Chromatography Quiz

Introduction to Chromatography: Techniques, Principles, and Objectives

• Chromatography is a process of separating a mixture into its components while moving through a bed of fixed porous solid having different and reversible affinities for substances being separated.
• The technique was first developed in 1901 by Michael Tswett, who named the method "Chromatography" (Chroma= color; Graphy= to write).
• Chromatography is widely used for the separation, identification, and determination of the chemical components in complex mixtures.
• The process involves two phases: a stationary phase (fixed bed of large surface area) and a mobile phase (fluid that moves through or over the surface of the fixed phase).
• The separated drug principle can be removed from its absorbing solid by elution (use of a flowing solvent where the drug has higher affinity) or simple solvent extraction (solvent partitioning).
• Chromatography has various objectives, including resolution of mixture into constituent parts, determination of homogeneity, purification, concentration of substances from dilute solutions, identification and control of technical products, quantitative separation from complex mixtures, and identification of molecular structure.
• The basic principles of chromatography include adsorption, partition, ion-exchange, and molecular exclusion.
• Adsorption chromatography brings about the separation of a mixture through a competitive process in which the molecules of the mobile phase compete with analyte molecules for polar adsorption sites on the adsorbent.
• Partition chromatography is based on a thin film formed on the surface of a solid support by a liquid stationary phase, and solutes equilibrate between the mobile phase and stationary phase.
• Paper chromatography uses either adsorption or partition chromatography, with the stationary phase being paper impregnated with silica or alumina or moisture or water present in the pores of the cellulose fibers found in the paper, respectively.
• The separation can be influenced by the mobile phase and adsorbent, and the elution can be controlled by the elutropic series.
• Chromatography is a versatile technique that has revolutionized the way complex mixtures are analyzed and has applications in various fields, such as pharmaceuticals, forensics, food science, and environmental science.