GPAT 360

Mass Spectrometry Spectrometry = use of no radia tions. Compound under investigation is bombarded with a beam of electrons to produce the ionic fragments or an ionic molecule of the original species. Resulting charged particles are then separated according to their masses . The spectrum produced shows information abound various masses produced and their relative abundance. PRINCIPLE OF MASS SPECTROMETRY This technique is based on the principle of separation of individual atom or molecule according to difference in their masses. When molecule M is bombarded with a beam of electrons, M + e - à M + + 2e - Resulting ionized molecule M + is then accelerated in an electric field at voltage V. In this condition, the energy given to the particle is eV and this is equal to the kinetic energy (1/2mv 2 ). When there are multiple particles, all the particles will possess the same energy eV and also the same kinetic energy. As the value of ‘m’ in kinetics e...

INFRARED SPECTROSCOPY: BASICS This technique is used for the  structural analysis of molecule.   After absorption of IR radiations, molecules vibrate at many rates of vibrations, which shows various characteristic peaks in the spectrum. Various wavelength ranges (IR): REGION WAVELENGTH (μ) WAVE NUMBER (cm -1 ) Photographic region Visible to 1.2 Visible to 8333.33 Very near IR (Overtone) region 1.2 to 2.5 8300 to 4000 Near IR (Vibration) region 2.5 to 25 4000 to 400 Far IR (Rotation) region 25 to 300-400 400 to 33.33-25 Conversion of wavelength into wavenumber and vice versa: Remember, 1μ =  10 -6 m,  and  cm -1  = 1/cm,  Simply, multiply (1/wavelength) or (1/wavenumber) with  10 4 . Principle of IR spectroscopy: 1. Correct wavelength of radiation: Natural frequency of vibration of a molecule should match...

Ultraviolet Spectroscopy In this anaytical technique, ultraviolet radiations are used. Wavelength ranges of radiations: Visible light : 400 - 800 nm Near UV radiations : 200 - 400 nm Far/ Vacuum UV : below 200 nm Generally, we carry out UV analysis in near UV region of radiations. PRINCIPLE : Electronic transitions When a molecule absorbs UV radiations, the electronic excitation occur where electrons go from lower to higher energy state.  Electronic excitation causes the electron to go from electron bonding orbital to antibonding orbital. After some time electron returns to its original state (stable). While returning to its stable form (into bonding orbital) it releases excess energy. That energy is measured by the detector to access the wavelength (λmax) /absorption pattern. TRANSITIONS: σ → σ* (126-135 nm) n → σ* (180-200 nm) π → π* n → π* ALLOWED TRANSITION:  π → π* FORBIDDEN TRANSITIONS:    n → π* ENERGY OF VARIO...

Pharmaceutical Analysis is one of the interesting subjects in Pharmacy. Knowing how the analysis of compounds is carried out and what actually happens at molecular levels is really interesting.  The answers of questions like 'what happens at molecular levels?', 'What exactly happens when a compound is exposed to various radiations/chemicals during analysis?' are given in the principles of every analytical tool.  Mainly, we need to focus on the principles of analytical methods while preparing for GPAT. Important points you need to focus on while preparing for Pharmaceutical Analysis: (Click on the following topics to read article) 1. Principles (In detail), Instrumentation (parts of the instruments and their role) and applications of -- Ultraviolet (UV-Visible) Spectroscopy Infrared (IR) Spectroscopy Mass spectrometry Nuclear Magnetic Resonance (NMR) Fluorimetry and Flame Photometry Potentiometry, Conductometry and Polarography X-ray Diffracti...

Microencapsulation Microencapsulation is the process by which tiny liquid droplets or solid particles are suspended or coated with a continuous film of polymeric material. Product known as: microcapsules Size : micrometer to millimeter (<1mm) Mononuclear microcapsule Parts of microcapsules: 1. Intrinsic part (inner): Core: contains active ingredient. 2. Extrinsic part (outer): Shell: comprises polymeric material. The shell protects the core from external atmospheres. Core material exists in the form of either a solid, liquid and gas. Core materials --> solutions, suspensions, emulsions. Core material and shell materials should be compatible with each other. Morphology of microcapsules: Mononuclear microcapsules: contain the shell around core. polynuclear microcapsules: contain many cores within a shell. Matrix microcapsules: core material is evenly distributed inside shell material. i.e. API (drug, core) is dispersed in shell (polymer). p...