Neutron Activation Analysis- A Radioactive Analytical Technique
NAA- Neutron Activation Analysis, a radioactive analytical technique applied for the qualitative and quantitative analysis of a substance.
Column Chromatography: Principle, Types, Working & Applications
Column Chromatography is a chromatographic technique in which the separation of constituents of a substance is carried out in a column packed with an adsorbing material. It is a type of adsorption chromatography in which the constituents separate at differential rates in fractions. It is a technique that uses a solid adsorbent material as its stationary phase which is packed in the column and the mobile phase (gas or liquid) runs through it. The most commonly used stationary phase materials are silica gel or alumina whereas organic solvents are the widely used mobile phase in column chromatography. Principle or Column Chromatography Column chromatography is based on the principles of the rate of adsorption of the analyte on the stationary phase according to its affinity with the adsorbent. It states that when a sample is loaded at the top of the column along with the mobile phase, the components of the […]
Gas Chromatography: Principle, Working & Uses
Gas chromatography (GC) is a widely used instrumental method for analytical purposes. GC is an analytical separation and purification technique used to analyze a volatile compound in the gaseous phase. This technique is based on the principles of column chromatography where gas is used as the mobile phase. The stationary phase in GC can be a liquid or solid and based on this the GC can be categorized as Gas-Liquid Chromatography (GLC) or Gas-Solid Chromatography (GSC). The separation in GLC is based on the principle of partition of the analyte into liquid and gas whereas in GSC the separation is based on the adsorption of the analyte on the solid stationary phase. GC was first developed by APJ Martin and Anthony T James in 1951 and it was gas-liquid chromatography based on the principle of partition chromatography. The first gas-solid chromatography was developed by Erika Cremer (German Physical chemist) and […]
Gas Chromatography Mass Spectrometry
GC-MS or Gas Chromatography Mass Spectrometry is a hybrid analytical technique that is used to perform the separation, purification, and identification of a substance simultaneously. The Gas Chromatography component is used to perform the separation and purification of the sample whereas Mass Spectrometry helps in the identification of the substance. In GC-MS two different individual techniques are coupled together to analyze a single substance. Earlier the two techniques were used individually for analysis purposes. In 1950, Fred McLafferty and Roland Gohlke, two Dow Co. researchers, dramatically enhanced the analytical power of GC by coupling it with MS. Adding MS with GC allowed each component exiting the gas chromatograph to be analyzed separately. When taken together, the mass spectra and the chromatographic peaks allowed unambiguous identification of each component. Principle of Gas Chromatography Mass Spectrometry GC-MS uses the principles of both instruments and consolidates them to give a single analytical result […]
High Performance Thin Layer Chromatography (HPTLC)
High performance Thin layer chromatography(HPTLC) is a sophisticated form of Thin layer chromatography. It provides superior separation efficiency. The concept of HPTLC includes validated methods for qualitative and quantitative analysis and fulfills all requirements to be used in the fully-fledged environment. It is also known as planar or flatbed chromatography. A particular advantage of this technique is that it can be combined with mass spectrometric approaches, thus allowing detailed structural characterization of carbohydrate and ceramide moieties. Furthermore, HPTLC can be easily used in the context of so-called overlay techniques Principle of HPTLC HPTLC possesses a similar principle to that of Thin-layer chromatography(TLC) which is principle of adsorption chromatography. The solvent used in the mobile phase flows due to capillary action and the component moves according to their affinity towards adsorbent and eluent. The component with more affinity towards the stationary phase travels faster and the component with less affinity towards […]
Chromatography: The Most Ancient Separation Technique
Every component in this universe is made up of matter, the basic principle which we all learned in chemistry. We also learned that every compound is a mixture of multiple elements. Starting from water to colored solutions everything is a combination of one or more elements, which is why for ages humans have always been curious to separate these compounds to study what they are made up of. Scientists succeeded finally in separating components in the year 1855, when Friedlieb Ferdinand Runge, demonstrated a technique to separate dyes and components of chemicals using a filter paper immersed in another chemical. This was the starting of the most colorful and useful technique we today know as Chromatography. But the evolution of chromatography did not stop with Mr. Runge. In 1900 in Russia, Michael (Mikhail) Tsvet, an Italian botanist tried to separate plant pigments adapting and modifying Runge’s technique. The result he […]
Difference Between Paper Chromatography & Thin Layer Chromatography
Chromatography is a separation technique wherein the different components of a mixture are separated. The mixture to be separated is run through the stationary phase with the help of a mobile phase which separates the different components of a mixture on the basis of partition or adsorption. The history of this technique dates back to 19th century only but it’s true use has attributed to a Russian Botanist named “Mikhail Tsvet” who used this technique to separate the plant pigments which are known by the name of Xanthophylls, Carotenes, Chlorophyll. The use of this technique was limited till the mid 20th century when the researchers Martin and Synge developed Partition chromatography to separate chemical substances with minimum separating coefficients. Paper Chromatography and Thin-layer Chromatography are the two among many chromatographic techniques that were developed with time and have been used continuously in different departments for separation of components. Definition of […]
Thin Layer Chromatography- Principle, Applications and Procedure
Thin Layer Chromatography(TLC) is a separation technique used to separate the components of non-volatile mixtures. TLC is significantly a better separation process than Paper chromatography. TLC was first reported to be used in 1938 in Izmailov and Schreiber. Principle of Thin Layer Chromatography Thin Layer Chromatography is a separation process based on the principle of adsorption in which the components of sample separate based on their affinity towards the stationary and mobile phase where the stationary phase is a thin layer of adsorbent material such as Aluminium oxide, Cellulose, or Silica gel while the mobile phase is the solvent. The separation occurs in a way that the components of higher affinity in a mixture move faster than those which have less affinity towards the stationary phase. When the solvent reaches the solvent front the components are placed at different Rf values and thus the separation is achieved. This procedure of […]
Paper Chromatography- Types, Forensic Significance, Advantages, and Disadvantages
Paper Chromatography is a separation technique in which a substance mixture is separated based on the partition or adsorption principle where cellulose paper is a stationary phase while the solvent is the mobile phase. Paper chromatography is used particularly for separation of lipid samples and chemical substances. Types of Paper Chromatography Paper Chromatography has been classified into 5 types. These are:- Ascending Chromatography Descending Chromatography Ascending-Descending Chromatography Radial Chromatography 2-D Chromatography Ascending Chromatography In this type of Chromatography, the development of chromatogram is done by allowing the mobile phase to run in the upwards direction on the stationary phase. In this method, the solvent is at the bottom of the chamber while the stationary phase is dipped in the chamber with the sample spot just above the solvent. This technique is used for the separation of organic and inorganic substances. Descending Chromatography In this type of Chromatography, the solvent runs […]
Paper Chromatography | Principle and Procedure
Paper chromatography is a planar type of chromatography used for the separation of mixture of substances. It is a simple, inexpensive and a powerful technique that can separate the components by using small quantities of samples. It is a two-dimensional technique which was discovered by Synge and Martin in the year 1943. Principle of Paper Chromatography (PC) Paper chromatography(PC) is based on the principle of both adsorption as well as partition chromatography with a stationary phase (either liquid or solid) and a mobile phase (either gas or liquid). Paper Chromatography is generally based on the principle of partition rather than adsorption wherein the sample solution travels up through the stationary phase separating the components of the mixture based on their migration rate. Paper adsorption Chromatography:- In this principle, the stationary phase is the silica or alumina while solvent is used as the mobile phase. Paper partition Chromatography:- In this principle, […]
Types & Principles of Chromatography
No wonder, being a science student you must be aware of chromatography techniques. We have been studying these techniques since 12th class and are useful in most of the experiments in the lab. Chromatographic techniques are used in Forensic science laboratories for the analysis of samples making it much more necessary for you to learn and understand. Here, I will be explaining to you different Chromatographic techniques and their principles. Introduction to Chromatography It is a separation technique in which a sample is separated based on the principle of adsorption or partition where a sample is separated into different components based on stationary and mobile phases. The stationary phase can be solid or liquid while the mobile phase can be liquid, gas, or supercritical liquid. The term Chromatography (chroma means color and graphien means to write) is the aggregate term for a lot of research facility methods for the partition […]
Electrophoresis: Types & Principle You Should Know About
Electrophoresis is a separation technique where different molecules of a substance are separated depending on their capacity to travel through a stationary phase with respect to the mobile phase. The term electrophoresis is derived from two words i.e., ‘electro’ meaning electricity, and ‘phoresis’ meaning separation. Thus, it can be defined as the separation of serum proteins by the effect of electric current. Arne Tiselius won Nobel prize in Chemistry in 1948 and is considered as the Father of electrophoresis for his research and adsorption analysis for the discovery of the complex nature of serum proteins. Types of Electrophoresis Contingent on the nearness or non-appearance of supporting media the technique can be classified as Moving Boundary and Zone electrophoresis. Moving Boundary Electrophoresis Capillary Electrophoresis Isotachophoresis Immuno Electrophoresis Isoelectrofocusing Zone Electrophoresis Paper Electrophoresis Gel Electrophoresis Thin Layer Electrophoresis Cellulose Acetate Electrophoresis Moving Boundary Electrophoresis This helps in the separation of molecules in […]
