When you ask for fruit juice in a shop, you don’t get the pure extract of the fruit. The juice actually contains various elements and compounds such as sugar, water and fruit juice. Therefore, it is a mixture and not a pure substance.
The purity of a substance is often determined by measuring its physical properties. Mixtures consist of substances that have their own individual characteristics and properties. Physical properties of the mixed substances indicate the method of separation that can be used. Let’s discuss one of the techniques of separation that is called as chromatography.
Chromatography is based on the concept of partition coefficient. Solute partitions between two immiscible solvents. When we make one solvent immobile (stationery phase) and another mobile it results in most common applications of chromatography. If support is polar. it is forward phase chromatography, and if it is non-polar (C-18) it is reverse phase. The sample analyzed in chromatography, may consist of a single component or mixture of components. When the sample is treated in the course of an analysis, the phases containing the analytes of interest are referred to as the sample whereas everything else is referred to as waste.
Types of chromatography?
In HPLC the sample is forced by a liquid at high pressure (the mobile phase) through a column that is packed with a stationary phase composed of spherically shaped particles. HPLC is divided into two sub-classes based on the polarity of the mobile and stationary phases. Methods wherein stationary phase is more polar than the mobile phase (e.g., toluene as mobile phase, silica as stationary phase) are termed normal phase liquid chromatography (NPLC) and the opposite (e.g., water-methanol mixture as mobile phase and C18=octadecylsilyl as the stationary phase) is termed reversed phase liquid chromatography (RPLC).
Uses of Chromatography in Real World.
Since traditional methods of meat detection and analysis proved to be inconclusive, chromatography was used in Horsemeat Scandal of 2013.
Chromatography is one of the most commonly used chemical processes to separate liquids, solids and gases. According to the Linde Group, the process works by inserting a mixture into a stream of inert gas. The different substances are separated by size, interaction with other media and absorption into chemical detectors.
Drug testing is a common Chromatography application in forensic science.
Journal of Pharmacy Research
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5(5) , Page Number:
Digital Object Identifier: https://dx.doi.org/10.6084/m9.figshare.1008046.v1
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