Chemistry 311: Instrumentation Analysis Topic 2: Atomic Spectroscopy. Chemistry 311: Instrumentation Analysis Topic 2: Atomic Spectroscopy

Size: px
Start display at page:

Download "Chemistry 311: Instrumentation Analysis Topic 2: Atomic Spectroscopy. Chemistry 311: Instrumentation Analysis Topic 2: Atomic Spectroscopy"

Transcription

1 Topic 1: Atomic Spectroscopy Text: Chapter 12,13 & 14 Rouessac (~2 weeks) 1.0 Review basic concepts in Spectroscopy 2.0 Atomic Absorption and Graphite Furnace Instruments 3.0 Inductively Coupled Plasmas 4.0 X-ray Fluorescence Winter 2009 Page 1 Electromagnetic Radiation : Wave-Particle Duality Light is a form of Electromagnetic Radiation EM Radiation described by a wave-particle duality mode EM Radiation behaves as a particle with no mass traveling as a sinusoidal wave at the speed of light. EM radiation, as the name suggests, has both Magnetic and Electric field components. These components are at right angles (orthogonal) to each other. Does not travel in a single plane as depicted on paper but rather as a 3D wave. ie., as an extended slinky Winter 2009 Page 2 1

2 Wavelength - λ space taken up by one cycle units of distance normally stated as Å or m or cm, 1 Å = 1 x m = 1 x 10-8 cm Key terms: Amplitude, Period {time required} and Frequency Frequency - ν: # of cycles per sec passing through a given point (units s-1) Frequency determined by source invariant Wavenumber, ν, the reciprocal of the wavelength: ν = 1/λ Power, P, the energy of the beam that reaches a given area per second. The flux of energy per unit time. Power is proportional to Amplitude, A2 Intensity, I, is the power per unit solid angle. Winter 2009 Page 3 Velocity or Speed of Light (c) In vacuum, c is independent of wavelength and is at a maximum value of x 10 8 m/s = constant c In air, velocity of light (v) is only ~0.03% less than c speed of light sometimes reported as 3.00 x 10 8 m/s. Valid in air or vacuum. General expression: c = 3.00 x 10 8 m/s = l ν Consequence of constant ν and c = f(medium)? Index of refraction (η) relates velocity of light in vacuum to medium Index of Refraction : η = c/v Winter 2009 Page 4 2

3 How is Electromagnetic Radiation related to Atomic and Molecular energy? Winter 2009 Page 5 Planck s Quantum Theory: A Quantum is the smallest quantity of energy that can be emitted (or absorbed) in the form of EM. E = h ν where: h is Planck s constant, which is h = 6.63 x J s Energy is always emitted (or absorbed) in whole number multiples of h ν The Photoelectric Effect: Albert Einstein proposed that light is composed of particles, called photons. Each photon has an energy content of; E = h ν Energy above a specific threshold can dislodge electrons from a metal surface. This phenomenon can be used to construct a photon detector. Winter 2009 Page 6 3

4 Winter 2009 Page 7 Energy Storage in Atoms and Molecules: Atoms and molecules have can store energy only in very specific ways. In other words, they have very specific and defined energy states. Since the energy of a photon is defined by it s frequency, only photons with very specific energy can be absorbed by a given atom or molecule. Subsequently, if an atom or molecule is in an excited state and then returns to a less energetic state, photons with specific frequencies will be emitted. E tot = E elec + E vib + E rot + E trans Winter 2009 Page 8 4

5 Winter 2009 Page 9 Basic Instruments and Components Various instruments are used to study absorption, emission, luminescence, etc. of Electromagnetic Radiation (EMR) as a function of wavelength (or frequency): Spectrometer: Measures the intensity of radiation emitted by the sample Spectrophotometer: an instrument with a monochromator to select λ Spectrograph: an instrument with a photographic plate as a detector Photometer: an instrument with a filter to select wavelength range Colorimeter: photometer using the human eye as the detector (visible λ) Fluorometer: an instrument that measures fluorescence. Spectrofluorometer: a Fluorometer with a monochromator Winter 2009 Page 10 5

6 These basic instruments are used to measure 6 phenomena; Absorption Fluorescence Phosphorescence Scattering Emission Chemiluminescence The optical and electronic principle employed in these instruments is basically the same for all the regions of the EMR, however there are some differences in the specific components used in various regions. Winter 2009 Page 11 Basic Instruments and Components Any spectroscopic instrument has five major components: 1. Stable source of radiant energy 2. Transparent container for holding the sample 3. Device that isolates a restricted region for measurement 4. Radiation detector 5. Signal processor or readout Winter 2009 Page 12 6

7 Line Sources for Atomic Absorption: Hollow cathode lamps: Analytical Problem: The smallest Bandwidth that can be obtained by a continuous source is very large compared to atomic absorption lines of nm to nm. Only a fraction of the source beam can be absorbed by an atomic sample large background signal occurs. Analytical Solution: Use atomic emission lines as the source. Winter 2009 Page 13 Line Sources: Electrodeless Discharge lamps: RF or Microwave radiation used to excite metal or salt of material of interest. Intensities of these lamps are one to two orders of magnitude larger than Hollow cathode lamps but performance is not as reliable. Winter 2009 Page 14 7

8 Wavelength Selectors: λ Band and Bandwidth: A narrow, continuous group of λ s. Effective Bandwidth is an indication of the quality of the λ selector. Winter 2009 Page 15 Winter 2009 Page 16 8

9 Wavelength Selectors: Types Filters Interference Filters Interference Wedges Absorption filters Monochromators Prisms Gratings Echellette Grating Concave Holographic Winter 2009 Page 17 Wavelength Selectors: Filters Interference Filters: Limit transference to narrow band. Wavelength passed depends on thickness of dielectric (t) and refractive index (η). UV to IR region. Bandwidth 1.5% to 0.15% of λ. 80% transmission to < 10% trans. Winter 2009 Page 18 9

10 Absorption Filters: Generally less expensive. Normally used in visible region for inexpensive devices. Colored glass or dye suspended in gelatin. Narrow bandwidth low transmission ~10%. Cut-off filters also can be combined. Winter 2009 Page 19 Absorption Filters: Cut-off filters also can be combined. Winter 2009 Page 20 10

11 Winter 2009 Page 21 Winter 2009 Page 22 11

12 Gratings Dispersion achieved through constructive interference Broad face narrow face For constructive interference: nλ = (CB + BD) = d (sin i + sin r) d = distances between blazes; i = incident angle; r = reflected angle Note: n means that a # order lines exist ie. 1st 900 nm, 2nd 450 nm, 3rd 300 nm Winter 2009 Page 23 Winter 2009 Page 24 12

13 Resolving Power of Monochromators: The ability to separate two (images) λ. Resolution of typical benchtop UV/Visible spectrometers 103 to 104. Winter 2009 Page 25 The Electromagnetic Radiation Transducers (Detectors): A radiation transducer is a device that converts the radiation into a quantifiable value. Early transducers were the human eye and photographic plates. Most modern transducers convert signals to an electrical signal. A generic relationship between the radiant power of the radiation and the signal is given by; S = kp + kd Note: kd is also called the dark current. Background current in absence of source Three major categories: Thermal detectors Sense the change in temperature. Examples: Thermoelectric detector; Bolometer; Pyroelectric Photon detectors Respond to incident photon arrival rates rather than to photon energies. Examples: Phototube; Photomultiplier tube (PMT) Multichannel detectors photographic emulsions, arrays of thermal detectors, etc. Winter 2009 Page 26 13

14 Important requirements for detectors: High sensitivity with a low noise level : Short response time. Long term stability to ensure quantitative response. Produces an electronic signal easily amplified. Performance Characteristics of Common Detectors Photon Detectors Phototube The photons strike photoemissive surface of the cathode and transfer energy to loosely bound surface electrons. The electrons escape from the surface and are collected at the anode causing current to flow. Photomultiplier tube (PMT) As in phototubes, an electron is emitted from a photoemissive surface. Ejected electron is accelerated by an electric field; strikes another electron active surface, causing additional emitted electrons. Page 27 Performance Characteristics of Common Detectors Semi-conductor based Devices: Photovoltaic or Barrier-Layer Cells: A simple rugged device containing a thin layer of semiconductor such as selenium coated with silver or gold. Photons are ejected from semiconductor and can flow to silver or gold collector electrode. Range: 350 to 750 nm Advantages: Low cost and rugged, no power required. Disadvantage: Lack of sensitivity at low light levels, difficult to amplify signal, can fatigue with continuous illumination. Silicon Diode Transducers: A silicon chip containing a reverse-biased pn junction. Sensitivity between vacuum phototube and photomultiplier. Range: 190 to 1100 nm Advantages: Low cost and can be miniaturized. Winter 2009 Page 28 14

15 Multichannel Photon detectors: Arrays of detectors usually contained on a semiconductor chip. Three types in common usage: 1) photodiode arrays (PDAs); 2) charge-injection devices (CIDs) and 3) charge-couple devices (CCDs). 2 and 3 are Charge-Transfer Devices (CTDs) Photodiode arrays (PDAs): Series of Silicon Diode Transducers on a single integrated circuit. 64 to 4096 diodes are possible, 1024 most common. Disadvantage: Not as sensitive as photomultiplier. Winter 2009 Page 29 Quantitative Aspects of Spectrochemical Measurements: As seen in the discussion of detectors, most spectroscopic detectors produce a signal that is proportional to the radiant power P of the EM. S = kp + kd The dark current, kd, is usually small and some instruments are equipped with electrical circuits which can reduce this to zero. For emission, luminescence and scattering the radiant power of the EM released is directly proportional to the concentration, ie., S = k C For atomic or molecular absorption, the magnitude that the EM beam is attenuated by the sample is proportional to the concentration. In order to measure the degree of attenuation, two measurements are required, one measuring the incident radiation, P 0, and the other the transmission, P. Winter 2009 Page 30 15

16 Key terms and relations: Winter 2009 Page 31 Beer s Law: Absorbance is directly proportional to the path length, b, the concentration, c, and a proportionality constant called the absorptivity, a, or in other words; A = abc Note: magnitude and units of a dependent on units of b & c When concentration is in Molarity and cell length is in cm, then a is equal to the molar absorptivity, ε, with units L mol -1 cm -1 A = εbc Winter 2009 Page 32 16

17 Operation of a Simple Spectrometer & Relation to Defined 1) Select appropriate wavelength and slit settings (if appropriate) 2) Nullify dark current, kd, by adjusting readout with detector isolated. In other words set to 0% transmission (this is often preset). 3) With solvent blank correct for absorbance of the solvent, scattering, reflectance, etc. by setting Transmission to 100% or zero the absorbance. 4) With sample in read transmission directly. (Note: Absorbance is a log scale) Winter 2009 Page 33 Atomic Absorption (AA) In Atomic Absorption, Sample Solution is spayed into a flame where it is vaporized and converted to atomic atoms. Atomic Atoms can absorb narrow bandwidths of light generated from a Hollow Cathode Tube. Application: Trace analysis of Metals (ppm ppb level) Instrument Cost: ~ $30K - $100K with accessories Winter 2009 Page 34 17

18 Flame Atomization Techniques: Many common steps to the production of gaseous atomic population Winter 2009 Page 35 Atomic Absorption/Emission and Energy Level Diagrams (Note: Na and Mg+ are isoelectronic) Winter 2009 Page 36 18

19 Atomic Absorption/Emission and Energy Level Diagrams Splitting of p orbitals shown in previous overhead is typical. If electron spin magnetic field and orbital motion magnetic field are the same, the energy of the state is higher than if they are different. Analogous to bringing 2 north magnetic fields together. Although, Na and Mg + are isoelectronic, in Mg + the negative electron is being moved further away from a 12 + nucleus rather than a 11 + nucleus, so higher energy is involved. For both Na and Mg+ cases there is 1 electron outside of the closed [Ne] shell. In Figure 8.2 (next page), the energy diagram for atomic Mg is presented. In this case there is two electrons outside of the closed [Ne] shell. If the magnetic spin of these electrons is the same, they are said to be in a triplet state (spins unpaired), if they are opposed, they are in a singlet state (spins paired). If spins are paired, the effects of magnetic electron and magnetic orbital spin splitting cancel and so the p-splitting effect is cancelled. However, in triplet states, all the p, d and f states are split. Therefore, many transitions are possible Winter 2009 Page 37 Winter 2009 Page 38 19

20 9/30/09 Winter 2009 Page 39 Atomic Energy Level Diagrams As depicted by the darker lines in the previous slides; Some transitions are more probable than others. The nature of the allowed and favored transitions is governed by a complex set of selection rules, in which some types of transitions are forbidden. For example, singlet - singlet transitions are much more probable than singlet triplet transitions. As a result the emission or absorption lines of these transitions are much more intense. As indicated by the previous diagrams, the complexity of the Energy Level diagrams increase with the number of electrons outside the closed shell. For a simple one electron alkali metal such as Lithium there is only 30 observed spectra, for magnesium there is 173, for Iron there is As we will discuss later, the number of observed emission lines is much lower in lower energy atomizers such as flames. Winter 2009 Page 40 20

25 Instruments for Optical Spectrometry

25 Instruments for Optical Spectrometry 25 Instruments for Optical Spectrometry 25A INSTRUMENT COMPONENTS (1) source of radiant energy (2) wavelength selector (3) sample container (4) detector (5) signal processor and readout (a) (b) (c) Fig.

More information

Because light behaves like a wave, we can describe it in one of two ways by its wavelength or by its frequency.

Because light behaves like a wave, we can describe it in one of two ways by its wavelength or by its frequency. Light We can use different terms to describe light: Color Wavelength Frequency Light is composed of electromagnetic waves that travel through some medium. The properties of the medium determine how light

More information

Reference literature. (See: CHEM 2470 notes, Module 8 Textbook 6th ed., Chapters )

Reference literature. (See: CHEM 2470 notes, Module 8 Textbook 6th ed., Chapters ) September 17, 2018 Reference literature (See: CHEM 2470 notes, Module 8 Textbook 6th ed., Chapters 13-14 ) Reference.: https://slideplayer.com/slide/8354408/ Spectroscopy Usual Wavelength Type of Quantum

More information

Course Details. Analytical Techniques Based on Optical Spectroscopy. Course Details. Textbook. SCCH 211: Analytical Chemistry I

Course Details. Analytical Techniques Based on Optical Spectroscopy. Course Details. Textbook. SCCH 211: Analytical Chemistry I SCCH 211: Analytical Chemistry I Analytical Techniques Based on Optical Spectroscopy Course Details September 22 October 10 September 22 November 7 November 17 December 1 Topic Period Introduction to Spectrometric

More information

Chemistry 311: Topic 2 - Atomic Spectroscopy Topic 2: Spectroscopy:

Chemistry 311: Topic 2 - Atomic Spectroscopy Topic 2: Spectroscopy: Topic 2: Spectroscopy: Introductory Theory Basic Components Qualitative and Quantitative applications Atomic Spectroscopy Molecular Spectroscopy Electromagnetic Radiation : Wave-Particle Duality Light

More information

2001 Spectrometers. Instrument Machinery. Movies from this presentation can be access at

2001 Spectrometers. Instrument Machinery. Movies from this presentation can be access at 2001 Spectrometers Instrument Machinery Movies from this presentation can be access at http://www.shsu.edu/~chm_tgc/sounds/sound.html Chp20: 1 Optical Instruments Instrument Components Components of various

More information

Skoog Chapter 6 Introduction to Spectrometric Methods

Skoog Chapter 6 Introduction to Spectrometric Methods Skoog Chapter 6 Introduction to Spectrometric Methods General Properties of Electromagnetic Radiation (EM) Wave Properties of EM Quantum Mechanical Properties of EM Quantitative Aspects of Spectrochemical

More information

Spectroscopy: Introduction. Required reading Chapter 18 (pages ) Chapter 20 (pages )

Spectroscopy: Introduction. Required reading Chapter 18 (pages ) Chapter 20 (pages ) Spectroscopy: Introduction Required reading Chapter 18 (pages 378-397) Chapter 20 (pages 424-449) Spectrophotometry is any procedure that uses light to measure chemical concentrations Properties of Light

More information

10/2/2008. hc λ. νλ =c. proportional to frequency. Energy is inversely proportional to wavelength And is directly proportional to wavenumber

10/2/2008. hc λ. νλ =c. proportional to frequency. Energy is inversely proportional to wavelength And is directly proportional to wavenumber CH217 Fundamentals of Analytical Chemistry Module Leader: Dr. Alison Willows Electromagnetic spectrum Properties of electromagnetic radiation Many properties of electromagnetic radiation can be described

More information

Analytical Spectroscopy Review

Analytical Spectroscopy Review Analytical Spectroscopy Review λ = wavelength ν = frequency V = velocity = ν x λ = 2.998 x 10 8 m/sec = c (in a vacuum) ν is determined by source and does not change as wave propogates, but V can change

More information

Instrumental Analysis: Spectrophotometric Methods

Instrumental Analysis: Spectrophotometric Methods Instrumental Analysis: Spectrophotometric Methods 2007 By the end of this part of the course, you should be able to: Understand interaction between light and matter (absorbance, excitation, emission, luminescence,fluorescence,

More information

Chem 434 -Instrumental Analysis Hour Exam 1

Chem 434 -Instrumental Analysis Hour Exam 1 Do any 8 of the following 9 problems Name: Chem 434 -Instrumental Analysis Hour Exam 1 +2 1. A 25.0 ml sample containing Cu gave an instrument reading of 23.6 units (corrected for a blank). When exactly

More information

Ch 313 FINAL EXAM OUTLINE Spring 2010

Ch 313 FINAL EXAM OUTLINE Spring 2010 Ch 313 FINAL EXAM OUTLINE Spring 2010 NOTE: Use this outline at your own risk sometimes a topic is omitted that you are still responsible for. It is meant to be a study aid and is not meant to be a replacement

More information

Chapter 18. Fundamentals of Spectrophotometry. Properties of Light

Chapter 18. Fundamentals of Spectrophotometry. Properties of Light Chapter 18 Fundamentals of Spectrophotometry Properties of Light Electromagnetic Radiation energy radiated in the form of a WAVE caused by an electric field interacting with a magnetic field result of

More information

Atomic Absorption Spectroscopy

Atomic Absorption Spectroscopy CH 2252 Instrumental Methods of Analysis Unit IV Atomic Absorption Spectroscopy Dr. M. Subramanian Associate Professor Department of Chemical Engineering Sri Sivasubramaniya Nadar College of Engineering

More information

CHEM*3440. Photon Energy Units. Spectrum of Electromagnetic Radiation. Chemical Instrumentation. Spectroscopic Experimental Concept.

CHEM*3440. Photon Energy Units. Spectrum of Electromagnetic Radiation. Chemical Instrumentation. Spectroscopic Experimental Concept. Spectrum of Electromagnetic Radiation Electromagnetic radiation is light. Different energy light interacts with different motions in molecules. CHEM*344 Chemical Instrumentation Topic 7 Spectrometry Radiofrequency

More information

Chemistry 311: Instrumentation Analysis Topic 2: Atomic Spectroscopy. Chemistry 311: Instrumentation Analysis Topic 2: Atomic Spectroscopy

Chemistry 311: Instrumentation Analysis Topic 2: Atomic Spectroscopy. Chemistry 311: Instrumentation Analysis Topic 2: Atomic Spectroscopy Topic 2b: X-ray Fluorescence Spectrometry Text: Chapter 12 Rouessac (1 week) 4.0 X-ray Fluorescence Download, read and understand EPA method 6010C ICP-OES Winter 2009 Page 1 Atomic X-ray Spectrometry Fundamental

More information

Introduction to Spectroscopic methods

Introduction to Spectroscopic methods Introduction to Spectroscopic methods Spectroscopy: Study of interaction between light* and matter. Spectrometry: Implies a quantitative measurement of intensity. * More generally speaking electromagnetic

More information

Ultraviolet-Visible and Infrared Spectrophotometry

Ultraviolet-Visible and Infrared Spectrophotometry Ultraviolet-Visible and Infrared Spectrophotometry Ahmad Aqel Ifseisi Assistant Professor of Analytical Chemistry College of Science, Department of Chemistry King Saud University P.O. Box 2455 Riyadh 11451

More information

Overview of Spectroscopy

Overview of Spectroscopy Overview of Spectroscopy A. Definition: Interaction of EM Radiation with Matter We see objects because they remit some part of the light falling on them from a source. We function as reflection/ transmission

More information

Lecture 0. NC State University

Lecture 0. NC State University Chemistry 736 Lecture 0 Overview NC State University Overview of Spectroscopy Electronic states and energies Transitions between states Absorption and emission Electronic spectroscopy Instrumentation Concepts

More information

Molecular Luminescence Spectroscopy

Molecular Luminescence Spectroscopy Molecular Luminescence Spectroscopy In Molecular Luminescence Spectrometry ( MLS ), molecules of the analyte in solution are excited to give a species whose emission spectrum provides information for qualitative

More information

R O Y G B V. Spin States. Outer Shell Electrons. Molecular Rotations. Inner Shell Electrons. Molecular Vibrations. Nuclear Transitions

R O Y G B V. Spin States. Outer Shell Electrons. Molecular Rotations. Inner Shell Electrons. Molecular Vibrations. Nuclear Transitions Spin States Molecular Rotations Molecular Vibrations Outer Shell Electrons Inner Shell Electrons Nuclear Transitions NMR EPR Microwave Absorption Spectroscopy Infrared Absorption Spectroscopy UV-vis Absorption,

More information

9/28/10. Visible and Ultraviolet Molecular Spectroscopy - (S-H-C Chapters 13-14) Valence Electronic Structure. n σ* transitions

9/28/10. Visible and Ultraviolet Molecular Spectroscopy - (S-H-C Chapters 13-14) Valence Electronic Structure. n σ* transitions Visible and Ultraviolet Molecular Spectroscopy - (S-H-C Chapters 13-14) Electromagnetic Spectrum - Molecular transitions Widely used in chemistry. Perhaps the most widely used in Biological Chemistry.

More information

Spectroscopy Problem Set February 22, 2018

Spectroscopy Problem Set February 22, 2018 Spectroscopy Problem Set February, 018 4 3 5 1 6 7 8 1. In the diagram above which of the following represent vibrational relaxations? 1. Which of the following represent an absorbance? 3. Which of following

More information

Spectroscopy. Page 1 of 8 L.Pillay (2012)

Spectroscopy. Page 1 of 8 L.Pillay (2012) Spectroscopy Electromagnetic radiation is widely used in analytical chemistry. The identification and quantification of samples using electromagnetic radiation (light) is called spectroscopy. Light has

More information

3 - Atomic Absorption Spectroscopy

3 - Atomic Absorption Spectroscopy 3 - Atomic Absorption Spectroscopy Introduction Atomic-absorption (AA) spectroscopy uses the absorption of light to measure the concentration of gas-phase atoms. Since samples are usually liquids or solids,

More information

Complete the following. Clearly mark your answers. YOU MUST SHOW YOUR WORK TO RECEIVE CREDIT.

Complete the following. Clearly mark your answers. YOU MUST SHOW YOUR WORK TO RECEIVE CREDIT. CHEM 322 Name Exam 3 Spring 2013 Complete the following. Clearly mark your answers. YOU MUST SHOW YOUR WORK TO RECEIVE CREDIT. Warm-up (3 points each). 1. In Raman Spectroscopy, molecules are promoted

More information

If you like us, please share us on social media. The latest UCD Hyperlibrary newsletter is now complete, check it out.

If you like us, please share us on social media. The latest UCD Hyperlibrary newsletter is now complete, check it out. Sign In Forgot Password Register username username password password Sign In If you like us, please share us on social media. The latest UCD Hyperlibrary newsletter is now complete, check it out. ChemWiki

More information

Skoog Chapter 7 Components of Optical Instruments

Skoog Chapter 7 Components of Optical Instruments Skoog Chapter 7 Components of Optical Instruments General Design of Optical Instruments Sources of Radiation Wavelength Selectors (Filters, Monochromators, Interferometers) Sample Containers Radiation

More information

Chapter 17: Fundamentals of Spectrophotometry

Chapter 17: Fundamentals of Spectrophotometry Chapter 17: Fundamentals of Spectrophotometry Spectroscopy: the science that deals with interactions of matter with electromagnetic radiation or other forms energy acoustic waves, beams of particles such

More information

Ultraviolet-Visible and Infrared Spectrophotometry

Ultraviolet-Visible and Infrared Spectrophotometry Ultraviolet-Visible and Infrared Spectrophotometry Ahmad Aqel Ifseisi Assistant Professor of Analytical Chemistry College of Science, Department of Chemistry King Saud University P.O. Box 2455 Riyadh 11451

More information

Analytical Chemistry II

Analytical Chemistry II Analytical Chemistry II L4: Signal processing (selected slides) Computers in analytical chemistry Data acquisition Printing final results Data processing Data storage Graphical display https://www.creativecontrast.com/formal-revolution-of-computer.html

More information

Wavelength λ Velocity v. Electric Field Strength Amplitude A. Time t or Distance x time for 1 λ to pass fixed point. # of λ passing per s ν= 1 p

Wavelength λ Velocity v. Electric Field Strength Amplitude A. Time t or Distance x time for 1 λ to pass fixed point. # of λ passing per s ν= 1 p Introduction to Spectroscopy (Chapter 6) Electromagnetic radiation (wave) description: Wavelength λ Velocity v Electric Field Strength 0 Amplitude A Time t or Distance x Period p Frequency ν time for 1

More information

Chemistry Instrumental Analysis Lecture 8. Chem 4631

Chemistry Instrumental Analysis Lecture 8. Chem 4631 Chemistry 4631 Instrumental Analysis Lecture 8 UV to IR Components of Optical Basic components of spectroscopic instruments: stable source of radiant energy transparent container to hold sample device

More information

Reflection = EM strikes a boundary between two media differing in η and bounces back

Reflection = EM strikes a boundary between two media differing in η and bounces back Reflection = EM strikes a boundary between two media differing in η and bounces back Incident ray θ 1 θ 2 Reflected ray Medium 1 (air) η = 1.00 Medium 2 (glass) η = 1.50 Specular reflection = situation

More information

What is spectroscopy?

What is spectroscopy? Absorption Spectrum What is spectroscopy? Studying the properties of matter through its interaction with different frequency components of the electromagnetic spectrum. With light, you aren t looking directly

More information

INTRODUCTION Atomic fluorescence spectroscopy ( AFS ) depends on the measurement of the emission ( fluorescence ) emitted from gasphase analyte atoms

INTRODUCTION Atomic fluorescence spectroscopy ( AFS ) depends on the measurement of the emission ( fluorescence ) emitted from gasphase analyte atoms INTRODUCTION Atomic fluorescence spectroscopy ( AFS ) depends on the measurement of the emission ( fluorescence ) emitted from gasphase analyte atoms that have been excited to higher energy levels by absorption

More information

MOLECULAR AND ATOMIC SPECTROSCOPY

MOLECULAR AND ATOMIC SPECTROSCOPY MOLECULAR AND ATOMIC SPECTROSCOPY 1. General Background on Molecular Spectroscopy 3 1.1. Introduction 3 1.2. Beer s Law 5 1.3. Instrumental Setup of a Spectrophotometer 12 1.3.1. Radiation Sources 13 1.3.2.

More information

CHAPTER 2. Preliminaries A Review of Optical Physics

CHAPTER 2. Preliminaries A Review of Optical Physics CHAPTER 2 Preliminaries A Review of Optical Physics 1.1 Introduction The concentration of metal species in a variety of sample matrices has frequently been measured by observing an atom s interaction with

More information

Chapter 4 Ultraviolet and visible spectroscopy Molecular Spectrophotometry

Chapter 4 Ultraviolet and visible spectroscopy Molecular Spectrophotometry Chapter 4 Ultraviolet and visible spectroscopy Molecular Spectrophotometry Properties of light Electromagnetic radiation and electromagnetic spectrum Absorption of light Beer s law Limitation of Beer s

More information

Stellar Astrophysics: The Interaction of Light and Matter

Stellar Astrophysics: The Interaction of Light and Matter Stellar Astrophysics: The Interaction of Light and Matter The Photoelectric Effect Methods of electron emission Thermionic emission: Application of heat allows electrons to gain enough energy to escape

More information

Chem 155 Midterm Exam Page 1 of 10 Spring 2010 Terrill

Chem 155 Midterm Exam Page 1 of 10 Spring 2010 Terrill Chem 155 Midterm Exam Page 1 of 10 ame Signature 1. Mercury (Hg) is is believed to be hazardous to human neurological health at extremely low concentrations. Fortunately EPA Method 45.7 cold vapor atomic

More information

Reference. What is spectroscopy? What is Light? / EMR 11/15/2015. Principles of Spectroscopy. Processes in Spectroscopy

Reference. What is spectroscopy? What is Light? / EMR 11/15/2015. Principles of Spectroscopy. Processes in Spectroscopy Chapter 2 Principles of Spectroscopy EST 3203 Instrumental Analysis Rezaul Karim Environmental Science and Technology Jessore Science and Technology University Principles of Spectroscopy Electromagnetic

More information

Atomization. In Flame Emission

Atomization. In Flame Emission FLAME SPECTROSCOPY The concentration of an element in a solution is determined by measuring the absorption, emission or fluorescence of electromagnetic by its monatomic particles in gaseous state in the

More information

Chapter 10. Spectroscopic Methods. An early example of a colorimetric analysis is Nessler s method for ammonia, which was.

Chapter 10. Spectroscopic Methods. An early example of a colorimetric analysis is Nessler s method for ammonia, which was. Chapter 10 Spectroscopic Methods Chapter Overview Section 10A Overview of Spectroscopy Section 10B Spectroscopy Based on Absorption Section 10C UV/Vis and IR Spectroscopy Section 10D Atomic Absorption

More information

The Fundamentals of Spectroscopy: Theory BUILDING BETTER SCIENCE AGILENT AND YOU

The Fundamentals of Spectroscopy: Theory BUILDING BETTER SCIENCE AGILENT AND YOU The Fundamentals of Spectroscopy: Theory BUILDING BETTER SCIENCE AGILENT AND YOU 1 Agilent is committed to the educational community and is willing to provide access to company-owned material. This slide

More information

Chemistry 524--Final Exam--Keiderling May 4, :30 -?? pm SES

Chemistry 524--Final Exam--Keiderling May 4, :30 -?? pm SES Chemistry 524--Final Exam--Keiderling May 4, 2011 3:30 -?? pm -- 4286 SES Please answer all questions in the answer book provided. Calculators, rulers, pens and pencils are permitted. No open books or

More information

Chapter 4 Scintillation Detectors

Chapter 4 Scintillation Detectors Med Phys 4RA3, 4RB3/6R03 Radioisotopes and Radiation Methodology 4-1 4.1. Basic principle of the scintillator Chapter 4 Scintillation Detectors Scintillator Light sensor Ionizing radiation Light (visible,

More information

Spectrophotometry. Introduction

Spectrophotometry. Introduction Spectrophotometry Spectrophotometry is a method to measure how much a chemical substance absorbs light by measuring the intensity of light as a beam of light passes through sample solution. The basic principle

More information

FLAME PHOTOMETRY AIM INTRODUCTION

FLAME PHOTOMETRY AIM INTRODUCTION FLAME PHOTOMETRY AIM INTRODUCTION Atomic spectroscopy is based on the absorption, emission or fluorescence process of light by atoms or elementary ions. Information for atomic scale is obtained in two

More information

Design and Development of a Smartphone Based Visible Spectrophotometer for Analytical Applications

Design and Development of a Smartphone Based Visible Spectrophotometer for Analytical Applications Design and Development of a Smartphone Based Visible Spectrophotometer for Analytical Applications Bedanta Kr. Deka, D. Thakuria, H. Bora and S. Banerjee # Department of Physicis, B. Borooah College, Ulubari,

More information

Sample Copyright. Academic Group ATOMIC STRUCTURE 1. Topics covered in this chapter:

Sample Copyright. Academic Group ATOMIC STRUCTURE 1. Topics covered in this chapter: ATOMIC STRUCTURE Topics covered in this chapter:. Structure of the Atom.2 Atomic Number, Mass Number.3 Isotopes.4 The Mass Spectrometer.5 Atomic Structure and Light Spectra.6 Electron Arrangements in Atoms.7

More information

Chemistry Instrumental Analysis Lecture 2. Chem 4631

Chemistry Instrumental Analysis Lecture 2. Chem 4631 Chemistry 4631 Instrumental Analysis Lecture 2 Electromagnetic Radiation Can be described by means of a classical sinusoidal wave model. Oscillating electric and magnetic field. (Wave model) wavelength,

More information

Chemistry 121: Atomic and Molecular Chemistry Topic 3: Atomic Structure and Periodicity

Chemistry 121: Atomic and Molecular Chemistry Topic 3: Atomic Structure and Periodicity Text Chapter 2, 8 & 9 3.1 Nature of light, elementary spectroscopy. 3.2 The quantum theory and the Bohr atom. 3.3 Quantum mechanics; the orbital concept. 3.4 Electron configurations of atoms 3.5 The periodic

More information

Questions on Instrumental Methods of Analysis

Questions on Instrumental Methods of Analysis Questions on Instrumental Methods of Analysis 1. Which one of the following techniques can be used for the detection in a liquid chromatograph? a. Ultraviolet absorbance or refractive index measurement.

More information

II. Spectrophotometry (Chapters 17, 19, 20)

II. Spectrophotometry (Chapters 17, 19, 20) II. Spectrophotometry (Chapters 17, 19, 20) FUNDAMENTALS (Chapter 17) Spectrophotometry: any technique that uses light to measure concentrations (here: U and visible - ~190 800 nm) c = 2.99792 x 10 8 m/s

More information

Spectrochemical methods

Spectrochemical methods Spectrochemical methods G. Galbács The interactions of radiations and matter are the subject of spectroscopy py or spectrochemical methods (also called spectrometry). Spectrochemical methods usually measure

More information

Atomic Absorption Spectrophotometry. Presentation by, Mrs. Sangita J. Chandratre Department of Microbiology M. J. college, Jalgaon

Atomic Absorption Spectrophotometry. Presentation by, Mrs. Sangita J. Chandratre Department of Microbiology M. J. college, Jalgaon Atomic Absorption Spectrophotometry Presentation by, Mrs. Sangita J. Chandratre Department of Microbiology M. J. college, Jalgaon Defination In analytical chemistry, Atomic absorption spectroscopy is a

More information

Chemistry Instrumental Analysis Lecture 19 Chapter 12. Chem 4631

Chemistry Instrumental Analysis Lecture 19 Chapter 12. Chem 4631 Chemistry 4631 Instrumental Analysis Lecture 19 Chapter 12 There are three major techniques used for elemental analysis: Optical spectrometry Mass spectrometry X-ray spectrometry X-ray Techniques include:

More information

Chapter 10. Spectroscopic Methods. An early example of a colorimetric analysis is Nessler s method for ammonia, which was.

Chapter 10. Spectroscopic Methods. An early example of a colorimetric analysis is Nessler s method for ammonia, which was. Chapter 10 Spectroscopic Methods Chapter Overview 10A Overview of Spectroscopy 10B Spectroscopy Based on Absorption 10C UV/Vis and IR Spectroscopy 10D Atomic Absorption Spectroscopy 10E Emission Spectroscopy

More information

high temp ( K) Chapter 20: Atomic Spectroscopy

high temp ( K) Chapter 20: Atomic Spectroscopy high temp (2000-6000K) Chapter 20: Atomic Spectroscopy 20-1. An Overview Most compounds Atoms in gas phase high temp (2000-6000K) (AES) (AAS) (AFS) sample Mass-to-charge (ICP-MS) Atomic Absorption experiment

More information

Model Answer (Paper code: AR-7112) M. Sc. (Physics) IV Semester Paper I: Laser Physics and Spectroscopy

Model Answer (Paper code: AR-7112) M. Sc. (Physics) IV Semester Paper I: Laser Physics and Spectroscopy Model Answer (Paper code: AR-7112) M. Sc. (Physics) IV Semester Paper I: Laser Physics and Spectroscopy Section I Q1. Answer (i) (b) (ii) (d) (iii) (c) (iv) (c) (v) (a) (vi) (b) (vii) (b) (viii) (a) (ix)

More information

Advanced Spectroscopy Laboratory

Advanced Spectroscopy Laboratory Advanced Spectroscopy Laboratory - Raman Spectroscopy - Emission Spectroscopy - Absorption Spectroscopy - Raman Microscopy - Hyperspectral Imaging Spectroscopy FERGIELAB TM Raman Spectroscopy Absorption

More information

Chapter 17: Fundamentals of Spectrophotometry

Chapter 17: Fundamentals of Spectrophotometry Chapter 17: Fundamentals of Spectrophotometry Spectroscopy: the science that deals with interactions of matter with electromagnetic radiation or other forms energy acoustic waves, beams of particles such

More information

Chapter 13 An Introduction to Ultraviolet/Visible Molecular Absorption Spectrometry

Chapter 13 An Introduction to Ultraviolet/Visible Molecular Absorption Spectrometry Chapter 13 An Introduction to Ultraviolet/Visible Molecular Absorption Spectrometry 13A Measurement Of Transmittance and Absorbance Absorption measurements based upon ultraviolet and visible radiation

More information

Chapter 6 Electronic Structure of Atoms

Chapter 6 Electronic Structure of Atoms Chapter 6 Electronic Structure of Atoms What is the origin of color in matter? Demo: flame tests What does this have to do with the atom? Why are atomic properties periodic? 6.1 The Wave Nature of Light

More information

Compact Knowledge: Absorbance Spectrophotometry. Flexible. Reliable. Personal.

Compact Knowledge: Absorbance Spectrophotometry. Flexible. Reliable. Personal. L A B O R A T O R Y C O M P E T E N C E Compact Knowledge: Absorbance Spectrophotometry Flexible. Reliable. Personal. The interaction of light with molecules is an essential and well accepted technique

More information

JABLONSKI DIAGRAM 2/15/16

JABLONSKI DIAGRAM 2/15/16 INDICATE THE EXCITED AND GROUND SINGLET AND TRIPLET STATES. INDICATE THE FOLLOWING TRANSITIONS: ABSORPTION, FLUORESCENCE, PHOSPHORESCENCE, NONRADIATIVE DECAY, INTERNAL CONVERSION AND INTERSYSTEM CROSSING.

More information

Classification of spectroscopic methods

Classification of spectroscopic methods Introduction Spectroscopy is the study of the interaction between the electromagnetic radiation and the matter. Spectrophotometry is the measurement of these interactions i.e. the measurement of the intensity

More information

2101 Atomic Spectroscopy

2101 Atomic Spectroscopy 2101 Atomic Spectroscopy Atomic identification Atomic spectroscopy refers to the absorption and emission of ultraviolet to visible light by atoms and monoatomic ions. It is best used to analyze metals.

More information

EMISSION SPECTROSCOPY

EMISSION SPECTROSCOPY IFM The Department of Physics, Chemistry and Biology LAB 57 EMISSION SPECTROSCOPY NAME PERSONAL NUMBER DATE APPROVED I. OBJECTIVES - Understand the principle of atomic emission spectra. - Know how to acquire

More information

Chapter 5 Light and Matter

Chapter 5 Light and Matter Chapter 5 Light and Matter Stars and galaxies are too far for us to send a spacecraft or to visit (in our lifetimes). All we can receive from them is light But there is much we can learn (composition,

More information

Instrumental Chemical Analysis

Instrumental Chemical Analysis L6 page 1 Instrumental Chemical Analysis Ultraviolet and visible spectroscopy Dr. Ahmad Najjar Philadelphia University Faculty of Pharmacy Department of Pharmaceutical Sciences 2 nd semester, 2016/2017

More information

Instrumental Chemical Analysis

Instrumental Chemical Analysis L6 page 1 Instrumental Chemical Analysis Ultraviolet and visible spectroscopy Dr. Ahmad Najjar Philadelphia University Faculty of Pharmacy Department of Pharmaceutical Sciences 2 nd semester, 2016/2017

More information

Outline of Recombinant DNA technology. Application of UV spectroscopy in recombinant DNA technology

Outline of Recombinant DNA technology. Application of UV spectroscopy in recombinant DNA technology NIKHIL.K.POTDUKHE Outline of UV spectrophotometer Outline of Recombinant DNA technology Application of UV spectroscopy in recombinant DNA technology References Lambert law: When a beam of light is allowed

More information

Taking fingerprints of stars, galaxies, and interstellar gas clouds

Taking fingerprints of stars, galaxies, and interstellar gas clouds - - Taking fingerprints of stars, galaxies, and interstellar gas clouds Absorption and emission from atoms, ions, and molecules Periodic Table of Elements The universe is mostly hydrogen H and helium He

More information

Introduction to Photovoltaics

Introduction to Photovoltaics INTRODUCTION Objectives Understand the photovoltaic effect. Understand the properties of light. Describe frequency and wavelength. Understand the factors that determine available light energy. Use software

More information

Chapter 5 Electrons In Atoms

Chapter 5 Electrons In Atoms Chapter 5 Electrons In Atoms 5.1 Revising the Atomic Model 5.2 Electron Arrangement in Atoms 5.3 Atomic Emission Spectra and the Quantum Mechanical Model 1 Copyright Pearson Education, Inc., or its affiliates.

More information

Chemistry Instrumental Analysis Lecture 17. Chem 4631

Chemistry Instrumental Analysis Lecture 17. Chem 4631 Chemistry 4631 Instrumental Analysis Lecture 17 Introduction to Optical Atomic Spectrometry From molecular to elemental analysis there are three major techniques used for elemental analysis: Optical spectrometry

More information

Absorption spectrometry summary

Absorption spectrometry summary Absorption spectrometry summary Rehearsal: Properties of light (electromagnetic radiation), dual nature light matter interactions (reflection, transmission, absorption, scattering) Absorption phenomena,

More information

Chapter 15 Molecular Luminescence Spectrometry

Chapter 15 Molecular Luminescence Spectrometry Chapter 15 Molecular Luminescence Spectrometry Two types of Luminescence methods are: 1) Photoluminescence, Light is directed onto a sample, where it is absorbed and imparts excess energy into the material

More information

Chemistry Instrumental Analysis Lecture 3. Chem 4631

Chemistry Instrumental Analysis Lecture 3. Chem 4631 Chemistry 4631 Instrumental Analysis Lecture 3 Quantum Transitions The energy of a photon can also be transferred to an elementary particle by adsorption if the energy of the photon exactly matches the

More information

24 Introduction to Spectrochemical Methods

24 Introduction to Spectrochemical Methods 24 Introduction to Spectrochemical Methods Spectroscopic method: based on measurement of the electromagnetic radiation produced or absorbed by analytes. electromagnetic radiation: include γ-ray, X-ray,

More information

Photochemical principles

Photochemical principles Chapter 1 Photochemical principles Dr. Suzan A. Khayyat 1 Photochemistry Photochemistry is concerned with the absorption, excitation and emission of photons by atoms, atomic ions, molecules, molecular

More information

Preview from Notesale.co.uk Page 4 of 35

Preview from Notesale.co.uk Page 4 of 35 field 64 If a dielectric is inserted b/w the plates of a charged capacitor, its Remains Becomes infinite capacitance constant decreases increases 65 Selenium is an insulator in the dark but when exposed

More information

Ch. 6: Introduction to Spectroscopic methods

Ch. 6: Introduction to Spectroscopic methods Ch. 6: Introduction to Spectroscopic methods Spectroscopy: A branch of science that studies the interaction between EM radiation and matter. Spectrometry and Spectrometric methods : Measurement of the

More information

Revision Guide. Chapter 7 Quantum Behaviour

Revision Guide. Chapter 7 Quantum Behaviour Revision Guide Chapter 7 Quantum Behaviour Contents CONTENTS... 2 REVISION CHECKLIST... 3 REVISION NOTES... 4 QUANTUM BEHAVIOUR... 4 Random arrival of photons... 4 Photoelectric effect... 5 PHASE AN PHASORS...

More information

Unit 3. Chapter 4 Electrons in the Atom. Niels Bohr s Model. Recall the Evolution of the Atom. Bohr s planetary model

Unit 3. Chapter 4 Electrons in the Atom. Niels Bohr s Model. Recall the Evolution of the Atom. Bohr s planetary model Unit 3 Chapter 4 Electrons in the Atom Electrons in the Atom (Chapter 4) & The Periodic Table/Trends (Chapter 5) Niels Bohr s Model Recall the Evolution of the Atom He had a question: Why don t the electrons

More information

World Journal of Pharmaceutical Research SJIF Impact Factor 8.074

World Journal of Pharmaceutical Research SJIF Impact Factor 8.074 SJIF Impact Factor 8.074 Volume 7, Issue 11, 1170-1180. Review Article ISSN 2277 7105 DEVELOPMENT AND OPTIMIZATION OF UV-VIS SPECTROSCOPY - A REVIEW Govinda Verma* and Dr. Manish Mishra Shri Guru Ram Rai

More information

1 P a g e h t t p s : / / w w w. c i e n o t e s. c o m / Physics (A-level)

1 P a g e h t t p s : / / w w w. c i e n o t e s. c o m / Physics (A-level) 1 P a g e h t t p s : / / w w w. c i e n o t e s. c o m / Physics (A-level) Electromagnetic induction (Chapter 23): For a straight wire, the induced current or e.m.f. depends on: The magnitude of the magnetic

More information

10. Wavelength measurement using prism spectroscopy

10. Wavelength measurement using prism spectroscopy Spk 0. Wavelength measurement using prism spectroscopy 0. Introduction The study of emitted spectra of electromagnetic waves by excited atoms makes for one of the most important methods to investigate

More information

Lecture 3: Light absorbance

Lecture 3: Light absorbance Lecture 3: Light absorbance Perturbation Response 1 Light in Chemistry Light Response 0-3 Absorbance spectrum of benzene 2 Absorption Visible Light in Chemistry S 2 S 1 Fluorescence http://www.microscopyu.com

More information

Professor K. Atomic structure

Professor K. Atomic structure Professor K Atomic structure Review Reaction- the formation and breaking of chemical bonds Bond- a transfer or sharing of electrons Electrons Abbreviated e - What are they? How were they discovered? Early

More information

高等食品分析 (Advanced Food Analysis) I. SPECTROSCOPIC METHODS *Instrumental methods: 1. Spectroscopic methods (spectroscopy): a) Electromagnetic radiation

高等食品分析 (Advanced Food Analysis) I. SPECTROSCOPIC METHODS *Instrumental methods: 1. Spectroscopic methods (spectroscopy): a) Electromagnetic radiation *Instrumental methods: 1. Spectroscopic methods (spectroscopy): a) Electromagnetic radiation (EMR): γ-ray emission X-Ray absorption, emission, fluorescence and diffraction Vacuum ultraviolet (UV) absorption

More information

The Photoelectric Effect

The Photoelectric Effect Stellar Astrophysics: The Interaction of Light and Matter The Photoelectric Effect Methods of electron emission Thermionic emission: Application of heat allows electrons to gain enough energy to escape

More information

Electromagnetic Radiation. Chapter 12: Phenomena. Chapter 12: Quantum Mechanics and Atomic Theory. Quantum Theory. Electromagnetic Radiation

Electromagnetic Radiation. Chapter 12: Phenomena. Chapter 12: Quantum Mechanics and Atomic Theory. Quantum Theory. Electromagnetic Radiation Chapter 12: Phenomena Phenomena: Different wavelengths of electromagnetic radiation were directed onto two different metal sample (see picture). Scientists then recorded if any particles were ejected and

More information

EE 5344 Introduction to MEMS CHAPTER 5 Radiation Sensors

EE 5344 Introduction to MEMS CHAPTER 5 Radiation Sensors EE 5344 Introduction to MEMS CHAPTER 5 Radiation Sensors 5. Radiation Microsensors Radiation µ-sensors convert incident radiant signals into standard electrical out put signals. Radiant Signals Classification

More information

Taking fingerprints of stars, galaxies, and interstellar gas clouds. Absorption and emission from atoms, ions, and molecules

Taking fingerprints of stars, galaxies, and interstellar gas clouds. Absorption and emission from atoms, ions, and molecules Taking fingerprints of stars, galaxies, and interstellar gas clouds Absorption and emission from atoms, ions, and molecules 1 Periodic Table of Elements The universe is mostly hydrogen H and helium He

More information