SPECTROSCOPY
UV-VISIBLE SPECTROSCOPY
PRINCIPLE
THEORY
LAWS
LAMBERT LAW
BEER'S LAW
LAMBERT BEER LAW
ABSORPTION & Intensity SHIFTS
WOODWARD-FIESCER RULE WITH EXAMPLES
INSTRUMENTATION (DETAILED)
CHOICE OF SOLVENT
SOLVENT EFFECT
EFFECT OF CONCENTRATION, TEMPERATURE & 푝퐻
ADVANTAGES & DISADVANTAGES
APPLICATIONS
REFERENCE
Solvents and solvent effect in UV - Vis Spectroscopy, By Dr. Umesh Kumar sh...Dr. UMESH KUMAR SHARMA
This document discusses solvent effects on UV-visible spectroscopy. It begins by explaining that UV spectra are usually measured in dilute solutions using solvents that are transparent in the wavelength range and do not interact strongly with the solute. Common solvents mentioned are ethanol, hexane, and water. The document then discusses various solvent effects including bathochromic shifts, hypsochromic shifts, hyperchromic shifts, and hypochromic shifts. It provides examples of how solvents can alter absorption wavelengths and intensities. The document concludes by mentioning several reference texts on this topic.
This document discusses instrumental techniques of analysis, specifically visible and ultraviolet spectroscopy. It covers the basic theory of spectroscopy and how matter interacts with electromagnetic radiation. Key points include:
1. Spectroscopy involves studying the interaction of matter with electromagnetic radiation like light.
2. UV-visible spectroscopy measures absorption of samples when electrons are excited from ground state to excited state.
3. Beer's law and Lambert's law describe the relationship between absorbance, concentration, and path length of samples.
4. The combined Beer-Lambert law states absorbance is directly proportional to concentration and path length of the absorbing species.
The document discusses UV-Visible spectroscopy. It begins by introducing the principles of spectroscopy and UV-Visible spectroscopy. It then covers various concepts related to UV-Visible spectroscopy including electronic transitions, absorption and intensity shifts, Beer's law, instrumentation, choice of solvent, and applications. The key components of a UV-Visible spectrophotometer are described including the light source, monochromator, sample holder, and detector. Common types of light sources and monochromators such as filters, prisms and gratings are also discussed.
Polymer-drug conjugates are a novel class of nanocarriers for drug delivery, which can protect the drug from premature degradation, prevent the drug from premature interaction with the biological environment and enhance the absorption of the drugs into tissues (by enhanced permeability and retention effect or active targeting).
Polymer-drug conjugates are often considered as new chemical entities (NCEs) owing to a distinct pharmacokinetic profile from that of the parent drug.
Conjugation of a drug with a polymer forms so-called ‘Polymeric Prodrug’.
This document discusses various types of nanoparticles including their properties, preparation, and applications. It describes carbon-based nanoparticles like carbon nanotubes, solid-lipid nanoparticles, silicon-based nanoparticles, liposomes, nanosomes, and niosomes. Nanoparticles have sizes between 1-100 nanometers and unique optical, magnetic, mechanical, and thermal properties dependent on their size and structure. They are useful for drug and gene delivery, cancer therapy, and other medical applications due to properties like cell specificity and reduced toxicity.
The document discusses ocular drug delivery and barriers to drug permeation in the eye. It describes the anatomy of the eye and mechanisms of drug absorption through corneal and non-corneal routes. The major barriers to ocular drug delivery are precorneal drainage, blinking, lacrimation, and barriers posed by the cornea, conjunctiva, sclera, blood-ocular barriers, and physiological factors. Methods to overcome these barriers include alternative delivery routes like intravitreal injections and novel drug delivery systems providing controlled release and improved permeability. Conventional systems like solutions, suspensions, and ointments have limitations like poor bioavailability and frequent dosing that novel particulate and vesicular systems aim to address.
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 discusses different types of rate-controlled drug delivery systems. It begins with an introduction to sustained and controlled release drug delivery. There are three main types of rate-controlled systems: rate preprogrammed systems where the drug release rate is predetermined; activation-modulated systems where a stimulus triggers drug release; and feedback-regulated systems where a sensor detects drug levels and modulates release accordingly. Specific examples like transdermal patches are provided for each system type. Drug release rates are controlled by factors like membrane permeability, polymer solubility, and drug diffusivity.
Solvents and solvent effect in UV - Vis Spectroscopy, By Dr. Umesh Kumar sh...Dr. UMESH KUMAR SHARMA
This document discusses solvent effects on UV-visible spectroscopy. It begins by explaining that UV spectra are usually measured in dilute solutions using solvents that are transparent in the wavelength range and do not interact strongly with the solute. Common solvents mentioned are ethanol, hexane, and water. The document then discusses various solvent effects including bathochromic shifts, hypsochromic shifts, hyperchromic shifts, and hypochromic shifts. It provides examples of how solvents can alter absorption wavelengths and intensities. The document concludes by mentioning several reference texts on this topic.
This document discusses instrumental techniques of analysis, specifically visible and ultraviolet spectroscopy. It covers the basic theory of spectroscopy and how matter interacts with electromagnetic radiation. Key points include:
1. Spectroscopy involves studying the interaction of matter with electromagnetic radiation like light.
2. UV-visible spectroscopy measures absorption of samples when electrons are excited from ground state to excited state.
3. Beer's law and Lambert's law describe the relationship between absorbance, concentration, and path length of samples.
4. The combined Beer-Lambert law states absorbance is directly proportional to concentration and path length of the absorbing species.
The document discusses UV-Visible spectroscopy. It begins by introducing the principles of spectroscopy and UV-Visible spectroscopy. It then covers various concepts related to UV-Visible spectroscopy including electronic transitions, absorption and intensity shifts, Beer's law, instrumentation, choice of solvent, and applications. The key components of a UV-Visible spectrophotometer are described including the light source, monochromator, sample holder, and detector. Common types of light sources and monochromators such as filters, prisms and gratings are also discussed.
Polymer-drug conjugates are a novel class of nanocarriers for drug delivery, which can protect the drug from premature degradation, prevent the drug from premature interaction with the biological environment and enhance the absorption of the drugs into tissues (by enhanced permeability and retention effect or active targeting).
Polymer-drug conjugates are often considered as new chemical entities (NCEs) owing to a distinct pharmacokinetic profile from that of the parent drug.
Conjugation of a drug with a polymer forms so-called ‘Polymeric Prodrug’.
This document discusses various types of nanoparticles including their properties, preparation, and applications. It describes carbon-based nanoparticles like carbon nanotubes, solid-lipid nanoparticles, silicon-based nanoparticles, liposomes, nanosomes, and niosomes. Nanoparticles have sizes between 1-100 nanometers and unique optical, magnetic, mechanical, and thermal properties dependent on their size and structure. They are useful for drug and gene delivery, cancer therapy, and other medical applications due to properties like cell specificity and reduced toxicity.
The document discusses ocular drug delivery and barriers to drug permeation in the eye. It describes the anatomy of the eye and mechanisms of drug absorption through corneal and non-corneal routes. The major barriers to ocular drug delivery are precorneal drainage, blinking, lacrimation, and barriers posed by the cornea, conjunctiva, sclera, blood-ocular barriers, and physiological factors. Methods to overcome these barriers include alternative delivery routes like intravitreal injections and novel drug delivery systems providing controlled release and improved permeability. Conventional systems like solutions, suspensions, and ointments have limitations like poor bioavailability and frequent dosing that novel particulate and vesicular systems aim to address.
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 discusses different types of rate-controlled drug delivery systems. It begins with an introduction to sustained and controlled release drug delivery. There are three main types of rate-controlled systems: rate preprogrammed systems where the drug release rate is predetermined; activation-modulated systems where a stimulus triggers drug release; and feedback-regulated systems where a sensor detects drug levels and modulates release accordingly. Specific examples like transdermal patches are provided for each system type. Drug release rates are controlled by factors like membrane permeability, polymer solubility, and drug diffusivity.
Introduction to UV spectroscopy, Instrumentation, electronic excitation and terms used. Absorption and intensity shifts, factors affecting position and intensity of UV bands, applications.
This document discusses bioadhesion, providing an introduction, theories, fundamentals and models. It defines bioadhesion as adhesion between biological materials, with mucoadhesion being adhesion to mucosal membranes. Theories of bioadhesion include wetting, diffusion, electronic, fracture and adsorption. Fundamentals discussed are biological membranes, bioadhesive polymers and modulation of mucoadhesion. Models of measuring bioadhesion described include falling liquid film, USP apparatus 4 and ex vivo methods. The conclusion states bioadhesion can facilitate adhesion of cells and biomolecules to develop novel biomaterials and therapies.
UV-visible spectroscopy is a fast analytical technique that measures the absorbance or transmittance of light. Although the UV wavelength ranges from 100–380 nm and the visible component goes up to 800 nm, most of the spectrophotometers have a working wavelength range between 200–1100 nm.
The practical range for UV-vis spectroscopy varies from 200–800 nm; above 800 nm is infrared, while below 200 nm is known as vacuum UV. The ability of matter to absorb and to emit light is what defines its color and the human eye is capable of differentiating up to 10 million unique colors. Light passes through media (transmission), reflects off both opaque and transparent surfaces, and is refracted by crystals. Covalently unsaturated compounds with electronic transition energy differences equivalent to the energy of the UV-visible light absorb at specific wavelengths. These compounds are known as chromophores and are responsible for their color. Covalently saturated groups that do not absorb UV-visible electromagnetic radiation but affect the absorption of chromophore groups are called auxochromes. When UV-vis radiation hits chromophores, electrons in the ground state jump to an excited state, which we refer to as electron-excitation, while auxochromes are electron-donating and have the capacity to affect the color of choromophores while they do not change color themselves. Water and alcohols are mostly transparent and do not absorb in the UV-vis range and so are excellent mediums for UV-visible spectroscopy. Acetone and dimethylformamide (DMF) are good solvents for compounds insoluble in water and alcohol, but they absorb light below 320 and 275 nm, respectively, so are appropriate only above these cut-off wavelengths.
X-Ray Crystallography and Derivation of Braggs's lawShihabPatel
This document provides an overview of x-ray diffraction, including how x-rays are produced, Bragg's law which describes x-ray diffraction, different x-ray diffraction methods like rotating crystal technique and powder diffraction, types of crystals, and applications of x-ray diffraction like material identification and particle size determination. It contains sections on the production of x-rays, Bragg's law, rotating crystal technique, x-ray powder diffraction, types of crystals, and applications of x-ray diffraction.
Introduction,Instrumentation, Classification of electronic transitions, Substituent and solvent effects, Classification of electronic transitions
Substituent and solvent effects
Applications of UV Spectroscopy
UV spectral study of alkenes
UV spectral study of poylenes
UV spectral study of α, β-unsaturated carbonyl
UV spectral study of Aromatic compounds
Empirical rules for calculating λmax.
Applications of UV Spectroscopy, Empirical rules for calculating λmax.
Spectrofluorimetry uses fluorescence to analyze samples. Fluorescence occurs when molecules absorb ultraviolet or visible light then emit light at a higher wavelength. A spectrofluorimeter contains a light source, monochromators to isolate wavelengths, and a detector. It can quantify substances like vitamins, drugs, proteins, and more down to attogram levels. Though specific, fluorescence can be impacted by environmental factors and some compounds may not fluoresce. Areas of application include chemistry, biochemistry, medicine, and more.
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.
This document provides an overview of proton NMR spectroscopy. It begins with definitions of light and the electromagnetic spectrum. It then discusses spectroscopy in general and introduces NMR, focusing on proton NMR. The key concepts of proton NMR covered include its principle, instrumentation, chemical shifts, spin-spin splitting, deuterium exchange, and the n+1 rule. Applications discussed include distinguishing isomers, determining molecular weight, and studying tautomeric mixtures. Clinical, agricultural, and biological applications are also mentioned.
Ultraviolet–visible spectroscopy or ultraviolet-visible spectrophotometry (UV-Vis or UV/Vis) refers to absorption spectroscopy or reflectance spectroscopy in the ultraviolet-visible spectral region. This means it uses light in the visible and adjacent ranges.
Ion exchange chromatography uses ion exchange resins to separate mixtures of similarly charged ions through reversible ion exchange. There are four main types of resins classified by their chemical nature: strong cation, weak cation, strong anion, and weak anion exchange resins. Ion exchange resins must be chemically stable, insoluble in solvents, sufficiently cross-linked, and denser than water while containing ion exchange groups. Factors like the nature and properties of resins, exchanging ions, solution concentration, and charge impact ion exchange separations. Ion exchange chromatography has applications like water softening, demineralization, purification of solutions, separation of inorganic/organic ions, and use in HPLC columns.
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
UV/visible spectroscopy involves using electromagnetic radiation in the UV and visible light range to analyze samples. Key principles are that different functional groups and molecular structures absorb radiation at characteristic wavelengths. Absorption of light causes electronic transitions between molecular orbitals. The Beer-Lambert law states that absorbance is directly proportional to concentration, with molar absorptivity coefficients describing this relationship. Absorption spectra provide information to identify compounds and determine concentrations.
uv spectroscopy by HARVINDAR SINGH .M.PHARM PHARMACEUTICSHarevindarsingh
Ultraviolet-visible spectroscopy involves using UV or visible light to analyze samples. It works by measuring the absorption spectrum of a sample after passing light through it. The spectrum produced can be used to determine characteristics about the sample like its structure or concentration. Common applications of UV-Vis spectroscopy include identifying functional groups, determining the extent of conjugation, and elucidating unknown molecular structures.
spectrofluorometer is the instrument for recording fluorescence emission and absorption spectra When a beam of light is incident on certain substances they emit visible light or radiations. This is known as fluorescence. Fluorescence starts immediately after the absorption of light and stops as soon as the incident light is cut off. The substances showing this phenomenon are known as flourescent substances.
The coupling constant is the distance between peaks in a multiplet in NMR spectroscopy. It is measured in Hertz and does not depend on external magnetic field strength. The value of the coupling constant provides information to distinguish multiplets and can indicate structural features like cis/trans isomers. Coupling occurs between protons close in space, known as geminal, vicinal, and sometimes long-range coupling over several bonds. The coupling constant is affected by factors like bond angle, dihedral angle, and electronegativity of substituents.
X- ray crystallography, Shriyansh Srivastava, M.Pharm (Department of Pharmaco...Shriyansh Srivastav
X-ray crystallography uses X-rays to determine the atomic and molecular structure of crystals. Wilhelm Röntgen discovered X-rays in 1895. X-rays are produced when high velocity electrons collide with a metal target. X-ray crystallography works by firing a beam of X-rays at crystalline solids and observing the diffraction pattern of scattered X-rays. Bragg's law describes the conditions under which constructive interference of X-rays occurs and can be used to determine crystal structures. Common methods include rotating crystal, powder diffraction, and using detectors like photographic film, Geiger-Müller counters, or scintillation counters. X-ray crystallography has applications in determining protein structures and identifying
SPECTROSCOPY
INFRARED SPECTROSCOPY
HISTORY
PRINCIPLE
MODES OF VIBRATION
INSTRUMENTATION
SAMPLE HANDLING
FTIR (FOURIER TRANSFORM INFRARED) SPECTROMETER
PRINCIPLE
INSTRUMENTATION
WORKING
DISPERSIVE VERSUS FTIR
ADVANTAGES & DISADVANTAGES OF FTIR WITH APPLICATIONS
FACTORS AFFECTING VIBRATIONAL FREQUENCIES
IR SPECTRA REGION
IR SPECTRA INTERPRETATION
EXAMPLES
ADVANTAGES AND DISADVANTAGES OF IR
APPLICATIONS OF IR
Reference
The document provides an overview of mass spectrometry. It discusses the history, principles, instrumentation, ionization techniques, mass analyzers, and applications of mass spectrometry. Mass spectrometry involves converting sample molecules to ions, separating the ions based on their mass-to-charge ratio, and detecting the ions. Key components include an ion source, mass analyzer, and ion detector. Common ionization methods include electron ionization and chemical ionization. Common mass analyzers are magnetic sector, quadrupole, time-of-flight, and ion trap. Mass spectrometry has various applications in fields like proteomics, metabolomics, and environmental analysis.
Introduction to UV spectroscopy, Instrumentation, electronic excitation and terms used. Absorption and intensity shifts, factors affecting position and intensity of UV bands, applications.
This document discusses bioadhesion, providing an introduction, theories, fundamentals and models. It defines bioadhesion as adhesion between biological materials, with mucoadhesion being adhesion to mucosal membranes. Theories of bioadhesion include wetting, diffusion, electronic, fracture and adsorption. Fundamentals discussed are biological membranes, bioadhesive polymers and modulation of mucoadhesion. Models of measuring bioadhesion described include falling liquid film, USP apparatus 4 and ex vivo methods. The conclusion states bioadhesion can facilitate adhesion of cells and biomolecules to develop novel biomaterials and therapies.
UV-visible spectroscopy is a fast analytical technique that measures the absorbance or transmittance of light. Although the UV wavelength ranges from 100–380 nm and the visible component goes up to 800 nm, most of the spectrophotometers have a working wavelength range between 200–1100 nm.
The practical range for UV-vis spectroscopy varies from 200–800 nm; above 800 nm is infrared, while below 200 nm is known as vacuum UV. The ability of matter to absorb and to emit light is what defines its color and the human eye is capable of differentiating up to 10 million unique colors. Light passes through media (transmission), reflects off both opaque and transparent surfaces, and is refracted by crystals. Covalently unsaturated compounds with electronic transition energy differences equivalent to the energy of the UV-visible light absorb at specific wavelengths. These compounds are known as chromophores and are responsible for their color. Covalently saturated groups that do not absorb UV-visible electromagnetic radiation but affect the absorption of chromophore groups are called auxochromes. When UV-vis radiation hits chromophores, electrons in the ground state jump to an excited state, which we refer to as electron-excitation, while auxochromes are electron-donating and have the capacity to affect the color of choromophores while they do not change color themselves. Water and alcohols are mostly transparent and do not absorb in the UV-vis range and so are excellent mediums for UV-visible spectroscopy. Acetone and dimethylformamide (DMF) are good solvents for compounds insoluble in water and alcohol, but they absorb light below 320 and 275 nm, respectively, so are appropriate only above these cut-off wavelengths.
X-Ray Crystallography and Derivation of Braggs's lawShihabPatel
This document provides an overview of x-ray diffraction, including how x-rays are produced, Bragg's law which describes x-ray diffraction, different x-ray diffraction methods like rotating crystal technique and powder diffraction, types of crystals, and applications of x-ray diffraction like material identification and particle size determination. It contains sections on the production of x-rays, Bragg's law, rotating crystal technique, x-ray powder diffraction, types of crystals, and applications of x-ray diffraction.
Introduction,Instrumentation, Classification of electronic transitions, Substituent and solvent effects, Classification of electronic transitions
Substituent and solvent effects
Applications of UV Spectroscopy
UV spectral study of alkenes
UV spectral study of poylenes
UV spectral study of α, β-unsaturated carbonyl
UV spectral study of Aromatic compounds
Empirical rules for calculating λmax.
Applications of UV Spectroscopy, Empirical rules for calculating λmax.
Spectrofluorimetry uses fluorescence to analyze samples. Fluorescence occurs when molecules absorb ultraviolet or visible light then emit light at a higher wavelength. A spectrofluorimeter contains a light source, monochromators to isolate wavelengths, and a detector. It can quantify substances like vitamins, drugs, proteins, and more down to attogram levels. Though specific, fluorescence can be impacted by environmental factors and some compounds may not fluoresce. Areas of application include chemistry, biochemistry, medicine, and more.
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.
This document provides an overview of proton NMR spectroscopy. It begins with definitions of light and the electromagnetic spectrum. It then discusses spectroscopy in general and introduces NMR, focusing on proton NMR. The key concepts of proton NMR covered include its principle, instrumentation, chemical shifts, spin-spin splitting, deuterium exchange, and the n+1 rule. Applications discussed include distinguishing isomers, determining molecular weight, and studying tautomeric mixtures. Clinical, agricultural, and biological applications are also mentioned.
Ultraviolet–visible spectroscopy or ultraviolet-visible spectrophotometry (UV-Vis or UV/Vis) refers to absorption spectroscopy or reflectance spectroscopy in the ultraviolet-visible spectral region. This means it uses light in the visible and adjacent ranges.
Ion exchange chromatography uses ion exchange resins to separate mixtures of similarly charged ions through reversible ion exchange. There are four main types of resins classified by their chemical nature: strong cation, weak cation, strong anion, and weak anion exchange resins. Ion exchange resins must be chemically stable, insoluble in solvents, sufficiently cross-linked, and denser than water while containing ion exchange groups. Factors like the nature and properties of resins, exchanging ions, solution concentration, and charge impact ion exchange separations. Ion exchange chromatography has applications like water softening, demineralization, purification of solutions, separation of inorganic/organic ions, and use in HPLC columns.
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
UV/visible spectroscopy involves using electromagnetic radiation in the UV and visible light range to analyze samples. Key principles are that different functional groups and molecular structures absorb radiation at characteristic wavelengths. Absorption of light causes electronic transitions between molecular orbitals. The Beer-Lambert law states that absorbance is directly proportional to concentration, with molar absorptivity coefficients describing this relationship. Absorption spectra provide information to identify compounds and determine concentrations.
uv spectroscopy by HARVINDAR SINGH .M.PHARM PHARMACEUTICSHarevindarsingh
Ultraviolet-visible spectroscopy involves using UV or visible light to analyze samples. It works by measuring the absorption spectrum of a sample after passing light through it. The spectrum produced can be used to determine characteristics about the sample like its structure or concentration. Common applications of UV-Vis spectroscopy include identifying functional groups, determining the extent of conjugation, and elucidating unknown molecular structures.
spectrofluorometer is the instrument for recording fluorescence emission and absorption spectra When a beam of light is incident on certain substances they emit visible light or radiations. This is known as fluorescence. Fluorescence starts immediately after the absorption of light and stops as soon as the incident light is cut off. The substances showing this phenomenon are known as flourescent substances.
The coupling constant is the distance between peaks in a multiplet in NMR spectroscopy. It is measured in Hertz and does not depend on external magnetic field strength. The value of the coupling constant provides information to distinguish multiplets and can indicate structural features like cis/trans isomers. Coupling occurs between protons close in space, known as geminal, vicinal, and sometimes long-range coupling over several bonds. The coupling constant is affected by factors like bond angle, dihedral angle, and electronegativity of substituents.
X- ray crystallography, Shriyansh Srivastava, M.Pharm (Department of Pharmaco...Shriyansh Srivastav
X-ray crystallography uses X-rays to determine the atomic and molecular structure of crystals. Wilhelm Röntgen discovered X-rays in 1895. X-rays are produced when high velocity electrons collide with a metal target. X-ray crystallography works by firing a beam of X-rays at crystalline solids and observing the diffraction pattern of scattered X-rays. Bragg's law describes the conditions under which constructive interference of X-rays occurs and can be used to determine crystal structures. Common methods include rotating crystal, powder diffraction, and using detectors like photographic film, Geiger-Müller counters, or scintillation counters. X-ray crystallography has applications in determining protein structures and identifying
SPECTROSCOPY
INFRARED SPECTROSCOPY
HISTORY
PRINCIPLE
MODES OF VIBRATION
INSTRUMENTATION
SAMPLE HANDLING
FTIR (FOURIER TRANSFORM INFRARED) SPECTROMETER
PRINCIPLE
INSTRUMENTATION
WORKING
DISPERSIVE VERSUS FTIR
ADVANTAGES & DISADVANTAGES OF FTIR WITH APPLICATIONS
FACTORS AFFECTING VIBRATIONAL FREQUENCIES
IR SPECTRA REGION
IR SPECTRA INTERPRETATION
EXAMPLES
ADVANTAGES AND DISADVANTAGES OF IR
APPLICATIONS OF IR
Reference
The document provides an overview of mass spectrometry. It discusses the history, principles, instrumentation, ionization techniques, mass analyzers, and applications of mass spectrometry. Mass spectrometry involves converting sample molecules to ions, separating the ions based on their mass-to-charge ratio, and detecting the ions. Key components include an ion source, mass analyzer, and ion detector. Common ionization methods include electron ionization and chemical ionization. Common mass analyzers are magnetic sector, quadrupole, time-of-flight, and ion trap. Mass spectrometry has various applications in fields like proteomics, metabolomics, and environmental analysis.
Nuclear magnetic resonance (NMR) spectroscopyVK VIKRAM VARMA
SPECTROSCOPY
NMR SPECTROSCOPY
HISTORY
THEORY
PRINCIPLE
INSTRUMENTATION
SOLVENTS USED IN NMR(PROTON NMR)
CHEMICAL SHIFT
FACTORS AFFECTING CHEMICAL SHIFT
RELAXATION PROCESS
SPIN-SPIN COUPLING
푛+1 RULE
NMR SIGNALS IN VARIOUS COMPOUNDS
COUPLING CONSTANT
NUCLEAR MAGNETIC DOUBLE RESONANCE/ SPIN DECOUPLING
FT-NMR
ADVANTAGES & DISADVANTAGES
APPLICATIONS
REFERENCE
An opto-electric nuclear battery is a device that converts nuclear energy into light, which it then uses to generate electrical energy. A beta-emitter such as technetium-99 or strontium-90 is suspended in a gas or liquid containing luminescent gas molecules of the excimer type, constituting a "dust plasma." This permits a nearly lossless emission of beta electrons from the emitting dust particles
This document provides information about a course on high voltage engineering taught at Dr. N.G.P. Institute of Technology. The course objectives are to teach students about various types of over voltages in power systems, methods for generating high voltages in laboratories, measuring high voltages, breakdown mechanisms in dielectrics, and testing of power apparatus. The course outcomes are that students will be able to explain causes of over voltages, describe breakdown mechanisms, illustrate high voltage generation methods, use methods to measure high voltages and currents, and explain high voltage testing and insulation coordination. The syllabus covers topics like over voltages, dielectric breakdown, high voltage generation, measurement, and testing.
This document discusses different types of energy sources, including renewable and non-renewable sources. It focuses on geothermal energy sources and how they work. Geothermal energy harnesses heat from the earth and uses it to power turbines that generate electricity. There are different types of geothermal power plants including dry steam, flash steam, and binary cycle plants that use various methods to convert heat from underground reservoirs into electricity without burning fuels. The document also briefly discusses fusion power and the potential it has to provide an unlimited clean energy source.
This document provides an overview of wireless power transmission (WPT), including its history, types, advantages, and applications. It discusses how Nikola Tesla first proposed WPT in the late 1890s using atmospheric conduction methods. Two main electrodynamic induction methods are microwave and laser transmission. WPT could be used for electric vehicle charging, consumer electronics, and transmitting power from solar satellites. While more efficient than wired systems, WPT also faces challenges like interference, conversion inefficiencies, and safety concerns around high frequencies.
Magneto hydro dynamic power generation (mhd power generation)Rishabhlko
This document presents information on magneto hydro dynamic (MHD) power generation. MHD power generation uses electrically conducting fluids, like plasmas, liquid metals, and salt water that are passed at high velocity through a powerful magnetic field to generate an electric current. The document discusses the principles and working of both open-cycle and closed-cycle MHD systems. Open-cycle systems use combustion of fuels to heat gases that are then seeded and passed through an MHD generator. Closed-cycle systems circulate liquid metals or inert gases through a Brayton power cycle. MHD power generation has advantages of high efficiency and compact size but challenges include requirements for very high fluid velocities and temperatures.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
An arc flash incident occurred at a coal mine when a 3.3kV back to back coupler failed under load. The investigation found a high resistance joint caused a phase to phase fault. While electrical protections operated, the closest protection relay did not operate fast enough to minimize incident energy. Modeling found actual clearing times were longer than settings. Protection settings were optimized to halve the incident energy by clearing faults up to 4 cycles faster through reduced time delays. Future considerations include challenging protection designs and settings to be as low risk as reasonably practicable.
The document discusses non-conventional machining processes. It begins with an introduction explaining the limitations of traditional machining methods and the need for alternative processes. It then classifies non-conventional machining into four main categories: mechanical, thermal, chemical, and electrochemical machining. Specific examples of processes are described within each category, such as ultrasonic machining, electric discharge machining, and electrochemical machining. The document provides details on the mechanisms and applications of several important non-conventional machining methods.
This document discusses blasting in mining operations. It begins by explaining that blasting is used to break rock into smaller pieces for mining and quarrying, or to create space. The objectives of blasting are to extract material at minimum cost while meeting production quality and quantity requirements. It then covers the different types of explosions, explosives, detonation and deflagration processes, properties and types of explosives, initiating systems including electrical, non-electric, detonating cord, and blast design considerations like burden, spacing, stemming, and bench height.
This document discusses using ultracapacitors to store solar energy collected by satellites and transmit power via microwaves. Ultracapacitors store energy electrostatically instead of chemically like batteries, and have advantages of long lifetime, temperature resistance, and high efficiency. Solar panels on satellites collect energy which is stored in ultracapacitors. A voltage regulator maintains a constant voltage, which a microwave converter transforms to microwaves. These microwaves are transmitted to and received by the power receiving end of receiving satellites or vessels. The document concludes ultracapacitors are well-suited for maximum solar power production and transmission from satellites.
This document discusses Magneto Hydro Dynamic (MHD) power generation. It begins with introducing MHD and its principles, which involve inducing electric current when a conducting fluid passes through a magnetic field. It then describes various MHD systems including open cycle systems using seeded inert gases, closed cycle systems, and liquid metal systems. The document provides details on the components and working of each system. It highlights that MHD power generation is more efficient and less polluting than traditional thermal plants.
This document discusses nuclear waste management. It provides definitions of radioactivity and the different types of radiation. It classifies radioactive waste and discusses sources and the half-life of nuclear waste. Mathematical models for modeling radioactive waste leaching are presented. The effects of nuclear waste on health and the environment are addressed. Options for nuclear waste disposal like geological dumping, ocean dumping, and transmutation are covered. The status of radioactive waste management in India is also summarized.
This document discusses key parameters of solar cells such as open circuit voltage (Voc), short circuit current (Isc), fill factor (FF), and efficiency. It describes how these parameters are affected by factors like series resistance (Rs), shunt resistance (Rsh), and quantum efficiency. Voc is the maximum voltage produced at zero current, while Isc is the maximum current at zero voltage. FF accounts for non-idealities and is used to calculate the maximum power point. Rs and Rsh are parasitic resistances that lower FF. Quantum efficiency measures the number of carriers collected per photon over absorption and reflects losses from reflection and recombination.
ELECTRICAL ENERGY GENERATION, TRANSMISSION, AND GENERATION.pptxLuzvimindaVercelesDu
Electricity is generated through various methods such as thermal, nuclear, and renewable sources. It is transmitted through high voltage power lines and distributed through lower voltage lines to reach consumers. The distribution process involves stepping down voltage levels at transmission substations and distribution transformers located between generating plants and end users.
This document proposes installing capacitor banks on the 11kV Toitskraal feeder to improve the poor power factor. The feeder has a peak power factor of 0.78 lagging due to inductive loads like irrigation pumps. One 500kVAr fixed capacitor bank and one 750kVAr switched bank will be installed. Simulations show the banks will reduce line loading, losses, and improve voltages while paying for themselves within 4.65 months through energy savings. The project is recommended to optimize the network and significantly reduce costs.
Supercapacitors are electrochemical capacitors that can store and deliver energy at high rates. They have a higher energy density than traditional capacitors. A supercapacitor was first developed in 1947 using porous carbon electrodes, though the double-layer storage mechanism was unknown at the time. Supercapacitors have advantages over batteries like high charge/discharge rates, little degradation over hundreds of thousands of cycles, and high cycle efficiency. However, their energy density is lower than batteries and voltage varies with stored energy. Applications include transportation, backup power systems, and consumer electronics.
Similar to UV(Ultraviolet) visible spectroscopy (Analytical Technique) (20)
MICROBIAL CONTAMINATION IN HERBS AND THEIR FORMULATIONSVK VIKRAM VARMA
INTRODUCTION
SOURCES OF CONTAMINATION
RAW MATERIALS
PACKAGING MATERIALS
LIMITS FOR MICROBIAL CONTAMINATION
LIMITS AS PER WHO
TYPES OF CONTAMINATION
DIRECT CONTAMINATION
CROSS CONTAMINATION
DETERMINATION OF CONTAMINATION
TOTAL VIABLE COUNT
PRETREATMENT OF HERBAL MATERIALS
REFRENCES
Micropropagation
steps of micropropagation
system used to regenerate plantlets by micropropagation
methods of micropropagation
embrogensis
organogenesis
bud culture
How does micropropogation work?
Examples with flow diagrams
Advantages & Disadvantages
Applications
Reference
CCRAS (central council for reasearch in ayurvedic sciences)VK VIKRAM VARMA
Introduction
Sowa-Rigpa
CCRAS Website
CCRAS Vision & Mission
Organisation chart
Seniority List
Institutes
Research Activities
The Broad Areas of Research Comprise
Clinical Research
Fundamental Research
Pharmacology Research
Medicinal Plant Research, Drug Standardisation Research
Literature Research
AYUSH Research Portal
Outreach Activities
Publications
E-books
Reference
Introduction
Classification with examples
Regulatory provisions relating to manufacturing the cosmetics
Requirements of the factory premises for manufacture of cosmetics
Requirements of plant and equipment
Manufacturing record
Prohibition of the manufacture
Offences and penalties
Export and import of potential herbal cosmetics
Some Indian importers of herbal cosmetics
WHAT IS PHARMACOPOEIA?
HISTORY OF PHARMACOPOEIA
CONTENT OF PHARMACOPOEIA
WHAT IS MONOGRAPH?
PURPOSE OF MONOGRAPH
TYPES OF MONOGRAPH
IMPORTANCE OF CONTENT OF MONOGRAPH
MONOGRAPH DEVELOPMENT PROCESS
INDIAN PHARMACOPOEIA
format of monograph
AYURVEDIC PHARMACOPOEIA
format of monograph
UNNANI PHARMACOPOEIA
format of monograph
SIDDHA PHARMACOPOEIA
format of monograph
GERMAN HOMOEPATHIC PHARMACOPOEIA
format of monograph
US PHARMACOPOEIA
format of monograph
JAPANESE PHARMACOPOEIA
format of monograph
BRITISH PHARMACOPOEIA
format of monograph
EUROPEAN PHARMACOPOEIA
format of monograph
COMPARATIVE STUDY
CONCLUSION
Reference
This document provides information about the Department of Science and Technology in India. It discusses the following key points:
- The DST was established in 1971 and aims to coordinate and promote science and technology activities in India by funding projects and supporting researchers.
- It oversees various scientific programs related to socioeconomic development, international cooperation, research and engineering. This includes organizations like SERB, INSPIRE and the National Science and Technology Entrepreneurship Development Board.
- The DST also runs programs focused on women scientists and open data sharing policies to maximize the benefits of research funded by public money.
This document discusses dietary fibers, cereals, and grains. It defines dietary fiber as a complex carbohydrate that is not digested in the small intestine. It then classifies fibers into insoluble and soluble, describing the main types of each. Insoluble fibers like cellulose add bulk and speed food movement through the digestive tract, while soluble fibers like pectin and gums form gels to slow digestion. Resistant starches are also discussed. The document lists several foods and their fiber contents, and describes the roles of fiber in health, such as reducing cholesterol and blood sugar levels. It concludes with safe fiber intake recommendations and some potential issues with excess fiber consumption.
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
How to Fix the Import Error in the Odoo 17Celine George
An import error occurs when a program fails to import a module or library, disrupting its execution. In languages like Python, this issue arises when the specified module cannot be found or accessed, hindering the program's functionality. Resolving import errors is crucial for maintaining smooth software operation and uninterrupted development processes.
This presentation was provided by Steph Pollock of The American Psychological Association’s Journals Program, and Damita Snow, of The American Society of Civil Engineers (ASCE), for the initial session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session One: 'Setting Expectations: a DEIA Primer,' was held June 6, 2024.
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
Main Java[All of the Base Concepts}.docxadhitya5119
This is part 1 of my Java Learning Journey. This Contains Custom methods, classes, constructors, packages, multithreading , try- catch block, finally block and more.
Reimagining Your Library Space: How to Increase the Vibes in Your Library No ...Diana Rendina
Librarians are leading the way in creating future-ready citizens – now we need to update our spaces to match. In this session, attendees will get inspiration for transforming their library spaces. You’ll learn how to survey students and patrons, create a focus group, and use design thinking to brainstorm ideas for your space. We’ll discuss budget friendly ways to change your space as well as how to find funding. No matter where you’re at, you’ll find ideas for reimagining your space in this session.
How to Add Chatter in the odoo 17 ERP ModuleCeline George
In Odoo, the chatter is like a chat tool that helps you work together on records. You can leave notes and track things, making it easier to talk with your team and partners. Inside chatter, all communication history, activity, and changes will be displayed.
Leveraging Generative AI to Drive Nonprofit InnovationTechSoup
In this webinar, participants learned how to utilize Generative AI to streamline operations and elevate member engagement. Amazon Web Service experts provided a customer specific use cases and dived into low/no-code tools that are quick and easy to deploy through Amazon Web Service (AWS.)
How to Setup Warehouse & Location in Odoo 17 InventoryCeline George
In this slide, we'll explore how to set up warehouses and locations in Odoo 17 Inventory. This will help us manage our stock effectively, track inventory levels, and streamline warehouse operations.
4. CONTD.
•SPECTROMETRY IS THE APPLICATION OF
SPECTROSCOPY SO THAT THERE ARE QUANTIFIABLE
RESULTS THAT CAN THAN BE ASSESSED.
•SPECTROPHOTOMETER OR SPECTROMETER: THE
INSTRUMENT THAT IS USED TO MEASURE THE
AMOUNT OF ELECTRO MAGNETIC RADIATION
ABSORBED BY AN ORGANIC MOLECULE.
24-12-2019V.K. VIKRAM VARMA 4
5. UV-VISIBLE SPECTROCOPY
•IT INVOLVES THE STUDY OF INTERACTION OF UV-VISIBLE
RADIATION WITH MOLECULES & THE ELECTRONIC
SPECTRA OF COMPOUNDS ARE ASSCIATED WITH
MEASUREMENTS OF ENERGY ABSORBED WHEN
ELECTRON IS PROMOTED TO HIGHER ENERGY LEVELS
(LOW ENERGY TO HIGH ENERGY), IN RANGE OF 200-800𝑛𝑚
(UV=200-400 𝑛𝑚 & VISIBLE=400-800 𝑛𝑚).
24-12-2019V.K. VIKRAM VARMA 5
7. PRINCIPLE
•ANY MOLECULES HAS EITHER 𝑛, 𝜋 𝑜𝑟 𝜎 𝑜𝑟 A CMBINATION OF THESE
ELECTRONS. THESE BONDING(𝜎&𝜋) & NON BONDING (𝑛) ELECTRONS
ABSORB THE CHARACTERISTIC RADIATION & UNDERGOES
TRANSITION FROM GROUND STATE TO EXCITED STATE.
•BY THE CHARACTERISTIC ABSORPTION PEAKS, THE NATURE OF
THE ELECTRONS PRESENT & HENCE THE MOLECULAR STRUCTURE
CAN BE ELUCIDATED.
24-12-2019V.K. VIKRAM VARMA 7
8. THEORY
•WHEN THE MOLECULE ABSORBS ULTRAVIOLET OR
VISIBLE LIGHT, ITS ELECTRONS GET PROMOTED FROM
THE GROUND STATE TO THE HIGHER ENERGY STATE.
•IN THE GROUND STATE, THE SPINS OF THE ELECTRONS IN
EACH MOLECULAR ORBITAL ARE ESSENTIALLY PAIRED.
•IN THE HIGHER ENERGY STATE, IF THE SPINS OF THE
ELECTRONS ARE PAIRED, THEN IT IS CALLED AN EXCITED
SINGLET STATE.
24-12-2019V.K. VIKRAM VARMA 8
9. CONTD.
•UV-VISIBLE RADIATION INTERACTS WITH MATTER WHICH CAUSES
ELECTRONIC TRANSITIONS.
•HOW EXCITATION OF ELECTRONS OCCURS:
MOLECULE → ABSORBS LIGHT → ELECTRONS ARE PROMOTED
FROM GROUND TO HIGHER STATE.
IN GROUND STATE → SPINS OF ELECTRONS ARE PAIRED → UV
RADIATION → ELECTRON CHARGE CLOUD IS DISTRIBUTED →
DISTORTION OF CHARGE CLOUD PRODUCES DIPOLE.
24-12-2019V.K. VIKRAM VARMA 9
10. CONTD.
•HIGHER ENERGY ORBITALS ARE ANTIBONDING MOLECULAR
ORBITALS.
•TRANSITION OF ELECTRON OCCURS FROM HOMO(HIGHEST
OCCUPIED MOLECULAR ORBITAL) TO LUMO(LOWEST UNOCCUPIED
MOLECULAR ORBITAL).
•POSSIBLE ELECTRONIC TRANSITION:
𝝈 𝒕𝒐 𝝈∗ TRANSITION
𝒏 𝒕𝒐 𝝈∗ TRANSITION
𝝅 𝒕𝒐 𝝅∗ TRANSITION
𝒏 𝒕𝒐 𝝅∗ TRANSITION
24-12-2019V.K. VIKRAM VARMA 10
12. 𝝈 𝒕𝒐 𝝈∗
TRANSITION
•ENERGY REQUIRED 150𝑛𝑚.
•VACCUM UV REGION(BELOW 200𝑛𝑚) – PATH LENGTH
SHOULD BE FREE FROM AIR.
•SATURATED HYDROCARBONS (METHANE, PROPANE).
24-12-2019V.K. VIKRAM VARMA 12
13. •ENERGY REQUIRED 175𝑛𝑚(APPROX.).
•WHEN HETEROATOM IS PRESENT IN SATURATED
COMPOUND. E.G.: ALCOHOLS, ALDEHYDES, KETONE,
AMINE, WATER ETC.
24-12-2019V.K. VIKRAM VARMA 13
𝒏 𝒕𝒐 𝝈∗
TRANSITION
14. •ENERGY REQUIRED MORE THAN 200𝑛𝑚 (DEPENDS
ON CONJUGATION) LESS THAN 𝑛 𝑡𝑜 𝜎∗.
•WHEN ANY DOUBLE, TRIPLE BONDED
HYDROCARBONS, AROMATIC COMPOUNDS ARE
PRESENT.
24-12-2019V.K. VIKRAM VARMA 14
𝝅 𝒕𝒐 𝝅∗
TRANSITION
15. •MORE THAN 200𝑛𝑚 (DEPENDS ON CONJUGATION OF
COMPOUNDS).
•WHEN CARBONYL COMPOUNDS ARE PRESENT.
24-12-2019V.K. VIKRAM VARMA 15
𝒏 𝒕𝒐 𝝅∗
TRANSITION
ENERGY REQUIRED FOR VARIOUS TRANSITIONS
OBEY THE FOLLOWING ORDER:
𝝈 → 𝝈∗
> 𝒏 → 𝝈∗
> 𝝅 → 𝝅∗
> 𝒏 → 𝝅∗
16. LAWS
•WHEN A BEAM OF LIGHT FALLS ON A SOLUTION OR HOMOGENEOUS
MEDIA, A PORTION OF LIGHT IS ABSORBED WITHIN THE MEDIUM
WHILE THE REMAINING IS TRANSMITTED THROUGH THE MEDIUM.
•THUS IF 𝐼0 IS THE INTENSITY OF RADIATION FALLING ON THE
MEDIA, 𝐼 𝑎 IS THE AMOUNT OF RADIATION ABSORBED & 𝐼𝑡 AS THE
AMOUNT OF RADIATION TRANSMITTED THEN,
𝑰 𝟎 = 𝑰 𝒂 + 𝑰 𝒕
24-12-2019V.K. VIKRAM VARMA 16
17. CONTD.
• WHERE,
𝑰= INTENSITY OF INCIDENT LIGHT
𝒄=MOLAR CONCENTRATION OF SAMPLE
𝒃 =LENGTH OR THICKNESS OF THE
SAMPLE CELL
𝑰 𝒂= INTENSITY OF ABSORBED LIGHT
𝑰 𝒕 =INTENSITY OF TRANSMITTED LIGHT
24-12-2019V.K. VIKRAM VARMA 17
18. LAMBERT’S LAW
• WHEN A BEAM OF MONOCHROMATIC LIGHT IS PASSED THROUGH ABSORBING
MEDIUM, THEN THE DECREASE IN INTENSITY OF RADIATION WILL BE DIRECTLY
PROPORTIONAL TO THE THICKNESS(PATH LENGTH) OF THE SOLUTION.
𝑨 = 𝐥𝐨𝐠 𝟏𝟎
𝑰 𝑶
𝑰
𝜶 𝒍
𝑨𝜶 𝒍
𝑨 = 𝜺𝒍
24-12-2019V.K. VIKRAM VARMA 18
Where,
𝜀- molar absorptivity
𝑙- path length
(units 𝐿
𝑚𝑜𝑙−𝑐𝑚 )
19. BEER’S LAW
24-12-2019V.K. VIKRAM VARMA 19
•WHEN A BEAM OF MONOCHROMATIC LIGHT IS PASSED THROUGH
ABSORBING MEDIUM, THEN THE DECREASE IN INTENSITY OF
RADIATION WILL BE DIRECTLY PROPORTIONAL TO THE
CONCENTRATION OF THE SOLUTION.
𝑨 = 𝐥𝐨𝐠 𝟏𝟎
𝑰 𝑶
𝑰
𝜶 𝒄
𝑨𝜶 𝒄
𝑨 = 𝜺𝒄
Where,
𝜀- molar absorptivity
𝑐-concentration of the solution
20. LAMBERT-BEER LAW
24-12-2019V.K. VIKRAM VARMA 20
•WHEN A BEAM OF MONOCHROMATIC LIGHT IS PASSED THROUGH
ABSORBING MEDIUM, THEN THE DECREASE IN INTENSITY OF
RADIATION WILL BE DIRECTLY PROPORTIONAL TO THE
THICKNESS(PATH LENGTH) AS WELL AS CONCENTRATION OF THE
SOLUTION.
𝑨 = 𝐥𝐨𝐠 𝟏𝟎
𝑰 𝑶
𝑰
𝜶 𝒍 × 𝒄
𝑨 𝜶 𝒍 × 𝒄
𝑨 = 𝜺 × 𝒍 × 𝒄
Where,
𝜀- molar absorptivity
𝑐-concentration of the solution
𝑙- path length
21. TERMS USED IN UV-VISIBLE
SPECTROSCOPY
•CHROMOPHORES
CHROMOPHORES ARE COVALENTLY BONDED MOIETIES
WITH ANY COMPOUND & RESPONSIBLE FOR ABSORPTION OF
UV-VISIBLE RADIATIONS. E.G. ALDEHYDE, ETHYLENE,
CARBONYL ETC.
TYPES
a.CHROMOPHORE WITH 𝝅 − 𝝅∗. E.G.𝑪 = 𝑪, 𝑪 ≡ 𝑪.
b.CHROMOPHORE WITH 𝒏 − 𝝅∗. E.G.𝑪𝑶𝑶𝑯, 𝑵 = 𝑵.
24-12-2019V.K. VIKRAM VARMA 21
22. CONTD.
• AUXOCHROMES
THESE ARE COORDINATELY SATURATED OR UN-SATURATED GROUPS
WHICH THEMSELVES DO NOT ABSORB RADIATIONS, BUT WHEN
PRESENT ALONG WITH A CHROMOPHORE ENHANCES THE ABSORBING
PROPERTIES OF CHROMOPHORE.
ALSO KNOWN AS COLOR ENHANCING GROUP.
EFFECT OF AUXOCHROME IS DUE TO ITS ABILITY TO EXTEND THE
CONJUGATION OF A CHROMOPHORE BY SHARING OF ITS NON-
BONDING ELECTRONS.
E.G. −𝑶𝑯, −𝑵𝑯 𝟐, −𝑶𝑹, −𝑺𝑯 ETC.
24-12-2019V.K. VIKRAM VARMA 22
24. •SHIFT TOWARD LONGER
WAVELENGTH.
•REASONS FOR RED SHIFT:
ADDITION OF CHROMOPHORES
OR AUXOCHROMES.
SOLVENT EFFECT
INCREASING CONJUGATION.
•EXAMPLE: IN ALAKLINE MEDIUM,
𝑝 − 𝑛𝑖𝑡𝑟𝑜𝑝ℎ𝑒𝑛𝑜𝑙 SHOWS RED SHIFT.
24-12-2019V.K. VIKRAM VARMA 24
BATHOCHROMIC SHIFT(RED
SHIFT)
25. HYPSOCHROMIC SHIFT (BLUE
SHIFT)
• SHIFT TOWARDS SHORTER WAVE
LENGTH.
• REASONS FOR BLUE SHIFT:
REMOVAL OF CHROMOPHORE
OR AUXOCHROME.
SOLVENT EFFECT.
REMOVAL OF CONJUGATION.
• ANILINE SHOWS BLUE SHIFT IN
ACIDIC MEDIUM, IT LOSES
CONJUGATION.
24-12-2019V.K. VIKRAM VARMA 25
26. HYPERCHROMIC SHIFT
•SHIFTING OF ABSORPTION
INTENSITY (𝜀) TOWARDS
HIGHER VALUES.
•IF AUXOCHROMES
INTRODUCED TO THE
COMPOUND, THE INTENSITY
OF ABSORPTION INCREASES.
24-12-2019V.K. VIKRAM VARMA 26
28. WOODWARD-FEISER RULE
•WOODWARD (1941): GAVE CERTAIN RULES FOR CORRELATING 𝜆 𝑚𝑎𝑥
WITH MOLECULAR STRUCTURE.
•SCOTT-FEISER (1959): MODIFIED THE RULE WITH MORE
EXPERIMENTAL DATA, THE MODIFIED RULE IS KNOWN AS
WOODWARD-FEISER RULE,
USED TO CALCULATE THE POSITION OF 𝝀 𝒎𝒂𝒙 FOR A GIVEN
STRUCTURE BY RELATING THE POSITION & DEGREE OF
SUBSTITUTION OF CHROMOPHORE.
24-12-2019V.K. VIKRAM VARMA 28
29. CONTD.
•HOMOANNULAR DIENE: CYCLIC
DIENE HAVING CONJUGATED
DOUBLE BONDS IN THE SAME RING.
•HETEROANNULAR DIENE: CYCLIC
DIENE HAVING CONJUGATED
DOUBLE BONDS IN DIFFERENT RING.
24-12-2019V.K. VIKRAM VARMA 29
30. CONTD.
•ENDOCYCLIC DOUBLE BOND: DOUBLE BOND
PRESENT IN RING
•EXOCYCLIC DOUBLE BOND: DOUBLE BOND
IN WHICH ONE OF THE DOUBLY BONDED
ATOMS IS A PART OF A RING SYSTEM.
RING A HAS ONE EXOCYCLIC &
ENDOCYCLIC DOUBLE BOND.
RING B HAS ONLY ONE ENDOCYCLIC
DOUBLE BOND
24-12-2019V.K. VIKRAM VARMA 30
31. WOODWARD-FEISER RULE FOR CONJUGATED
DIENES, TRIENES, POLYENES
•EACH TYPE OF DIENEOR TRIENE SYSTEM IS HAVING A
CERAIN FIXED AT WHICH ABSORPTION TAKES PLACE;THIS
CONSTITUENTS THE BASIC VALUE OR PARENT VALUE.
•THE CONTRIBUTION MADE BY VARIIOUS ALKYL
SUBSTITUENTS OF RING RESIDUE, DOUBLEBONDS
EXTENDING CONJUGATION & POLAR GROUPS SUCH AS
− 𝐶𝑙, −𝐵𝑟 ARE ADDED TO THE BASIC VALUE TO OBTAIN 𝜆 𝑚𝑎𝑥
FOR PARTICULAR COMPOUND.
24-12-2019V.K. VIKRAM VARMA 31
32. PARENT VALUES & INCREMENTS FOR DIFFERENT
GROUPS
24-12-2019V.K. VIKRAM VARMA 32
41. LIGHT/ RADIATING SOURCE
REQUIREMENTS:
•IT SHOLD BE STABLE.
•IT SHOULD PROVIDE CONTINUOUS RADIATION.
•IT MUST BE OF THE SUFFICIENT INTENSTIY FOR THE
TRANSMITTED ENERGY TO BE DETECTED AT THE END OF
THE OPTICAL PATH.
24-12-2019V.K. VIKRAM VARMA 41
43. † HYDROGEN & DEUTERIUM
LAMP
•A CONTINUUM SPECTRUM IN THE UV REGION IS PRODUCED BY
ELECTRICAL EXCITATION OF HYDROGEN OR DEUTERIUM.
•INTIALLY THE DEUTERIUM MOLECULE ABSORB ELECTRICAL
ENERGY. WHICH RESULTS I THE FORMATION OF AN EXCITED
SPECIES FOLLOWED BY THE DISSOCIATION OF EXCITED
MOLECULE IN TO TWO ATOMIC SPECIES PLUS A UV PHOTON
•THUS A CONTINUUM SPECTRUM IS OBTAINED FROM 160-375𝑛𝑚.
24-12-2019V.K. VIKRAM VARMA 43
44. CONTD.
•THE ENERGY OF PHOTON CAN VARY CONTINUOUSLY. ONLY
QUARTZ CUVETTES AR USED, BECAUSE GLASS ABSORB RADIATION
OF WAVE LENGTH LESS THAN 350𝑛𝑚.
•ADVANTAGES:
INTENSITY OF RADIATION IS EMITTED 3-5 TIMES THE
INTENSITY OF HYDROGEN LAMP.
RADIATION IS STABLE
•DISADVANTAGES:
EXPENSIVE
24-12-2019V.K. VIKRAM VARMA 44
46. † TUNGSTEN LAMP
•SIMILAR IN ITS FUNCTIONING TO AN ELECTRIC BULB
•IT PROVIDES A SUPPLY OF RADIATION I THE WVELENGTH
RANGE OF 320-2500𝑛𝑚.
•CONTINUOUS SOURCE OF LIGHT
•WHEN TUNGSTEN FILAMENT IS HEATED TO
INCANDESCENCE BY AN ELECTRIC CURRENT, THE LIGHT
IS PRODUCED.
24-12-2019V.K. VIKRAM VARMA 46
47. CONTD.
•THE GLASS BULB ENCLOSING THE FILAMENT CONTAINS
A LOW PRESSURE OF INERT GAS, USUALLY ARGON.
•SMALL AMOUNTS OF HALOGEN LIKE IODINE IS ADDED TO
IMPROVE THE INTENSITY (TUNGSTEN-IODINE LAMP).
•ADVANATGES:
HAVE LONG HALF LIFE
STABLE, CHEAP, EASY TO USE
24-12-2019V.K. VIKRAM VARMA 47
49. † XENON DISCHARGE LAMP
• XENON GAS IS STORED IN LAMPS AT 10-30 ATMOSPHERIC
PRESSURE.
•IT CONTAIN 2 TUNGSTEN ELECTRODES THAT ARE
SEPARATED BY A DISTANCE OF ABOUT 8𝑚𝑚.
•WHEN CURRENT PASSES THROUGH XENON CAUSE
THERMAL EXCITATION.
24-12-2019V.K. VIKRAM VARMA 49
50. CONTD.
•IT PRODUCES GREATER UV RADIATION THAN THE
HYDROGEN LAMP.
•CONTINUOUS SOURCE
•ADVANTAGES:
THE INTENSITY OF UV RADIATION PRODUCED ARE
GREATER THAN THAT OF HYDROGEN LAMP.
EMIT BOTH UV & VISIBLE WAVE LENGTH. XENON
DISCHARGE LAMP
24-12-2019V.K. VIKRAM VARMA 50
51. CONTD.
•DISADVANTAGES:
THE LAMP SINCE OPERATES AT HIGH VOLTAGE BECOMES VERY
HOT DURING OPERATION & HENCE NEEDS THERMAL
INSULATION.
24-12-2019V.K. VIKRAM VARMA 51
52. † MERCURY VAPOUR LAMP
•MERCURY VAPOUR IS STORED
UNDER HIGH PRESSURE &
EXCITATION OF MERCURY ATOMS
IS DONE BY ELECTRIC DISCHARGE.
•NOT SUITABLE FOR CONTINUOUS
SPECTRAL STUDIES, BECAUSE OF
THE PRESENCE OF SHARP LINES
OR BANDS.
24-12-2019V.K. VIKRAM VARMA 52
53. WAVE LENGTH SELECTORS
•MOST OF THE SPECTROSCOPIC ANALYSIS RADIATION THAT
CONSIST OF A LIMITED NARROW CONTINUOUS GROUP OF WAVE
LENGTH IS CALLED AS BAND.
•IDEALLY THE OUTPUT FROM A WAVELENGTH SELECTOR WOULD BE
A RADIATION OF SINGLE WAVELENGTH / FREQUENCY.
•A NARROW BAND WIDTH REPRESENTS BETTER PERFORMANCE.
•A FILTER OR MONOCHROMATORS IS USED WHICH CONVERTS
POLYCHROMATIC LIGHT TO MONOCHROMATIC LIGHT.
24-12-2019V.K. VIKRAM VARMA 53
54. † MONOCHROMATOR
•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
•POLYCHROMATIC RADIATION (RADIATION OF MORE THAN ONE
WAVE LENGTH) ENTERS THE MONOCHROMATOR THROUGH THE
ENTRANCE SLIT.
24-12-2019V.K. VIKRAM VARMA 54
55. CONTD.
•THE BEAM IS COLLIMATED, & THEN STRIKES THE
DISPERSING ELEMENT AT THE ANGLE.
•THE BEAM IS SPLIT IN TO IT COMPONENT WAVELENGTHS
BY THE GRATING OR PRISM.
•BY MOVING THE DISPERSING ELEMENT OR THE EXIT SLIT,
THE RADIATION OF ONLY A PARTICULAR WAVELENGTH
LEAVES THE MONOCHROMATOR THROUGH THE EXIT SLIT.
24-12-2019V.K. VIKRAM VARMA 55
56. CONTD.
•IN SPECTROPHOTOMETER 2
TYPES OF WAVELENGTH
SELECTORS ARE USED,
•MONOCHROMATORS
•FILTERS
•TYPES OF
MONOCHROMATORS
•PRISM TYPE
•DISPERSIVE TYPE
•LITTROW TYPE
•GRATING TYPE
•DIFFRACTION
GRATING
•TRANSMISSION
GRATING
24-12-2019V.K. VIKRAM VARMA 56
57. ۞ PRISMS
•THE PRISMS DISPERSE THE LIGHT RADIATION
INTO INDIVIDUAL COLORS OR WAVELENGTHS.
•THESE ARE FOUND IN INEXPENSIVE
INSTRUMENTS.
•THE BAND PASS IS LOWER THAN THAT OF
FILTERS & HENCE IT HAS BETTER
RESOLUTION.
•THE RESOLUTION DEPENDS UPON THE SIZE &
REFRACTIVE INDEX OF THE PRISM.
•THE MATERIAL OF PRISM IS NORMALLY GLASS
24-12-2019V.K. VIKRAM VARMA 57
58. CONTD.
REFRACTIVE TYPE (DISPERSIVE TYPE)
•THE SOURCE OF LIGHT THROUGH ENTRANCE SLIT FALLS
ON A COLLIMATOR.
•THE PARALLEL RADIATION FROM COLLIMATOR ARE
DISPERSED INTO DIFFERENT COLORS OR WAVELENGTHS
& BY USING ANOTHER COLLIMATOR, THE IMAGES OF
ENTRANCE SLIT ARE REFORMED.
24-12-2019V.K. VIKRAM VARMA 58
59. CONTD.
•THE REFORMED ONES WILL BE EITHER VIOLET,
INDIGO, BLUE, GREEN, YELLOW, ORANGE OR RED.
•THE REQUIRED RADIATION ON EXIT SLIT ARE BE
SELECTED BY ROTATING THE PRISM OR BY
KEEPING THE PRISM STATIONARY & MOVING THE
EXIT SLIT.
24-12-2019V.K. VIKRAM VARMA 59
61. CONTD.
REFLECTIVE TYPE ( LITTROW TYPE):
•THE PRINCIPLE OF WORKING IS SIMILAR TO THE
REFRACTIVE TYPE EXCEPT THAT, A REFLECTIVE
SURFACE IS PRESENT ON ONE SIDE OF THE PRISM.
•HENCE THE DISPERSED RADIATIONS GETS REFLECTED &
CAN BE COLLECTED ON THE SOURCE OF LIGHT.
24-12-2019V.K. VIKRAM VARMA 61
63. GRATINGS
•GRATING ARE THE MOST EFFICIENT ONES IN
CONVERTING A POLYCHROMATIC TO MONOCHROMATIC
LIGHT.
•AS A RESOLUTION OF ± 0.1𝑛𝑚 COULD BE ACHIEVED BY
USING GRATINGS, THEY ARE COMMONLY USED IN
SPECTROPHOTOMETER.
•GRATING ARE OF TWO TYPES:
•DIFFRACTION GRATING
•TRANSMISSION GRATING
24-12-2019V.K. VIKRAM VARMA 63
64. CONTD.
DIFFRACTION GRATING
•MORE REFINED DISPERSION OF LIGHT IS OBTAINED BY MEANS OF
DIFFRACTION GRATINGS.
•THESE ARE THE RULINGS MASE ON SAMPLE MATERIAL LIKE GLASS,
QUARTS, OR ALKYL HALIDES, DEPENDING UPON THE INSTRUMENT.
•THESE CONSISTS OF LARGE NUMBER OF PARALLEL LINES
(GROOVES) ABOUT 15000-30000/INCH IS RULED ON HIGHLY
POLISHED SURFACE OF ALUMINUM.
24-12-2019V.K. VIKRAM VARMA 64
66. CONTD.
•TO MAKE THE SURFACE REFLECTIVE, A DEPOSIT OF
ALUMINUM IS MADE ON THE SURFACE. IN ORDER TO
MINIMIZE TO GREATER AMOUNTS OF SCATTERED
RADIATION & APPEARANCE OF UNWANTED RADIATION
OF OTHER SPECTRAL ORDERS, THE GRATINGS ARE
BLAZED TO CONCENTRATE THE RADIATION INTO A
SINGLE ORDER.
24-12-2019V.K. VIKRAM VARMA 66
67. CONTD.
TRANSMISSION GRATING
•IT IS SIMILAR TO DIFFRACTION GRATING, BUT
REFRACTION TAKES PLACE INSTEAD OF REFLECTION,
REFRACTION, PRODUCES REINFORCEMENT.
•WHEN RADIATION TRANSMITTED THROUGH GRATING
REINFORCES WITH THE PARTIALLY REFRACTED
RADIATION
24-12-2019V.K. VIKRAM VARMA 67
69. FILTERS
•A DEVICE THAT ALLOWS LIGHT OF THE REQUIRED
WAVELENGTH TO PASS BUT ABSORBS LIGHT OF OTHER
WAVELENGTH WHOLLY OR PARTIALLY
•SUITABLE FILTER CAN SELECT A DESIRED WAVELENGTH
BAND
•A PARTICULAR FILTER MAY BE USED FOR A SPECIFIC
ANALYSIS,
ABSORPTION FILTERS
INTERFERENCE FILTERS
24-12-2019V.K. VIKRAM VARMA 69
70. CONTD.
ABSORPTION FILTERS
• THESE FILTERS HAVE A BANDWIDTH THAT RANGES FROM 30-250𝑚𝑚
• THE ABSORPTION FILTERS CONSISTS OF COLORED GLASS OR A DYE SUSPENDED
IN GELATIN & SANDWICHED BETWEEN THE TWO GLASS PLATES
• THE COLORED GLASS FILTER HAS THE ADVANTAGE OF GREATER THERMAL
STABILITY.
• EACH INSTRUMENT IS PROVIDED WITH A SET OF 12 FILTERS TO COVER THE
RANGE FROM 390-700𝑚𝑚
• A NARROW SPECTRAL BAND CAN BE OBTAINED BY COUPLING CUT OFF FILTERS
WITH OTHER FILTERS BUT THIS COMBINATION DECREASES THE INTENSITY OF
LIGHT.
24-12-2019V.K. VIKRAM VARMA 70
71. CONTD.
ADVANTAGES
•SIMPLE IN CONSTRUCTION
•CHEAPER, SELECTION OF FILTER
IS EASY
DISADVANTAGES
•LESS ACCURATE, INTENSITY OF
RADIATION BECOME LESS DUE TO
ABSORPTION BY FILTERS.
24-12-2019V.K. VIKRAM VARMA 71
72. CONTD.INTERFERENCE FILTERS
•BASED ON INTERFERENCE PHENOMENON AT DESIRED
WAVELENGTH THUS PERMITTING REJECTION OF UNWANTED
RADIATION BY SELECTIVE REFLECTION & PRODUCING
NARROW BAND.
•IT CONSISTS OF A DIELECTRIC LAYER(EG:CAF2) BETWEEN 2
PARALLEL SILVER FILMS WHICH IS SANDWICHED BY GLASS
PLATE.
•IT HAS A BAND PASS OF 100-150Å & A PEAK TRANSMITTANCE OF
40-60%.
24-12-2019V.K. VIKRAM VARMA 72
73. CONTD.
ADVANATGES
• INEXPENSIVE
• LOWER BAND PASS WHEN COMPARED TO
ABSORPTION FILTERS & HENCE MORE
ACCURATE
DISADVANTAGES
• PEAK TRANSMISSION IS LOW &
BECOMES 50 WHEN ADDITIONAL
FILTERS ARE USED TO CUTS OFF
UNDESIRED WAVE LENGTH.
• THE BAND PASS IS ONLY 10-15𝑐𝑚
24-12-2019V.K. VIKRAM VARMA 73
74. SAMPLE
CONTAINER/CELLS•THE CELLS OR CUVETTES ARE
USED FOR HANDLING LIQUID
SAMPLES.
•THE CELL MAY EITHER BE
RECTANGULAR OR CYLINDRICAL
IN NATURE.
UV REGION- QUARTZ OR FUSED
SILICA
VISIBLE REGION- GLASS
24-12-2019V.K. VIKRAM VARMA 74
75. DETECTORS
•DEVICE WHICH CONVERTS LIGHT ENERGY INTO ELECTRICAL
SIGNALS.
•THE TRANSMITTED RADIATION FALLS ON THE DETECTOR
WHICH DETERMINES THE INTENSITY OF RADIATION
ABSORBED BY SAMPLE.
3 TYPES:
•BARRIER LAYER CELL/PHOTOVOLTAIC CELL
•PHOTOTUBES/ PHOTO EMISSIVE TUBE
•PHOTOMULTIPLIER TUBE
24-12-2019V.K. VIKRAM VARMA 75
76. CONTD.
REQUIREMENTS OF IDEAL DETECTORS:
•IT SHOULD GIVE QUANTITATIVE RESPONSE.
•IT SHOULD HAVE HIGH SENSITIVITY & LOW NOISE LEVEL
•IT SHOULD HAVE A SHORT RESPONSE TIME
•IT SHOULD PROVIDE SIGNAL OR RESPONSE
QUANTITATIVE TO WIDE SPECTRUM OF RADIATION
RECEIVED.
24-12-2019V.K. VIKRAM VARMA 76
77. † BARRIER LAYER/PHOTOVOLTAIC
CELL
•THE DETECTOR HAS A THIN FILM METALLIC LAYER
COATED WITH SILVER OR GOLD & ACT AS ANOTHER
ELECTRODE.
•IT ALSO HAS A METAL BASE PLATE WHICH ACT AS
ANOTHER ELECTRODE.
•THESE 2 LAYERS ARE SEPARATED BY A SEMICONDUCTOR
LAYER OF SELENIUM.
24-12-2019V.K. VIKRAM VARMA 77
78. CONTD.
•THIS CREATES A POTENTIAL
DIFFERENCE BETWEEN 2
ELECTRODES & CAUSES THE FLOW
OF CURRENT.
•WHEN IT IS CONNECTED TO
GALVANOMETER, A FLOW OF
CURRENT OBSERVED WHICH IS
PROPORTIONAL TO THE INTENSITY
& WAVE LENGTH OF LIGHT
FALLING ON IT.
24-12-2019V.K. VIKRAM VARMA 78
79. CONTD.
• WHEN LIGHT RADIATION FALLS ON SELENIUM LAYER, ELECTRONS
BECOME MOBILE & ARE TAKEN UP BY TRANSPARENT METAL LAYER.
ADVANTAGES
• SIMPLE IN DESIGN DO NOT NEED EXTERNAL POWER SUPPLY.
• CHEAPEST & INEXPENSIVE.
DISADVANTAGES
• AMPLIFICATION OF DETECTOR IS NOT POSSIBLE
• LESSER RESPONSE OF DETECTOR WITH LIGHT OTHER THAN BLUE OR
RED LIGHT.
24-12-2019V.K. VIKRAM VARMA 79
80. † PHOTOTUBES/ PHOTO EMISSIVE
TUBE
•CONSISTS OF A EVACUATED GLASS TUBE WITH A PHOTOCATHODE &
COLLECTOR ANODE.
•THE SURFACE OF PHOTOCATHODE IS COATED WITH A LAYER OF
ELEMENTS LIKE CESIUM, SILVER OXIDE OR MIXTURE OF THEM.
•WHEN RADIANT ENERGY FALLS ON PHOTOSENSITIVE CATHODE,
ELECTRONS ARE ATTRACTED TO ANODE CAUSING CURRENT TO
FLOW.
•MORE SENSITIVE COMPARED TO BARRIER LAYER CELL &
THEREFORE WIDELY USED
24-12-2019V.K. VIKRAM VARMA 80
82. † PHOTOMULTIPLIER TUBES
•THE PRINCIPLE EMPLOYED IN THIS DETECTOR IS THAT,
MULTIPLICATION OF PHOTOELECTRONS BY SECONDARY
EMISSION OF ELECTRONS.
•IN A VACCUM TUBE A PRIMARY PHOTO-CATHODE IS FIXED
WHICH RECEIVES RADIATION FROM THE SAMPLE.
•SOME EIGHT TO 10 DYNODES ARE FIXED EACH WITH
INCREASING POTENTIAL OF 75-100V HIGHER THAN
PRECEDING ONE
24-12-2019V.K. VIKRAM VARMA 82
84. CONTD.
• PHOTOMULTIPLIER IS EXTREMELY SENSITIVE TO LIGHT & IS BEST SUITED
WHERE WEAKER OR LOW RADIATION IS RECEIVED
• NEAR THE LAST DYNODE IS FIXED AN ANODE OR ELECTRON COLLECTOR
ELECTRODE
ADVANTAGES
• IDEAL FOR MEASURING WEAK LIGHT INTENSITIES
• FAST IN RESPONSE
DISADVANTAGES
• VERY INTENSE LIGHT CAUSE IRREVERSIBLE DAMAGE OF PHOTO EMISSIVE
SURFACE .HENCE SHOULD BE PROTECTED FROM DAY LIGHT OTHER STRINGER
RADIATIONS
24-12-2019V.K. VIKRAM VARMA 84
85. † TYPES OF
SPECTROPHOTOMETER•A SPECTROPHOTOMETER CAN BE EITHER SINGLE BEAM
OR DOUBLE BEAM.
•IN A SINGLE BEAM INSTRUMENT (SUCH AS THE
SPECTRONIC 20), ALL OF THE LIGHT PASSES THROUGH
THE SAMPLE CELL.
• 𝐼 𝑂 MUST BE MEASURED BY REMOVING THE SAMPLE
•THIS WAS THE EARLIEST DESIGN & IS STILL IN COMMON
USE IN BOTH TEACHING & INDUSTRIAL LABS.
24-12-2019V.K. VIKRAM VARMA 85
86. ۞ SINGLE
BEAM
ADVANTAGES
•THIS TYPE IS CHEAPER.
•THE SYSTEM IS LESS
COMPLICATED
•LOW COST
•HIGH SENSITIVITY
24-12-2019V.K. VIKRAM VARMA 86
CONTD.
87. ۞ SINGLE BEAM INSTRUMENT
24-12-2019V.K. VIKRAM VARMA 87
89. CONTD.
• IN A DOUBLE-BEAM INSTRUMENT, THE LIGHT IS SPLIT
INTO TWO BEAMS BEFORE IT REACHES THE SAMPLE.
•ONE BEAM IS USED AS THE REFERENCE, & THE SECOND
BEAM PASSES THROUGH THE SAMPLE.
•THE REFERENCE BEAM INTENSITY IS TAKEN AS 100%
TRANSMISSION (OR 0 ABSORBANCE), & THE
MEASUREMENT DISPLAYED IS THE RATIO OF THE TWO
BEAM INTENSITIES.
24-12-2019V.K. VIKRAM VARMA 89
90. CONTD.
•MEASUREMENTS FROM DOUBLE BEAM INSTRUMENTS ARE
EASIER & MORE STABLE.
ADVANTAGES
•HIGH STABILITY BECAUSE REFERENCE & SAMPLE ARE
MEASURED VIRTUALLY AT THE SAME MOMENT IN TIME.
DISADVANTAGES
•HIGH COST, LOWER SENSITIVITY
24-12-2019V.K. VIKRAM VARMA 90
92. CHOICE OF SOLVENT
•PROPERTIES OF IDEAL SOLVENT:
IT SHOULD NOT ITSELF ABSORB RADIATIONS IN THE
REGION UNDER INVESTIGATIONS.
IT SHOULD BE LESS POLAR SO THAT IT HAS MINIMUM
INTERACTION WITH THE SOLUTE MOLECULE.
MOST COMMONLY: 95%ETHANOL
CHEAP, GOOD DISSOLVING POWER, DOES NOT ABSORB
RADIATION ABOVE 210𝑛𝑚.
24-12-2019V.K. VIKRAM VARMA 92
93. CONTD.
SOLVENT WAVELENGTH (nm)
WATER 205
METHANOL 210
ETHANOL 210
ETHER 210
CHLOROFORM 245
CHLOROFLOUROCARBON 265
24-12-2019V.K. VIKRAM VARMA 93
E
X
A
M
P
L
E
S
94. SOLVENT EFFECT
•POSITION & INTENSITY OF AN ABSORPTION BAND MAY
SHIFT WHEN THE SPECTRUM IS RECORDED IN
DIFFERENT SOLVENTS.
•DILUTE SAMPLE SOLUTION IS PREFERED FOR ANALYSIS.
•MOST COMMONLY USED SOLVENT: 95%ETHANOL
(BEACAUSE IT IS CHEAP & TRANSPARENT).
24-12-2019V.K. VIKRAM VARMA 94
95. CONTD.
• 𝛼, 𝛽 −UNSATURATED CARBONYL COMPOUNDS SHOW 2
DIFFERENT SHIFTS.
•ABSORPTION BAND MOVES TO SHORTER WAVE
LENGTH(BLUE SHIFT) BY INCREASING THE POLARITY OF
THE SOLVENT.
•GROUND STATE IS MORE POLAR AS COMPARED TO THE
EXICTED STATE.
24-12-2019V.K. VIKRAM VARMA 95
96. EFFECT OF CONECNTRATION, 𝑝𝐻 &
TEMPERATURE
• CONCENTRATION:
NORMALLY EFFECTS THE INTENSITY OF BAND
AT HIGH CONCENTRATION MOLECULAR INTERACTION MAY CAUSE
CHANGE IN POSITION OF ABSORPTION BAND
• 𝒑𝑯: EFFECT OF 𝑝𝐻 ON SPECTRA IS QUITE SIGNIFICANT & RESULT
PRIMARILY FROM SHIFTING OF EQUILIBRIUM BETWEEN 2 DIFFERENT
FORMS.
• TEMPERATURE: IT MAY EFFECT EQUILIBRIUM, WHICH CAN EITHER
CHEMICAL OR PHYSICAL.
24-12-2019V.K. VIKRAM VARMA 96
97. ADVANTAGES & DISADVANTAGES
ADVANTAGES
•HIGH ACCURACY
•EASY TO HANDLE
•SMALL SAMPLE VOLUME IS
REQUIRED
DISADVANTAGES
•DOES NOT WORK WITH
COMPOUNDS THAT DO
NOT ABSORB LIGHT AT
THIS WAVE LENGTH
24-12-2019V.K. VIKRAM VARMA 97
98. APPLICATIONS
• QUALITATIVE & QUANTITATIVE ANALYSIS:
USED FOR CHARACTERISING AROMATIC COMPOUNDS & CONJUGATED
OLEFINS.
TO FIND OUT THE MOLAR CONCENTRATION OF THE SOLUTE UNDER STUDY.
• DETECTION OF ISOMERS ARE POSSIBLE
• DETECTION OF IMPURITIES:
IMPORTANT METHOD TO DETECT IMPURITIES IN ORGANIC SOLVENTS
• CHLORIDE & FLUORIDE QUANTIFICATION
• DETERMINATION OF LEAD & COPPER IN WATER
• DETERMINATION OF SULPHUR DIOXIDE
24-12-2019V.K. VIKRAM VARMA 98
99. REFERENCE
24-12-2019V.K. VIKRAM VARMA 99
• INTRODUCTION TO SPECTROSCOPY BY
PAVIA.
• A TEXTBOOK OF ORGANIC CHEMISTRY
BY BAHL ARUN & BAHL B.S.
• HTTP://WWW.CHEM.UCALGARY.CA/COUR
SES/350/CAREY5TH/CH13/CH13-0.HTML
• WWW.YOUTUBE.COM
• WWW.SLIDESHARE.COM
• WWW.GOOGLE.COM
• HTTPS://WWW.SCIENCEDIRECT.COM/TOP
ICS/EARTH-&-PLANETARY-
SCIENCES/SPECTROSCOPY
• HTTPS://WWW2.CHEMISTRY.MSU.EDU/FA
CULTY/REUSCH/VIRTTXTJML/SPECTRPY
/UV-VIS/UVSPEC.HTM
• HTTPS://WWW.SCIENCEDIRECT.COM/TOP
ICS/CHEMISTRY/UV-VIS-SPECTROSCOPY
• HTTPS://WWW.RESEARCHGATE.NET/PUB
LICATION/46671265_ULTRAVIOLET-
VISIBLE_SPECTROSCOPY
• WWW.WIKIPEDIA.COM