The various components of chromatography are described below:
Stationary Phase : This phase is composed of solid material (including resins, monolith, membrane, polymers, cellulose and other materials) or liquid adsorbed on the surface of a solid support (supercritical fluids).
Mobile Phase : This phase is composed of liquid or a gaseous component which pass through the stationary phase to separate the analyte.
Analytes : This includes a mixture of components that need to be separated by adding them to mobile phase and passing them through the stationary phase where speed of passing the analyte will separate the analyte.
Principle of Chromatography
The principle of chromatography involves the distribution of mixture of analytes between a moving fluid stream, namely the mobile phase (which can be either a liquid or a gas), and a stationary phase (which can be either a solid or a liquid). During the movement of the sample, components get separated by repeated desorption and sorption in the direction of the mobile phase migration. Several key factors are responsible for the separation process, including differences in molecular weights of analytes, characteristics related to liquid-solid adsorption and partition between liquid-liquid and affinity between molecular weight of analytes. Due to these differences, components of the mixture move at varying speed and some of them stay longer in the stationary phase, while others pass rapidly into mobile phase, and leave the system faster.
Types of Chromatography Techniques
There are different types of chromatography techniques based on the type of stationary and mobile phase.
Classification Based on Bed Type
Chromatography can be classified into two types based on chromatographic bed shape:
Column Chromatography: It is a separation technique wherein the components in a mixture can be separated on the basis of their difference in adsorption on a stationary phase, which then results in their different movement speeds when passed through a stationary column. Most common type of stationary phases used for column chromatography are silica and alumina along with organic solvents which are considered as mobile phase. This type of chromatography is one the most preferred methods for protein purification.
Planar Chromatography: It is a liquid chromatography-based separation technique in which the stationary phase is placed in the form of a planar or flatbed through which mobile phase dissolved with analyte move up by capillary action for the separation of analyte based on adsorption. Planer chromatography can be further classified into two types:
Paper Chromatography: It is a separation technique where the separation of compounds is performed on a specialized paper. This type of chromatography is used for separation of complex mixtures, such as amino acids.
Thin-layer Chromatography: It is a separation technique which is used to separate the mixture of components using a thin stationary phase consisting of adsorbent material layer made up of aluminum oxide and silica supported by a non-reactive layer at the back usually of glass, aluminum and plastics.
Classification based on Physical State
Chromatography techniques can be classified into two types based on physical state of mobile phase; these have been described below:
Gas Chromatography: This separation technique involves the separation of analytes on the basis of retention time of analyte which was dissolved in a gaseous mobile phase depending on the affinity of the molecules to the stationary phase. Different structural compounds act differently with the stationary phase, thereby having different movement speeds in the stationary phase. The sample used in this type of chromatography is either a liquid or a gas.
Liquid Chromatography: It is a separation technique in which the mobile phase is liquid, and the separation of molecules takes place in a column or a plain surface. When liquid mobile phase passes through the column, analytes tend to act differently based on its physiochemical properties and show different speed and get detected by detector.
Classification based on Separation Mechanism
Chromatography techniques can be classified into three types based on their separation mechanism; these have been described below:
Affinity Chromatography: It is a separation technique where the components of a mixture are separated based on their affinity towards the stationary phase of the system.
Ion Exchange Chromatography: It is a technique used for the separation of molecules based on their net surface charge. Ion exchange chromatography can be further categorized into following two types:
Anion Exchange Chromatography: It is a separation technique wherein the negatively charge containing molecules are separated by their interaction with a positive charged anion-exchange resin.
Cation Exchange Chromatography: It is a separation technique wherein the positively charged containing molecules are separated by their interaction with negatively charged ion-exchange resin.
Gel Filtration Chromatography: This technique is also known as gel-exclusion / gel-permeation / molecular-sieve / size-exclusion chromatography. It is a form of partition chromatography that is used to separate molecules on the basis of their molecular sizes.
Future Perspectives of Chromatography Instrumentation and Consumables Market
Chromatography is a versatile technique that has become a valuable separation tool for biomedical and pharmaceutical analysis. In recent years, there has been a growing focus on the advancement of chromatography consumables and chromatography instrumentation to make the purification and separation of several substances easy and efficient. Chromatography instrumentation, such as HPLC, UPLC, LC-MS and GC-MS have high sensitivity, precision, rapid turnover rate and advanced detection capabilities allow the researchers and industries to tackle and solve the complex problems across various processes, thereby leading to increased adoption of such techniques. Increased use of chromatography across various research and industry processes has led to the increased demand for different types of chromatography consumables, such as resins, packed columns, plates and others. As a result, chromatography resins have been considered as an efficient solution to address purification needs of novel COVID-19 vaccines as well as the complex biologic analytes. With the increase in complexity of biologics, their purification needs are anticipated to increase, and chromatography companies are expected to play an important role in developing advanced chromatography instrumentation and convenient consumable formats suitable to the pharmaceutical industry.