- The document is a presentation on ultraviolet spectroscopy submitted by Moriyom Akhter and Md Shah Alam from the Department of Pharmacy at World University of Bangladesh.
- It defines ultraviolet spectroscopy and discusses key concepts like absorption spectra, types of electronic transitions that can occur, Beer's and Lambert's absorption laws, instrumentation components, and applications in qualitative and quantitative analysis.
- The presentation also examines effects of chromophores and auxochromes on absorption spectra and maximum wavelengths, and how solvents can shift absorption peaks.
This presentation include the detailed explanation of various parts of a UV-Visible spectrophotometer and two types of UV-Visible spectrophotometers-Single beam and Doube beam. It also include the comparison between single beam and double beam spectrophotometers.
This document provides an overview of the principles of UV-visible spectroscopy. It discusses how UV-visible spectroscopy involves exciting electrons from lower to higher orbital energies using electromagnetic radiation between 200-800nm. The absorption of radiation is dependent on the structure of the compound and type of electron transition. The main types of electron transitions are σ->σ*, n->π*, π->π*, and n->σ*. Selection rules determine which transitions are allowed. UV-visible spectroscopy is used in pharmaceutical analysis for qualitative, quantitative, and structural analysis of compounds in solution.
UV-visible spectroscopy is a technique that uses light in the visible and adjacent ranges. It works by measuring how much light is absorbed by a sample at each wavelength.
The document discusses the basic principles of spectroscopy, including how electromagnetic radiation interacts with matter. It describes the laws of absorption, specifically Beer's law, which states that absorbance is proportional to concentration.
The key aspects of instrumentation are outlined, including light sources, wavelength selectors like monochromators, sample holders, and detection devices. Single beam and double beam spectrophotometers are explained as the main types of instruments used in UV-visible spectroscopy.
Detectors are the brain of any chromatograhic system. It help us to record the chromatogram based on certain characteristics of the analyte and help us in identifying that compound both qualitatively and quantitatively.
This presentation gives you thorough knowledge about the IR Spectroscopy. This include basic principle, type of vibrations, factors influencing vibrational frequency, instrumentation and applications of IR Spectroscopy. This is the most widely used technique for identifying unknown functional group depending on the vibrational frequency.
IR SPECTROSCOPY, INTRODUCTION, PRINCIPLE, THEORY, FATE OF ABSORBED RADIATION, FERMI RESONANCE, FINGERPRINT REGION, VIBRATIONS, FACTORS AFFECTING ABSORPTION OF IR RADIATION, SAMPLING TECHNIQUES, APPLICATIONS OF IR SPECTROSCOPY.
a substance can absorb any visible light or external radiation and then again emit it. this called fluorescence and the process of reduction in fluorescence intensity is called quenching. this presentation is all about quenching of fluorescence.
UV/visible spectroscopy involves the interaction of electromagnetic radiation with matter. Absorption spectroscopy measures the absorption of UV or visible light, while emission spectroscopy measures light emitted from a sample. The wavelength and frequency of electromagnetic radiation are inversely related by the equation c=λν. Electronic transitions in molecules, such as σ→σ*, π→π*, n→σ*, and n→π* can be detected using UV/visible spectroscopy. Beer's law states that absorbance is directly proportional to concentration and path length. Chromophores are functional groups in molecules that absorb UV or visible light.
This presentation include the detailed explanation of various parts of a UV-Visible spectrophotometer and two types of UV-Visible spectrophotometers-Single beam and Doube beam. It also include the comparison between single beam and double beam spectrophotometers.
This document provides an overview of the principles of UV-visible spectroscopy. It discusses how UV-visible spectroscopy involves exciting electrons from lower to higher orbital energies using electromagnetic radiation between 200-800nm. The absorption of radiation is dependent on the structure of the compound and type of electron transition. The main types of electron transitions are σ->σ*, n->π*, π->π*, and n->σ*. Selection rules determine which transitions are allowed. UV-visible spectroscopy is used in pharmaceutical analysis for qualitative, quantitative, and structural analysis of compounds in solution.
UV-visible spectroscopy is a technique that uses light in the visible and adjacent ranges. It works by measuring how much light is absorbed by a sample at each wavelength.
The document discusses the basic principles of spectroscopy, including how electromagnetic radiation interacts with matter. It describes the laws of absorption, specifically Beer's law, which states that absorbance is proportional to concentration.
The key aspects of instrumentation are outlined, including light sources, wavelength selectors like monochromators, sample holders, and detection devices. Single beam and double beam spectrophotometers are explained as the main types of instruments used in UV-visible spectroscopy.
Detectors are the brain of any chromatograhic system. It help us to record the chromatogram based on certain characteristics of the analyte and help us in identifying that compound both qualitatively and quantitatively.
This presentation gives you thorough knowledge about the IR Spectroscopy. This include basic principle, type of vibrations, factors influencing vibrational frequency, instrumentation and applications of IR Spectroscopy. This is the most widely used technique for identifying unknown functional group depending on the vibrational frequency.
IR SPECTROSCOPY, INTRODUCTION, PRINCIPLE, THEORY, FATE OF ABSORBED RADIATION, FERMI RESONANCE, FINGERPRINT REGION, VIBRATIONS, FACTORS AFFECTING ABSORPTION OF IR RADIATION, SAMPLING TECHNIQUES, APPLICATIONS OF IR SPECTROSCOPY.
a substance can absorb any visible light or external radiation and then again emit it. this called fluorescence and the process of reduction in fluorescence intensity is called quenching. this presentation is all about quenching of fluorescence.
UV/visible spectroscopy involves the interaction of electromagnetic radiation with matter. Absorption spectroscopy measures the absorption of UV or visible light, while emission spectroscopy measures light emitted from a sample. The wavelength and frequency of electromagnetic radiation are inversely related by the equation c=λν. Electronic transitions in molecules, such as σ→σ*, π→π*, n→σ*, and n→π* can be detected using UV/visible spectroscopy. Beer's law states that absorbance is directly proportional to concentration and path length. Chromophores are functional groups in molecules that absorb UV or visible light.
The document discusses infrared (IR) absorption spectroscopy. It begins by defining IR spectroscopy and explaining that it deals with the infrared region of the electromagnetic spectrum. It then discusses the different IR regions and how IR radiation causes molecular vibrations when it hits a molecule. The document goes on to describe different types of molecular vibrations including stretching, bending, scissoring, and twisting vibrations. It also discusses factors that affect vibrational frequencies such as atomic mass and bond strength. Finally, it briefly discusses instrumentation used in IR spectroscopy such as sources, sample cells, detectors, and the applications of IR spectroscopy.
This document discusses ion exchange chromatography, including its principle, types of ion exchange resins, practical requirements, factors affecting separation, and applications. Ion exchange chromatography separates ions based on their affinity for ion exchange resins through reversible ion exchange reactions. There are two main types of resins - cation exchange resins that separate cations and anion exchange resins that separate anions. Key factors that affect ion exchange separations are the nature of the ions and properties of the resins, such as cross-linking and swelling. Ion exchange chromatography has various applications, including water softening, producing deionized water, separating and purifying metals and ions, and analysis/purification in fields like biochemistry.
Ion exchange chromatography separates ions and polar molecules based on their affinity for an ion exchange resin. It works through the reversible electrostatic interaction between ions in solution and ions attached to the resin. There are four main types of resins: strong cation, weak cation, strong anion, and weak anion. Organic resins like polystyrene with divinylbenzene crosslinking are commonly used. The process involves equilibrating, applying the sample, eluting components at different rates depending on their affinity, and regenerating the resin. Ion exchange chromatography has applications like water softening, enzyme purification, and separation of ions, sugars, amino acids and proteins.
The document discusses infrared (IR) spectroscopy, which analyzes the interaction of infrared radiation with matter. IR spectroscopy can provide information about a compound's chemical structure and molecular structure by measuring its absorption of IR radiation. It is widely used to analyze organic materials and some inorganic molecules. The document then describes various components of IR instrumentation, including IR radiation sources like the Nernst glower and globar, monochromators that separate wavelengths, sample cells and techniques, and detectors like thermocouples, bolometers, and thermistors that measure the radiation absorbed.
NMR spectroscopy is a technique that uses magnetic fields and radiofrequency pulses to analyze atomic nuclei and study the physical and chemical properties of molecules. It provides detailed information about molecular structure by detecting hydrogen and other nuclei. The document discusses the basic principles of NMR, instrumentation, factors affecting chemical shifts, and applications in medicine such as anatomical imaging and tumor detection.
The document discusses fluorescence spectroscopy. It defines fluorescence as emission of light that occurs when a substance absorbs light and returns to its ground state, emitting photons. Factors that affect fluorescence include the molecular structure, substituents, concentration, pH, temperature, and viscosity. Instrumentation for fluorescence spectroscopy includes a light source, filters, sample cells, and detectors such as photomultiplier tubes. Applications of fluorescence spectroscopy include determination of inorganic substances, use as fluorescent indicators, pharmaceutical analysis, and liquid chromatography.
This document provides an overview of infrared (IR) spectroscopy. It discusses the IR region of the electromagnetic spectrum, the basic principles of IR spectroscopy, and factors that influence molecular vibrations. Requirements for IR absorption include an electric dipole moment and the radiation wavelength matching the natural vibration frequency. Molecular vibrations observed in IR spectroscopy include stretches, bends, and rotations. Instrumentation components like IR sources, wavelength selectors, detectors, and sample handling techniques are also outlined. Finally, applications of IR spectroscopy like structure elucidation and identification of functional groups are mentioned.
UV-visible spectroscopy is a technique that uses light in the visible and adjacent ranges. It works by measuring how much light is absorbed by a sample at each wavelength. There are several types of electronic transitions that can occur when molecules absorb this light. The amount of light absorbed follows Beer's law and is proportional to the concentration and path length of the sample. A UV-visible spectrophotometer consists of a light source, monochromator, sample holder, detector, and recording device. This technique has many applications including detection of impurities, structure elucidation, and quantitative analysis in pharmaceutical analysis.
Ultraviolet-visible (UV-Vis) spectrophotometry is a technique used to measure light absorbance across the ultraviolet and visible ranges of the electromagnetic spectrum. When incident light strikes matter it can either be absorbed, reflected, or transmitted. The absorbance of radiation in the UV-Vis range causes atomic excitation, which refers to the transition of molecules from a low-energy ground state to an excited state.
1) IR spectroscopy uses infrared radiation to identify chemical substances by their absorption patterns.
2) The main components of an IR spectrometer are a radiation source, monochromator, sample cells, detectors, and recorder.
3) Common radiation sources are Nernst glowers, globar sources, and incandescent wires, which emit IR radiation that is focused through the sample.
Affinity chromatography is a method used to separate biochemical mixtures based on highly specific interactions like antigen-antibody binding. It works by coupling a ligand to a stationary phase gel that can trap molecules of interest from a mobile phase solution. Unbound molecules are washed away while bound molecules are later released through elution. Common uses include purifying proteins, nucleic acids, antibodies, and enzymes from mixtures by exploiting properties like metal ion binding or interactions with lectins or ligands.
This document describes the components and design of spectrophotometry instruments. It discusses the key components including the light source, monochromator system using filters, prisms or gratings, sample holder, detector and readout. Specific light sources like tungsten-halogen lamps, hydrogen and xenon discharge lamps are covered. Requirements for an ideal light source and operating principles of filters, prisms and diffraction gratings as monochromators are summarized.
This document provides an overview of Fourier Transform Infrared (FT-IR) Spectroscopy. It explains that FT-IR spectroscopy uses an interferometer to measure all infrared frequencies simultaneously, whereas dispersive infrared spectroscopy measures them sequentially. This allows FT-IR to produce spectra much faster. The document also outlines the key components of an FT-IR system, including the Michelson interferometer, beam splitter, fixed and moving mirrors, and how a Fourier transform is used to convert the interferogram signal into an infrared spectrum. Finally, some advantages of FT-IR are noted, such as improved sensitivity and ability to analyze a wide range of sample types.
This document provides an overview of mass spectrometry. It begins with introductions to spectroscopy and mass spectroscopy. The basic principles of mass spectrometry are that molecules are ionized, the ions are accelerated and passed through electric and magnetic fields based on their mass-to-charge ratio, and detected. Common ionization techniques include electron ionization, chemical ionization, and desorption techniques like fast atom bombardment. The document describes different types of ions detected, such as molecular, fragment, and rearrangement ions. It also covers various mass analyzers used to separate ions such as magnetic sector, double focusing, and quadrupole analyzers.
Gas chromatography is a technique used to separate and analyze mixtures that can be vaporized without decomposition. It works by partitioning components to be separated between a stationary phase and a mobile gas phase. The key components of a gas chromatography instrument are the carrier gas, injection port, column, temperature control system, and detector. Factors like temperature, flow rate, column length, and amount of sample injected can influence separation of the components. Gas chromatography has applications in qualitative and quantitative analysis and is used in quality control of pharmaceuticals.
This document discusses Beer's law and Lambert's law, which describe how the intensity of light passing through an absorbing medium decreases exponentially with increasing thickness and concentration of the medium. It states that Beer's law relates the decrease in intensity to both the thickness and concentration, while Lambert's law relates it only to thickness. The document also describes deviations from the linear relationship predicted by these laws that can occur, including positive deviations where concentration changes have a greater than expected effect, and negative deviations where changes have a smaller effect. Possible causes of deviations, both instrumental and physicochemical, are outlined.
This document provides an overview of UV-Visible Spectroscopy. It discusses the basic principles including electromagnetic radiation, interaction of radiation with matter, and electronic transitions. It describes Beer-Lambert's law and how absorbance is directly proportional to concentration and path length. Different types of electronic transitions like σ→σ*, n→σ*, π→π*, and n→π* are explained. Instrumentation components like radiation sources, monochromators, sample holders and detectors are briefly outlined. Key terms like chromophore, auxochrome, bathochromic shift, hypsochromic shift, hyperchromic effect and hypochromic effect are also defined.
Column chromatography is a separation technique that uses a stationary phase, usually a solid, and a mobile liquid phase to separate mixtures. It was developed in 1900 and involves passing a liquid containing dissolved compounds through a column packed with a solid adsorbent. Components separate based on their different interactions with the stationary and mobile phases, with less strongly adsorbed compounds eluting more quickly. Column chromatography is useful for purifying compounds and isolating constituents from mixtures.
principle, application and instrumentation of UV- visible Spectrophotometer Ayetenew Abita Desa
This Presentation powerpoint includes the principle, application, and instrumentation of UV- Visible Spectrophotometer. It covers beer-lambert low and its quantitative applications. It also includes the qualitative applications in different fields of study. Presented at Addis Ababa University, School of medicine, department of medical biochemistry.
Mass spectroscopy is a technique used to analyze molecules. It involves ionizing molecules using electrons, accelerating the ions, and separating them based on their mass-to-charge ratio using electric or magnetic fields. The ions are then detected, producing a mass spectrum that is unique to each molecule and can be used to determine molecular structure. Mass spectroscopy requires only a small amount of sample and provides accurate molecular mass and elemental composition information. It is a destructive technique as the sample is consumed during ionization and fragmentation processes.
Principle and instrumentation of UV-visible spectrophotometer.Protik Biswas
UV-visible spectrophotometry uses light in the ultraviolet and visible range to analyze substances. When light passes through a sample, some is absorbed and some is transmitted. The ratio of light entering versus exiting the sample is used to calculate absorbance, which follows Beer's Law - absorbance is directly proportional to concentration. A spectrophotometer consists of a light source, monochromator to isolate wavelengths, sample holder, and detector to measure transmitted light intensity and thus absorbance. This allows analysis of concentration for substances that absorb specific wavelengths of UV or visible light.
This document provides an overview of UV-Visible spectroscopy. It discusses how UV radiation causes electronic transitions in molecules, which can be observed via absorption spectroscopy. The instrumentation used includes sources of UV and visible light, a monochromator to select wavelengths, and a detector. Samples are dissolved and placed in transparent cuvettes for analysis. Spectra are recorded as absorbances and show absorption bands corresponding to electronic transitions. UV-Vis is useful for structure elucidation and quantitative analysis.
The document discusses infrared (IR) absorption spectroscopy. It begins by defining IR spectroscopy and explaining that it deals with the infrared region of the electromagnetic spectrum. It then discusses the different IR regions and how IR radiation causes molecular vibrations when it hits a molecule. The document goes on to describe different types of molecular vibrations including stretching, bending, scissoring, and twisting vibrations. It also discusses factors that affect vibrational frequencies such as atomic mass and bond strength. Finally, it briefly discusses instrumentation used in IR spectroscopy such as sources, sample cells, detectors, and the applications of IR spectroscopy.
This document discusses ion exchange chromatography, including its principle, types of ion exchange resins, practical requirements, factors affecting separation, and applications. Ion exchange chromatography separates ions based on their affinity for ion exchange resins through reversible ion exchange reactions. There are two main types of resins - cation exchange resins that separate cations and anion exchange resins that separate anions. Key factors that affect ion exchange separations are the nature of the ions and properties of the resins, such as cross-linking and swelling. Ion exchange chromatography has various applications, including water softening, producing deionized water, separating and purifying metals and ions, and analysis/purification in fields like biochemistry.
Ion exchange chromatography separates ions and polar molecules based on their affinity for an ion exchange resin. It works through the reversible electrostatic interaction between ions in solution and ions attached to the resin. There are four main types of resins: strong cation, weak cation, strong anion, and weak anion. Organic resins like polystyrene with divinylbenzene crosslinking are commonly used. The process involves equilibrating, applying the sample, eluting components at different rates depending on their affinity, and regenerating the resin. Ion exchange chromatography has applications like water softening, enzyme purification, and separation of ions, sugars, amino acids and proteins.
The document discusses infrared (IR) spectroscopy, which analyzes the interaction of infrared radiation with matter. IR spectroscopy can provide information about a compound's chemical structure and molecular structure by measuring its absorption of IR radiation. It is widely used to analyze organic materials and some inorganic molecules. The document then describes various components of IR instrumentation, including IR radiation sources like the Nernst glower and globar, monochromators that separate wavelengths, sample cells and techniques, and detectors like thermocouples, bolometers, and thermistors that measure the radiation absorbed.
NMR spectroscopy is a technique that uses magnetic fields and radiofrequency pulses to analyze atomic nuclei and study the physical and chemical properties of molecules. It provides detailed information about molecular structure by detecting hydrogen and other nuclei. The document discusses the basic principles of NMR, instrumentation, factors affecting chemical shifts, and applications in medicine such as anatomical imaging and tumor detection.
The document discusses fluorescence spectroscopy. It defines fluorescence as emission of light that occurs when a substance absorbs light and returns to its ground state, emitting photons. Factors that affect fluorescence include the molecular structure, substituents, concentration, pH, temperature, and viscosity. Instrumentation for fluorescence spectroscopy includes a light source, filters, sample cells, and detectors such as photomultiplier tubes. Applications of fluorescence spectroscopy include determination of inorganic substances, use as fluorescent indicators, pharmaceutical analysis, and liquid chromatography.
This document provides an overview of infrared (IR) spectroscopy. It discusses the IR region of the electromagnetic spectrum, the basic principles of IR spectroscopy, and factors that influence molecular vibrations. Requirements for IR absorption include an electric dipole moment and the radiation wavelength matching the natural vibration frequency. Molecular vibrations observed in IR spectroscopy include stretches, bends, and rotations. Instrumentation components like IR sources, wavelength selectors, detectors, and sample handling techniques are also outlined. Finally, applications of IR spectroscopy like structure elucidation and identification of functional groups are mentioned.
UV-visible spectroscopy is a technique that uses light in the visible and adjacent ranges. It works by measuring how much light is absorbed by a sample at each wavelength. There are several types of electronic transitions that can occur when molecules absorb this light. The amount of light absorbed follows Beer's law and is proportional to the concentration and path length of the sample. A UV-visible spectrophotometer consists of a light source, monochromator, sample holder, detector, and recording device. This technique has many applications including detection of impurities, structure elucidation, and quantitative analysis in pharmaceutical analysis.
Ultraviolet-visible (UV-Vis) spectrophotometry is a technique used to measure light absorbance across the ultraviolet and visible ranges of the electromagnetic spectrum. When incident light strikes matter it can either be absorbed, reflected, or transmitted. The absorbance of radiation in the UV-Vis range causes atomic excitation, which refers to the transition of molecules from a low-energy ground state to an excited state.
1) IR spectroscopy uses infrared radiation to identify chemical substances by their absorption patterns.
2) The main components of an IR spectrometer are a radiation source, monochromator, sample cells, detectors, and recorder.
3) Common radiation sources are Nernst glowers, globar sources, and incandescent wires, which emit IR radiation that is focused through the sample.
Affinity chromatography is a method used to separate biochemical mixtures based on highly specific interactions like antigen-antibody binding. It works by coupling a ligand to a stationary phase gel that can trap molecules of interest from a mobile phase solution. Unbound molecules are washed away while bound molecules are later released through elution. Common uses include purifying proteins, nucleic acids, antibodies, and enzymes from mixtures by exploiting properties like metal ion binding or interactions with lectins or ligands.
This document describes the components and design of spectrophotometry instruments. It discusses the key components including the light source, monochromator system using filters, prisms or gratings, sample holder, detector and readout. Specific light sources like tungsten-halogen lamps, hydrogen and xenon discharge lamps are covered. Requirements for an ideal light source and operating principles of filters, prisms and diffraction gratings as monochromators are summarized.
This document provides an overview of Fourier Transform Infrared (FT-IR) Spectroscopy. It explains that FT-IR spectroscopy uses an interferometer to measure all infrared frequencies simultaneously, whereas dispersive infrared spectroscopy measures them sequentially. This allows FT-IR to produce spectra much faster. The document also outlines the key components of an FT-IR system, including the Michelson interferometer, beam splitter, fixed and moving mirrors, and how a Fourier transform is used to convert the interferogram signal into an infrared spectrum. Finally, some advantages of FT-IR are noted, such as improved sensitivity and ability to analyze a wide range of sample types.
This document provides an overview of mass spectrometry. It begins with introductions to spectroscopy and mass spectroscopy. The basic principles of mass spectrometry are that molecules are ionized, the ions are accelerated and passed through electric and magnetic fields based on their mass-to-charge ratio, and detected. Common ionization techniques include electron ionization, chemical ionization, and desorption techniques like fast atom bombardment. The document describes different types of ions detected, such as molecular, fragment, and rearrangement ions. It also covers various mass analyzers used to separate ions such as magnetic sector, double focusing, and quadrupole analyzers.
Gas chromatography is a technique used to separate and analyze mixtures that can be vaporized without decomposition. It works by partitioning components to be separated between a stationary phase and a mobile gas phase. The key components of a gas chromatography instrument are the carrier gas, injection port, column, temperature control system, and detector. Factors like temperature, flow rate, column length, and amount of sample injected can influence separation of the components. Gas chromatography has applications in qualitative and quantitative analysis and is used in quality control of pharmaceuticals.
This document discusses Beer's law and Lambert's law, which describe how the intensity of light passing through an absorbing medium decreases exponentially with increasing thickness and concentration of the medium. It states that Beer's law relates the decrease in intensity to both the thickness and concentration, while Lambert's law relates it only to thickness. The document also describes deviations from the linear relationship predicted by these laws that can occur, including positive deviations where concentration changes have a greater than expected effect, and negative deviations where changes have a smaller effect. Possible causes of deviations, both instrumental and physicochemical, are outlined.
This document provides an overview of UV-Visible Spectroscopy. It discusses the basic principles including electromagnetic radiation, interaction of radiation with matter, and electronic transitions. It describes Beer-Lambert's law and how absorbance is directly proportional to concentration and path length. Different types of electronic transitions like σ→σ*, n→σ*, π→π*, and n→π* are explained. Instrumentation components like radiation sources, monochromators, sample holders and detectors are briefly outlined. Key terms like chromophore, auxochrome, bathochromic shift, hypsochromic shift, hyperchromic effect and hypochromic effect are also defined.
Column chromatography is a separation technique that uses a stationary phase, usually a solid, and a mobile liquid phase to separate mixtures. It was developed in 1900 and involves passing a liquid containing dissolved compounds through a column packed with a solid adsorbent. Components separate based on their different interactions with the stationary and mobile phases, with less strongly adsorbed compounds eluting more quickly. Column chromatography is useful for purifying compounds and isolating constituents from mixtures.
principle, application and instrumentation of UV- visible Spectrophotometer Ayetenew Abita Desa
This Presentation powerpoint includes the principle, application, and instrumentation of UV- Visible Spectrophotometer. It covers beer-lambert low and its quantitative applications. It also includes the qualitative applications in different fields of study. Presented at Addis Ababa University, School of medicine, department of medical biochemistry.
Mass spectroscopy is a technique used to analyze molecules. It involves ionizing molecules using electrons, accelerating the ions, and separating them based on their mass-to-charge ratio using electric or magnetic fields. The ions are then detected, producing a mass spectrum that is unique to each molecule and can be used to determine molecular structure. Mass spectroscopy requires only a small amount of sample and provides accurate molecular mass and elemental composition information. It is a destructive technique as the sample is consumed during ionization and fragmentation processes.
Principle and instrumentation of UV-visible spectrophotometer.Protik Biswas
UV-visible spectrophotometry uses light in the ultraviolet and visible range to analyze substances. When light passes through a sample, some is absorbed and some is transmitted. The ratio of light entering versus exiting the sample is used to calculate absorbance, which follows Beer's Law - absorbance is directly proportional to concentration. A spectrophotometer consists of a light source, monochromator to isolate wavelengths, sample holder, and detector to measure transmitted light intensity and thus absorbance. This allows analysis of concentration for substances that absorb specific wavelengths of UV or visible light.
This document provides an overview of UV-Visible spectroscopy. It discusses how UV radiation causes electronic transitions in molecules, which can be observed via absorption spectroscopy. The instrumentation used includes sources of UV and visible light, a monochromator to select wavelengths, and a detector. Samples are dissolved and placed in transparent cuvettes for analysis. Spectra are recorded as absorbances and show absorption bands corresponding to electronic transitions. UV-Vis is useful for structure elucidation and quantitative analysis.
Introduction and Principle of IR spectroscopyRajaram Kshetri
This document provides an introduction to infrared (IR) spectrophotometry. It discusses how IR spectroscopy analyzes molecular vibrations when molecules absorb IR radiation that matches their natural vibrational frequencies. The document outlines the principle of IR spectroscopy and describes the different types of molecular vibrations observed in IR spectra, including stretching and bending vibrations. It also discusses the criteria for a molecule to absorb IR radiation, such as having a change in dipole moment when vibrations occur.
UV/visible spectroscopy involves measuring the absorption of ultraviolet or visible light by molecules. It utilizes light in the wavelength range of 200-800 nm.
The key components of a UV-visible spectrophotometer are a light source, wavelength selector such as a monochromator, sample holder, detector, and associated electronics. Common light sources include deuterium lamps, tungsten lamps, and mercury lamps. Samples are typically held in quartz or glass cuvettes. Detectors include phototubes and photodiodes.
UV-visible spectroscopy can be used to analyze samples containing multiple components. Methods for multicomponent analysis include simultaneous equations using absorption data at two wavelengths, absorbance ratio methods
This document provides an overview of UV-visible spectroscopy. It begins with an introduction to UV-visible spectroscopy and electromagnetic radiation. It then discusses the principle, instrumentation, applications, and derivative spectroscopy of UV-visible spectroscopy. The document also covers topics such as absorption laws, chromophores, solvent effects, and the Woodward-Feiser rule for calculating absorption maxima based on molecular structure.
This document provides an overview of UV-visible spectroscopy. It discusses the electromagnetic spectrum and how light exhibits both wave and particle properties. It explains the basic components and principles of UV-visible spectrometers, including sources such as tungsten lamps and lasers, wavelength selectors like monochromators, sample containers, and various types of detectors. It also covers important concepts such as Beer's law, deviations from Beer's law, and the factors that affect spectroscopic measurements.
INTRODUCTION TO UV-VISIBLE SPECTROSCOPYJunaid Khan
UV-visible spectroscopy involves measuring the absorption of electromagnetic radiation in the ultraviolet-visible spectral region. When UV-VIS radiation interacts with molecules, it can cause electronic transitions between different energy levels. The absorption spectrum obtained plots absorbance against wavelength, showing characteristic absorption bands. The positions and intensities of these bands provide information about the molecular structure of the absorbing chemical species.
The document summarizes infrared (IR) spectroscopy, including its principle, instrumentation, applications, and interpretation of spectra. IR spectroscopy works by detecting the vibrational and rotational absorption frequencies of molecules when exposed to IR radiation. The spectrum produced provides information on molecular structure and bonding. Key regions of the IR spectrum correspond to common functional groups like C=O, N-H, and O-H. Analysis of peak positions and relative intensities allows identification of compounds and detection of impurities.
This document discusses different techniques for sampling solids in infrared spectroscopy. There are four main techniques: solids run in solution, solid films, the mull technique, and the pressed pellet technique. The mull technique involves grinding the solid sample with a mulling agent like mineral oil or nujol. The pressed pellet technique involves grinding the solid sample with potassium bromide and pressing it under high pressure to form a pellet. The mull and pellet techniques are commonly used as they eliminate interference from solvents or mulling agents and allow for qualitative and quantitative analysis. Proper sample preparation is important to obtain high quality infrared spectra of solid samples.
The document provides an overview of the history and development of spectroscopy, from Newton's discovery of the rainbow spectrum to modern applications across the electromagnetic spectrum. Key events and figures discussed include Kirchoff and Bunsen's establishment of spectroscopy and the development of new techniques in the 20th century that enabled analysis of different wavelength regions.
UV-VIS spectroscopy involves using ultraviolet or visible light to illuminate a sample and analyzing the light that is absorbed. Electronic transitions in molecules can be detected by observing which wavelengths of light are absorbed. This provides information about functional groups and conjugated systems present in the sample. A UV-VIS spectrophotometer directs light from a source through the sample solution and a monochromator selects wavelengths, which are then measured by a detector. The amount of light absorbed at each wavelength follows Beer's Law, allowing for determination of concentrations from a calibration curve.
1. Infrared spectroscopy analyzes molecular vibrations and rotations that occur when molecules absorb infrared radiation.
2. Different types of molecular vibrations like stretching and bending occur at characteristic frequencies that can identify functional groups and molecular structure.
3. The document discusses various spectroscopic techniques like fluorescence, X-ray, UV-Vis, IR, Raman, and NMR spectroscopy and their applications in chemistry.
This document provides an introduction to spectrometric methods and the Beer-Lambert law. It defines key terms like absorbance, transmittance, molar absorptivity, and wavelength. The Beer-Lambert law states that absorbance is directly proportional to concentration, path length, and molar absorptivity. It also explains that absorbance follows a linear relationship with concentration at a given path length and wavelength for a single analyte. Deviations from Beer's law can occur under certain circumstances.
The document discusses different types of tablets, their advantages and disadvantages, ingredients used in tablets including diluents, binders, disintegrants, lubricants and other excipients. It describes various commonly used excipients, their functions and provides examples. The document also covers different types of tablets based on how they are administered and how they are used.
Integration By Parts Tutorial & Example- Calculus 2empoweringminds
This document provides an overview of integration by parts. It states the basic formula as ∫udv = uv - ∫vdu and discusses when to let u = x^n, dv = x^n, and dv = e^ax. It provides example problems and reminds the reader to recall the integration by parts formula. The document concludes by wishing the reader the best in their mathematical endeavors and quoting Albert Einstein.
There are four main techniques used to prepare solid samples for IR spectroscopy: dissolving solids in solution, solid films, mull technique, and pressed pellet technique. The mull technique involves grinding the solid sample with a mulling agent like mineral oil or nujol to form a paste between IR windows. The pressed pellet technique uses potassium bromide to form a compressed pellet, avoiding interference from a mulling agent. Liquids can be analyzed directly in liquid sample cells of appropriate thickness.
Integration by parts is a technique for evaluating integrals of the form ∫udv, where u and v are differentiable functions. It works by expressing the integral as uv - ∫vdu. Some examples of integrals solved using integration by parts include ∫x cos x dx, ∫xe^x dx, and ∫ln x dx. Repeated integration by parts may be necessary when the integral ∫vdu produced is still difficult to evaluate. Integration by parts also applies to definite integrals between limits a and b using the formula ∫_a^b udv = [uv]_a^b - ∫_a^b vdu.
This document provides information about confocal microscopy. It discusses:
- How confocal microscopy works by excluding light from out-of-focus planes to generate high-contrast images with better resolution than conventional microscopes.
- The history of confocal microscopy, which was pioneered by Marvin Minsky in 1955 using pinholes and point-by-point illumination.
- Key aspects of confocal microscopy like using fluorophores, laser excitation, and building 3D images by combining thin optical sections.
Circular dichroism is the difference in absorption of left and right circularly polarized light by a chiral molecule. It occurs due to interactions between the molecule's chiral chromophores and polarized light. CD spectroscopy is used to analyze the secondary structure of proteins and monitor structural changes. The technique provides structural signatures for alpha helices, beta sheets, and random coils. It is a powerful tool for studying protein folding and structural changes under various conditions.
MALDI-TOF: Pricinple and Its Application in Biochemistry and BiotechnologyDevakumar Jain
The document discusses MALDI-TOF (matrix-assisted laser desorption/ionization time-of-flight) mass spectrometry. It provides a history of the development of mass spectrometry techniques. MALDI-TOF allows for the analysis of intact biomolecules like proteins and is a soft ionization method. It provides high sensitivity and mass accuracy for analyzing proteins, peptides, and other large biomolecules. The document also discusses applications of MALDI-TOF like protein identification and characterization.
This document provides an overview of ultraviolet-visible (UV-Vis) spectroscopy. It defines UV-Vis spectroscopy as the measurement of light absorption by a sample after it passes through or is reflected from the sample. The document outlines key components of UV-Vis spectroscopy including the absorption spectrum, types of electronic transitions that can occur, Beer's and Lambert's laws describing the relationship between absorbance and concentration, instrumentation components, and applications such as qualitative and quantitative analysis. Effects of chromophores, solvents, and auxochromes on absorption spectra are also discussed.
This document provides an overview of ultraviolet-visible spectroscopy. It defines UV-VIS spectroscopy and discusses the principle, instrumentation, and applications. Key points include:
1) UV-VIS spectroscopy measures the attenuation of light passing through a sample, allowing detection of electronic transitions in molecules from absorption measurements.
2) The absorption spectrum provides information on maximum wavelength of absorption and intensity. Instrumentation includes a light source, monochromator, sample holder, and detector.
3) Applications include qualitative and quantitative analysis of compounds, detection of functional groups and impurities, and determination of concentration. UV-VIS spectroscopy is useful for studying kinetics, tautomers, and inorganic compounds.
Seminar on Uv Visible spectroscopy by Amogh G VAmoghGV
PPT of seminar on UV Visible spectroscopy, electronic transitions, Instrumentation of Double beam spectrophotometers, Advantages of Double beam over single beam, Beer Lamberts law derivation
Ultraviolet-visible spectroscopy involves promoting electrons from the highest occupied molecular orbital to the lowest unoccupied molecular orbital when molecules absorb electromagnetic radiation. This causes different types of electronic transitions that can be observed based on wavelength shifts. The technique follows Beer's law where absorbance is directly proportional to concentration and path length. It is used to determine conjugation and identify functional groups in molecules.
Unit 5 Spectroscopic Techniques-converted (1) (1).pdfSurajShinde558909
Spectroscopy is the study of interaction of electromagnetic radiation with matter. Spectroscopic techniques are based on measurement of electromagnetic radiation emitted or absorbed by a sample. The main spectroscopic techniques discussed are UV-Visible spectroscopy and Infrared (IR) spectroscopy. UV-Visible spectroscopy provides information about double and triple bonds in molecules, while IR spectroscopy provides information about functional groups. Both techniques can be used for qualitative and quantitative analysis of compounds.
This document provides an overview of UV-visible spectroscopy. It discusses the basic principles including Beer's law and how UV spectroscopy can be used to analyze functional groups in molecules. The key components of a UV-visible spectrophotometer are described including radiation sources, monochromators, sample cells, and detectors. Common solvents used are also discussed along with how solvents can impact absorption spectra. In summary, UV-visible spectroscopy measures the absorption of UV and visible light by molecules and can be used to qualitatively and quantitatively analyze samples.
UV-Vis spectroscopy measures absorption of ultraviolet and visible light by molecules. It works on the principle of Beer-Lambert law, where absorption is directly proportional to concentration and path length of light through the sample. The instrument consists of a light source, monochromator, sample holder, and detector. Electronic transitions between molecular orbitals that can be detected by UV-Vis spectroscopy include σ-σ*, n-σ*, π-π*, and n-π* transitions. Sample preparation and choice of solvent are important factors to consider. UV-Vis spectroscopy has applications in qualitative and quantitative analysis, identification of compounds, and studying kinetics and equilibria.
The document provides an overview of UV-visible spectroscopy. It discusses how UV-visible spectroscopy works by measuring absorption or emission of electromagnetic radiation by molecules. It describes the instrumentation used in UV-visible spectroscopy including light sources, sample handling using cuvettes, and detectors. It also covers concepts like chromophores, transitions between molecular orbitals, and selection rules. Applications discussed include analysis of functional groups, determination of structure and configuration of compounds.
UV-visible spectroscopy measures the absorption of light in the ultraviolet-visible spectral region. It can be used to analyze concentration and interactions between molecules. The document discusses the history, basic principles, instrumentation, and applications of UV-visible spectroscopy. It provides details on electronic transitions, Beer's law, components of UV-visible spectrometers including light sources, wavelength selectors, sample holders, detectors, and the differences between single and double beam instruments.
UV-visible spectroscopy is a technique that uses light in the visible and adjacent ranges. It works by measuring how much light is absorbed by a sample at each wavelength.
The document discusses the basic principles of spectroscopy including the laws of absorption. It describes the instrumentation used in UV-visible spectroscopy including light sources, wavelength selectors, sample holders and detection devices.
The document also covers electronic transitions that can occur, different types of spectrometers, and applications of UV-visible spectroscopy in chemistry, physics and other fields.
This document provides an overview of UV-visible spectroscopy. It discusses the electromagnetic spectrum and how UV-visible spectroscopy involves absorption of UV or visible light by molecules, promoting electrons to excited states. Beer-Lambert's law describes the relationship between light absorption and analyte concentration. Chromophores and auxochromes determine peak absorption wavelengths. Factors like pH and solvents affect absorption spectra. UV-visible spectroscopy has applications in determining molecular structures, concentrations, and impurities. Instrumentation includes sources like hydrogen lamps, monochromators, sample holders, detectors like photomultiplier tubes, and single or double beam spectrophotometers.
This document provides an overview of UV-Visible spectroscopy. It discusses the basic principles including electromagnetic radiation, spectroscopy, absorption of UV-Visible light, and Beer-Lambert's law. It describes the instrumentation of UV-Visible spectroscopy including light sources, wavelength selectors, sample compartments, detectors and basic components. It also discusses electronic transitions, shifts in absorption, and applications of UV-Visible spectroscopy in qualitative and quantitative analysis.
UV - Visible Spectroscopy detailed information is included .The Spectroscopy study provide the information and the absorbance as well the concentration of the drugs is studied.
uv spectelectronic transition in the roscopyRiyaDas765755
This document discusses UV spectroscopy and instrumentation. It provides an overview of electronic transitions including σ→ σ*, n → σ*, π→ π*, and n → π* transitions. It describes the basic components of UV-visible spectrophotometers including light sources, wavelength selectors, sample holders, detectors, and the differences between single beam and double beam instruments. The conclusion states that UV spectroscopy is routinely used in analytical chemistry for quantitative analysis of transition metals, conjugated organics, and biomolecules, and instrumentation enables precise measurements and enhanced capabilities.
This document provides an overview of UV-visible spectroscopy. It discusses the history and development of UV-visible spectrometers. It explains that UV-visible spectroscopy involves measuring the absorption of UV or visible light by a sample. This can provide information about molecular structure through electronic transitions. The document also outlines the Beer-Lambert law and how it relates absorbance to concentration. It describes instrumentation components and electronic transitions involved. Applications like detection of impurities and structure elucidation are also mentioned.
This document provides an overview of UV spectroscopy. It discusses electronic transitions that occur in the UV region, including σ → σ*, n → σ*, n → π*, and π → π* transitions. Selection rules that determine observable transitions are also covered. The Beer-Lambert law relating absorbance to concentration is introduced. Instrumentation for UV spectroscopy including various light sources, monochromators, and detectors is described.
UV Visible Spectroscopy involves the study of interaction between electromagnetic radiation and matter. It is used to measure absorption or transmission of light passing through a sample. The technique utilizes wavelengths in the UV and visible range from 200-800 nm. Key aspects covered include Beer's law, electronic transitions involved, instrumentation components, and applications such as determining impurities, functional groups, and drug assay.
UV-Visible Spectrometry is a technique used to analyze how molecules interact with light in the UV-Visible region. It works based on Beer's Law, where the absorbance of a solution is directly proportional to concentration and path length. The key components of a UV-Vis spectrometer are a radiation source, monochromator, sample cells, and detectors. It can be used for structure elucidation, quantitative analysis, detection of impurities, and studying chemical kinetics. Larger conjugated systems absorb at longer wavelengths with higher intensities. Solvents and functional groups can also impact absorption spectra.
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This presentation includes basic of PCOS their pathology and treatment and also Ayurveda correlation of PCOS and Ayurvedic line of treatment mentioned in classics.
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Chapter wise All Notes of First year Basic Civil Engineering.pptxDenish Jangid
Chapter wise All Notes of First year Basic Civil Engineering
Syllabus
Chapter-1
Introduction to objective, scope and outcome the subject
Chapter 2
Introduction: Scope and Specialization of Civil Engineering, Role of civil Engineer in Society, Impact of infrastructural development on economy of country.
Chapter 3
Surveying: Object Principles & Types of Surveying; Site Plans, Plans & Maps; Scales & Unit of different Measurements.
Linear Measurements: Instruments used. Linear Measurement by Tape, Ranging out Survey Lines and overcoming Obstructions; Measurements on sloping ground; Tape corrections, conventional symbols. Angular Measurements: Instruments used; Introduction to Compass Surveying, Bearings and Longitude & Latitude of a Line, Introduction to total station.
Levelling: Instrument used Object of levelling, Methods of levelling in brief, and Contour maps.
Chapter 4
Buildings: Selection of site for Buildings, Layout of Building Plan, Types of buildings, Plinth area, carpet area, floor space index, Introduction to building byelaws, concept of sun light & ventilation. Components of Buildings & their functions, Basic concept of R.C.C., Introduction to types of foundation
Chapter 5
Transportation: Introduction to Transportation Engineering; Traffic and Road Safety: Types and Characteristics of Various Modes of Transportation; Various Road Traffic Signs, Causes of Accidents and Road Safety Measures.
Chapter 6
Environmental Engineering: Environmental Pollution, Environmental Acts and Regulations, Functional Concepts of Ecology, Basics of Species, Biodiversity, Ecosystem, Hydrological Cycle; Chemical Cycles: Carbon, Nitrogen & Phosphorus; Energy Flow in Ecosystems.
Water Pollution: Water Quality standards, Introduction to Treatment & Disposal of Waste Water. Reuse and Saving of Water, Rain Water Harvesting. Solid Waste Management: Classification of Solid Waste, Collection, Transportation and Disposal of Solid. Recycling of Solid Waste: Energy Recovery, Sanitary Landfill, On-Site Sanitation. Air & Noise Pollution: Primary and Secondary air pollutants, Harmful effects of Air Pollution, Control of Air Pollution. . Noise Pollution Harmful Effects of noise pollution, control of noise pollution, Global warming & Climate Change, Ozone depletion, Greenhouse effect
Text Books:
1. Palancharmy, Basic Civil Engineering, McGraw Hill publishers.
2. Satheesh Gopi, Basic Civil Engineering, Pearson Publishers.
3. Ketki Rangwala Dalal, Essentials of Civil Engineering, Charotar Publishing House.
4. BCP, Surveying volume 1
1. Presentation topic –
Ultra-violate spectroscopy
Submitted by –
Moriyom Akhter
Md Shah Alam
Department of pharmacy
World university of Bangladesh
2. DEFINITION
UV RADIATION
PRINCIPLE OF UV-VIS SPECTROMETRY
THE ABSORPTION SPECTRUM
TYPES OF TRANSITIONS
ABSORBANCE LAWS
INSTRUMENTATION
EFFECT OF CHROMOPHORE
WOODWARD-FEISER RULE
SOLVENT EFFECTS
APPLICATIONS
3. Ultraviolet and visible (UV-Vis)
absorption
spectroscopy
is
the
measurement of the attenuation of a
beam of light after it passes through a
sample or after reflection from a sample
surface. Absorption measurements can
be at a single wavelength or over an
extended spectral range.
4. 1.
2.
3.
4.
5.
6.
7.
Detection of functional groups.
Detection of impurities
Qualitative analysis
Quantitative analysis
Single compound without chromophore
Drugs with chromophoric reagent
It is helps to show the relationship
between different groups, it is useful to
detect the conjugation of the compounds
5. The region beyond red is called infra-red while
that beyond violet is called as ultra –violet. The
wavelength range of uv radiation starts at blue
end of visible light(4000A) & ends at 2000A.
̊
6.
Ultraviolet absorption spectra arise from transition of electron with in a molecule from a lower level to a
higher level.
A molecule absorb ultraviolet radiation of frequency (𝜗), the electron in that molecule undergo transition
from lower to higher energy level.
The energy can be calculated by the equation,
E=h𝜗 erg
8. Thus the energy of the radiation in the visible range is generally: 36 to 72 kcal/mole while that
in the ultraviolet range goes as high as 143 kcal/mole
9. When a sample is exposed to light energy that matches
the energy difference between a possible electronic
transition within the molecule, a fraction of the light energy
would be absorbed by the molecule and the electrons
would be promoted to the higher energy state orbital. A
spectrometer records the degree of absorption by a
sample at different wavelengths and the resulting plot of
absorbance (A) versus wavelength (λ) is known as a
spectrum.
The significant features:
λmax (wavelength at which there is a maximum
absorption)
єmax (The intensity of maximum absorption)
12. Every time a molecule has a bond, the atoms in a
bond have their atomic orbitals merged to form
molecular orbitals which can be occupied by
electrons of different energy levels. Ground state
molecular orbitals can be excited to anti-bonding
molecular orbitals.
These electrons when imparted with energy in the
form of light radiation get excited from the highest
occupied molecular orbital (HOMO) to the lowest
unoccupied molecular orbital (LUMO) and the
resulting species is known as the excited state or
anti-bonding state.
13. TYPES OF TRANSITIONS:
In U.V spectroscopy molecule undergo
electronic transition involving σ, π and n
electrons.
Four types of electronic transition are
possible.
i. σ ⇾ σ* transition
ii. n ⇾ σ* transition
iii. n ⇾ π* transition
iv. π ⇾ π* transition
13
14. An electron in a bonding σ orbital of a molecule
is excited to the corresponding anti-bonding
orbital by the absorption of radiation.
To induce a σ ⇾ σ* transition it required LARGE
ENERGY.
Ex: Methane
Methane contain only single C-H bonds it undergo
only σ ⇾ σ* transition only, it gives absorption
maximum at 125nm.
15. In this type saturated compounds containing atoms
with unshared electron pairs are undergo n ⇾ σ*
transition.
It require less energy than the σ ⇾ σ* type.
Most of the absorption peaks appearing below
200nm.
In the presence of polar solvents the absorption
maximum tend to shift shorter wavelength
Ex: Water , ethanol.
In this the peaks in U.V region relatively small.
Ex: Methlychloried , Oxygen, Nitrogen.
16. Most organic compounds are undergo transitions
for n ⇾ π* and π ⇾ π* transition.
Because energies required for processes bring
the absorption peaks into spectral region.
Both transition require the presence of an
unsaturated functional group to the ´∏´ orbitals.
Ex: For π ⇾ π* ⧐ Alkenes,
compounds, alkynes
carbonyl
For n ⇾ π* ⧐ carbonyl compounds.
17. σ∗ (anti-bonding)
Four types of transitions
π∗ (anti-bonding)
σ→σ*
n (non-bonding)
π→π*
n→σ*
π (bonding)
σ (bonding)
n→π*
18. ABSORBANCE LAWS
BEER’S LAW
“ The intensity of a beam of monochromatic light
decrease exponentially with the increase in concentration
of the absorbing substance” .
Arithmetically;
- dI/ dc ᾱ I
I= Io. eˉkc --------------------------eq (1)
19. LAMBERT’S LAW
“ When a beam of light is allowed to pass through a
transparent medium, the rate of decrease of
intensity with the thickness of medium is directly
proportional to the intensity of the light”
mathematically;
-dI/ dt ᾱ I
-In . I = kt+b ----------------eq(2)
the combination of eq 1 & 2 we will get
A= Kct
A= ℇct
(K=ℇ)
20. LIMITATION OF LAWS
The real limitation of the beer’s law is successfully
in describing the absorption behavior of dilute
solution only.
In this regarding it may be considered as a
limiting law.
As degree of interaction depends upon the
contraction, the occurrence of this phenomenon
causes deviations from linear relationship
between absorbance and contraction.
24. It is important that the power of the radiation source does
not change abruptly over its wavelength range. The
electrical excitation of deuterium or hydrogen at low
pressure produces a continuous UV spectrum.
Both Deuterium and Hydrogen lamps emit radiation in
the range 160 - 375 nm.
Problem
Due to evaporation of tungsten life period decreases.
It is overcome by using tungsten-halogen lamp.
Halogen gas prevents evaporation of tungsten.
25. For ultra violet regionHydrogen discharge lamp
consist of two electrode contain in deuterium filled silica
envelop.
UV-Vis spectrophotometer have both deuterium & tungsten
lamps.
Selection of lamp is made by moving lamp mounting or
mirror to cause the light fall on Monochromator.
Deuterium lamps: Radiation emitted is 3-5 times more than the hydrogen
discharge lamps.
Xenon discharge lamp: Xenon stored under pressure in 10-30 atmosphere.
26. All Monochromators contain the following component parts;
• An entrance slit
• A collimating lens
• A dispersing device (a prism or a grating)
• A focusing lens
• An exit slit
27. Filters –
a)Glass filters- Made from pieces of colored glass which
transmit limited wave length range of spectrum. Wide band
width 150nm.
b)Gelatin filters- Consist of mixture of dyes placed in gelatin
& sandwiched between glass plates. Band width 25nm.
c)Inter ferometric filters- Band width 15nm
Prisms-Prism bends the monochromatic light.
-Amount of deviation depends on wavelength
-They produce non linear dispersion.
29. A variety of sample cells available for UV region. The
choice of sample cell is based on
a) the path length, shape, size
b) the transmission characteristics at the desired
wavelength
c) the relative expense
The cell holding the sample should be transparent to the
wavelength region to be recorded. Quartz or fused silica
cuvettes are required for spectroscopy in the UV region.
Silicate glasses can be used for the manufacture of
cuvettes for use between 350 and 2000nm. The
thickness of the cell is generally 1 cm. cells may be
rectangular in shape or cylindrical with flat ends.
30.
31. Three common types of detectors are used
I. Barrier layer cell
II. Photo cell detector
III. Photomultiplier , Photo voltaic cells
barrier layer cells
It consist of flat Cu or Fe electrode on which semiconductor such
as selenium is deposited. on the selenium a thin layer of silver or
gold is sputtered over the surface.
32.
Photomultiplier tube
It is generally used as detector in UV- spectrophotometer It is the
combination of photodiode & electron multiplier.
It consist of evacuated tube contains photo- cathode. 9-16 electrodes
known as dynodes.
33.
34. I0
log(I0/I) = A
I
200
I0
detector
monochromator/
beam splitter optics
I0
referenc
e
UV-VIS sources
sample
Advantage of double beam spectrophotometer:- It is not necessary to
continually replace the blank with the sample or to adjust the auto zero.
The ratio of the powers of the sample & reference is constantly obtained.
It has rapid scanning over the wide wavelength region because of the
above two factors.
λ, nm
37. Any Functional group which is
responsible for impairing colour to the
compound is called as chromophore.
Ex: NO2
Covalently unsaturated groups
responsible for the impairing of the
colures.
Ex: C=C, C=O
Two types of chromophore
a) Independent
chromophore
b) dependent chromophore
39. It is the group which itself does not act as a
chromophore but when attached to chromophore it shifts
the absorption maximum towards longer wavelength
along with an increase in intensity of adsorption.
Ex: -OH, -NH2, -OR groups
For example when the auxochrome –NH2 is attached to
the benzene ring, it absorption changes from λmax 255
to 280nm.
TYPES
Two types
a. Bathochromic groups
b. Hypsochromic group
40. BATHOCHROMIC GROUPS
Those groups which deepen the colour of
chromogen are called bathochromic groups.
Deepening of colour means displacement
to longer wavelength.
yellow⇾ orange ⇾ red ⇾ purple ⇾
violet⇾ blue ⇾ green
41. Those groups which diminish or lighten the colour of the chromogen
are called hypsochromic groups.
They cause displacement to shorter wavelength.
Ex:- acetylation of –OH or –NH2 groups,
-OCOCH3 and –
NHCOCH3
Hyperchromic
ε
Bathochromic
Hypsochromic
Hypochromic
200 nm
700 nm
42. It is used for calculating the absorption maxima
Woodward (1941) gives certain rule for correlating λmax with the
molecular structure
This rule for calculating λmax in conjugated dienes, trienes, polyenes.
Homoannular dienes:cyclic dienes having conjugated double bonds in the same ring.
e.g.
CH3
CH3
47. SOLVENT EFFECTS - INTENSITY
Solvents can induce significant changes in the intensity of peaks.
Hyperchromic – Increase in absorption intensity.
Hypochromic – Decrease in absorption intensity.
Absorption characteristics of 2-methylpyridine
λmax
εmax
Hexane
260
2000
Chloroform
263
4500
Ethanol
260
4000
Water
260
4000
Solvent
Ethanol - HCl (1:1)
262
5200
48.
π -> π* transitions leads to more polar excited state that is more easily
stabilized by polar solvent associations (H-bonds). The π* state is more polar
and stabilized more in polar solvent relative to nonpolar one, thus in going
from nonpolar to polar solvent there is a red shift or bathochromic shift
(increase in λmax, decrease in ΔE).
For n -> π* transition, the n state is much more easily stabilized by polar
solvent effects (H-bonds and association), so in going from nonpolar to polar
solvent there is a blue shift or hypsochromic shift (decrease in λmax, increase in
ΔE).
49. APPLICATIONS:
A.
APPLICATIONS IN ORGANIC COMPOUNDS
1.It is helps to show the relationship between different groups, it is useful to
detect the conjugation of the compounds
2.Detection of geometrical isomers, In case of geometrical isomers compounds,
that trans isomers exhibits λmax at slightly longer wavelength and have larger
extinction coefficient then the cis isomers .
3.Detection of functional groups, it is possible to detect the presence of certain
functional groups with the help of UV Spectrum.
GENERAL APPLICATIONS:
1.Qualitative analysis, UV absorption spectroscopy can characterizes those type of
compounds which absorb UV radiation. Identification is done by comparing the
absorption spectrum with the spectra of known compound.
2. It is useful in Quantitative analysis of the compounds.
3. Detection of impurities, UV absorption spectroscopy is the one of the best
method for detecting impurities in organic compounds.
50. Tautomeric equilibrium, UV spectroscopy can be used to determine the
percentage of various keto and enol forms present in tautomeric equilibrium.
5. Chemical kinetics, UV spectroscopy can be used to study the kinetics of
reactions.
6. Molecular weight determination, molecular weights of compounds can be
measured by spectroscopy.
7. Analysis of inorganic compounds.
8. Measuring concentration of solution, absorption band can also used to
determine the concentration of compounds in a solution.
9. Inorganic chemistry, absorption spectra have been used in connection with
many problems in inorganic chemistry.
10. It is useful to determine the structure of the chloral.
51. QUALITATIVE ANALYSIS
Pharmacopoeial identification of drug
(1) By using absorbance & wavelength
(2) By taking absorption ratio
(3) Limit test (b)Structural analysis
Quantitative analysis
Quantitative analysis A)By using beer’s law and using absorptivity value By using
reference standard Multiple standard method
B)Single compound analysis direct analysis Using separation method After
extraction after chromatographic separation Using column chromatography Using
HPLC
Indirect analysis
a)Single compound without chromophore
b) Drugs with chromophoric reagent
1.For analyte which absorb weakly in UV region
2.For avoiding interference
52. 3.Improve selectivity of assay
4. Determination of composition of complex Mole ratio method Continuous
variation method ( job curve method )
5 . Study of kinetics
Disadvantages:
Samples should be in solution. Mixture of substances poses difficult to
analyse and requires prior separation.
Interference from the sample’s matrix makes the measurement difficult .