PHARMA KING ACE

THIN LAYER CHROMATOGRAPHY Introduction Thin layer chromatography (TLC) is a technique in which a solute undergoes distribution between two phases, a stationary phase, acting through adsorption and a mobile phase in the form of liquid. The adsorbent is relatively thin, uniform layer of dry, finely powdered material applied to glass, plastic or metal sheet. Glass plates are most commonly used. Separation may also be achieved on the basis of partition or a combination of partition and adsorption, depending on a particular type of support, its preparation and its use with different solvent. Identification can be effected by observation of spots of identical Rf value and about equal magnitude obtained respectively, with an unknown and reference sample chromatograph on the same plate. Apparatus required Flat  glass plates of appropriate dimensions. b)  An aligning tray or plate surface on which the plates can be aligned and        ...

POLARIMETRY Introduction The electric fields associated with the beam of monochromatic light, vibrate in all directions perpendicular to the directions of propagation of light. Certain crystalline materials have different refractive indices for light, whose field vibrates parallel or perpendicular to the principal plane of the crystal. As a result, a Nicol prism constructed of this material transmits only light whose electric field oscillates in one plane. Optical activity concerns with the interaction of such plane polarised light with certain materials, particularly solutions of some organic compounds. When a plane polarised light passes through a medium, it is retarded to an extent indicated by the refractive index of the medium. When the later is optically inactive, both circularly polarised components are retarded to the same extent and the beam emerges from the medium, polarised in the same plane as the incident beam. If the medium is optically active, the components are re...

INTRODUCTION AND BASICS OF UV SPECTROSCOPY UV spectroscopy is type of absorption spectroscopy in which light of ultra-violet region (200-400 nm.) is absorbed by the molecule. Absorption of the ultra-violet radiations results in the excitation of the electrons from the ground state to higher energy state. The energy of the ultra-violet radiation that are absorbed is equal to the energy difference between the ground state and higher energy states (deltaE = hf). Generally, the most favoured transition is from the highest occupied molecular orbital (HOMO) to lowest unoccupied molecular orbital (LUMO). For most of the molecules, the lowest energy occupied molecular orbital’s are s orbital, which correspond to sigma bonds. The p orbitals are at somewhat higher energy levels, the orbital’s (nonbonding orbitals) with unshared paired of electrons lie at higher energy levels. The unoccupied or anti-bonding orbitals (pie* and sigma*) are the highest energy occupied orbitals. In all ...

A titration (titrimetry) is a technique where a solution of known concentration is used to determine the concentration of an unknown solution. Typically, the titrant (the know solution) is added from a buret   to a known quantity of the analyte (the unknown solution) until the reaction is complete. Knowing the volume of titrant added allows the determination of the concentration of the unknown. Often, an indicator is used to usually signal the end of the reaction, the endpoint. Titrations can be classified by the type of reaction. Different types of titration reaction include: Acid-base titrations are based on the neutralization reaction between the analyte and an acidic or basic titrant. These most commonly use a pH indicator, a pH meter, or a conductance meter to determine the endpoint. Redox titrations are based on an oxidation-reduction reaction between the analyte and titrant. These most commonly use a potentiometer or a redox indicator t...