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

Size: px
Start display at page:

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

Transcription

1 2001 Spectrometers Instrument Machinery Movies from this presentation can be access at Chp20: 1 Optical Instruments

2 Instrument Components Components of various types of instruments for optical spectroscopy. Spectroscopic instruments consist of five components, (1) a stable source of radiation energy; (2) a wavelength selector that isolates a limited region of the spectrum for measurement; (3) one or more sample container; (4) a radiation detector, which converts radiant energy to a measurable electrical signal; and (5) a signal processing and readout unit i.e., computer. (a)arrangement for absorption measurement. The radiation of the selected wavelength is send through the sample and the transmitted radiation is measured by the detector/signal processor (b) Configuration for fluorescence measurement. Two wavelength selectors are needed to select the excitation and the emission wavelengths. The selected sources radiation is incident on the sample and the radiation emitted is measured, usually at right angles to avoid scattering. (c) Configuration for emission spectroscopy. A thermal sources of energy, such as flame or plasma, produces an analyte vapor that emits radiation isolated by the wavelength selector and converted to an electrical signal by the detector. 2 Optical Instruments

3 Varian Cary Spectrophotometer The Varian Cary 50 scanning UV-Vis instrument scans wavelength with the speed of comparable to diode array technology. The scan speed for the UV-Vis instrument can go up to 24,000 nm/min. with a resolution 1.65 nm bandwith. The lamp is a Xenon flash lamp technology with a range of 190nm to 1100 nm. Diffraction grading with blaze angle of 8.6 at 240nm. 3 Optical Instruments

4 Spectroscopic Sources Source must generate a beam of radiation that is sufficiently powerful to allow detection and measurements. A continuum source (spectral continuum) provides a broad distribution of wavelengths within a particular spectral range. A line sources emits a limited wavelength range. Spec20: Tungsten/halogen. Cary 50 & Fluorolog Spex3: Xenon Flash lamp 190nm 1100nm 4 Optical Instruments Other source of lamp include Low-pressure Mercury arc lamp for LC and Lasers.

5 Optical Materials The cell windows, lenses, mirrors and wavelength-selecting elements in an optical spectroscopic instrument must transmit radiation in the wavelength region being measured. Shown are wavelength range for several optical materials. Simple glass can be used in the visible region. Fused silica or quartz is needed for the UV region. Halide salts are often used in the IR region but have complication by being water soluble and also expensive. Spectrophotometer cuvettes, polystyrene with stopper have optical windows of nm 5 Optical Instruments

6 Sample Containers Sample containers, which are usually called cells or cuvettes must be made from material that is transparent in the spectral region of interest. 6 Optical Instruments

7 A monochromator is an optical device that can filter or transmit a mechanically selectable narrow band of wavelengths of light or other radiation chosen from a wider range of wavelengths available at the input. The monochromator can be tune by turning the crystal and allows selected wavelengths to be tuned or changed with great precision. Monochromator (Tuneable) 7 Optical Instruments

8 Monochromator A monochromator can use either the phenomenon of optical dispersion in a prism, or that of diffraction using a diffraction grating, to spatially separate the colors of light. It usually has a mechanism for directing the selected color to an exit slit. Usually the grating or the prism is used in a reflective mode. A reflective prism is made by making a right triangle prism (typically, half of an equilateral prism) with one side mirrored. The light enters through the hypotenuse face and is reflected back through it, being refracted twice at the same surface. The total refraction, and the total dispersion, is the same as would occur if an equilateral prism were used. 8 Optical Instruments

9 Wavelength Selector A device to restrict the radiation being measured to a narrow band is called a monochromator. The monochromator (a) grating monochromator; (b) prism monochromator. Filters may also be used to restrict the incident wavelength. These may either be interference or absorption filters. The scheme above shows the schematic cross section of an interference filter. How a grating works: 9 Optical Instruments

10 Resolution, Dispersion and Efficiency Resolution measures the ability to separate two closely spaced peaks. λ Δλ = nn, λ = wavelength, Δλ = difference between two wavelength (resolution) n = diffraction order (integer), N = number of grooves Dispersion measures the ability to separate wavelength difference by Dl through difference in angle, Df (radiants). Δφ Δλ = n dcosφ φ = reflection angle, d = distance between adjacent grooves Efficiency of grating determines what wavelength are allowed to pass. η = E o λ (grating) E λ (mirror) E λ o = irradiance at a particular wavelength diffraction E λ = irradiance of same wavelength reflected by mirror 10 Optical Instruments

11 Monochromator bandwidth Increasing monochromator bandwidth broadens the band and decreases the apparent absorbance. Note the narrower the bandwidth, the better the resolution. 11 Optical Instruments

12 Detector and Photoelectric Effect Spectroscopic information is detected in some manner and converted to a measurable quantity. The theory behind these detector is the photoelectric effect. 12 Optical Instruments

13 Detector (Transducer) Spectroscopic information is detected in some manner and converted to a measurable quantity. A detector is a device that indicates the existence of some physical phenomenon. A transducer is a type of detector that converts various types of chemical and physical quantities into electrical signals such as electrical charges, current, or voltage. 13 Optical Instruments

14 PhotoDiode Array Detector Photodiode arrays are example of multichannel instruments for UV/Vis absorption. These instruments are usually single-beam design with the the photodiode array placed in the focal plane of the spectrograph. The detector allow the measurement of an entire spectrum (900nm - 300nm) in 1 s. 14 Optical Instruments

15 Detector Charged Couple Devices: Stores photo-generated charge in a 2-dimensional array Infrared Detector Thermocouple: Junction between two different electrical conductors effect Ferroelectric material: material polarizes as function of temperature pyroelectric Photoconductive detector: semiconductor change conductivity with IR radiation Optical Sensor Optical Fiber: medium that carries light by total internal reflection Opotodes: optical electrodes, optic fibers with sensors tips Attenuated Total Reflectance: Sampling technique in which radiation enters the device through a set of mirrors. The sample is placed above a crystal with a high refraction index and absorbs part of the infrared light. 15 Optical Instruments

16 Photometry Configuration Instrument designs for UV/Vis photometers or spectrophotometers. (a)single-beam instrument: Light from filter or monochromator passes the sample or reference cell before the photodetector. (b) double-beam in space instrument: light from the filter or monochromator is split into two beams that simultaneously pass through the reference and sample cell before the matching photodetector (c) the double beam-in-line instrument: light is alternately sent through reference and sample cells before striking a single photodetector. 16 Optical Instruments

17 Double-Beam Spectrophotometer Instrument designs for UV/Vis photometers or spectrophotometers. Double-beam in space instrument: light from the filter or monochromator is split into two beams that simultaneously pass through the reference and sample cell before the matching photodetector 17 Optical Instruments

18 Spectrometers 18 Optical Instruments

19 UV photometers and spectrometers Spec20, spectrophotometer Usage: The instrument was introduced Bausch & Lomb in It is mostly used to determine the composition of solutions via the measurement of the absorption at specific wavelengths. It is commonly used to determine the concentration of substances in solution by measurement of absorbance at a particular wavelength and comparison to a standard of known concentration. A grating based spectrophotometer that uses a singlebeam 20 nm bandwidth in the visible light region. The instrument has has a mirrored scale graduated from 0-100% by 1% and from 0-infinite Optical Density (logarithmic scale in red). The wavelength scale is graduated from nm by 5 nm with numbered major divisions every 25 nm. The light sources is a Tungsten lamp with a grating monochromator and a photomultiplier detector. 19 Optical Instruments

20 UV photometers and spectrometers Spec20, spectrophotometer 20 Optical Instruments

21 Genesys 10S UV-Vis Spectrophotometer 21 Optical Instruments

22 Multichannel Instruments Photodiode arrays are example of multichannel instruments for UV/Vis absorption. These instruments are usually single-beam design with the the photodiode array placed in the focal plane of the spectrograph. The detector allow the measurement of an entire spectrum (900nm - 300nm) in 1 s. 22 Optical Instruments

23 Flame Atomic Absorption Spectroscopy Atomic absorption spectroscopy (AAS) determines the presence of metals in liquid samples. It also measures the concentrations of metals in the samples, with concentrations range in the low mg/l range (ppm). In their elemental form, metals will absorb ultraviolet light when they are excited by heat. Each metal has a characteristic wavelength that will be absorbed. The AAS instrument looks for a particular metal by focusing a beam of UV light at a specific wavelength through a flame and into a detector. The sample of interest is aspirated into the flame. If that metal is present in the sample, it will absorb some of the light, thus reducing its intensity. The instrument measures the change in intensity. A computer data system converts the change in intensity into an absorbance. More details in next chapter 23 Optical Instruments

24 Infrared Spectroscopy Infrared (IR) spectroscopy is a chemical analytical technique, which measures the infrared intensity versus wavelength (wavenumber) of light. Based upon the wavenumber, infrared light can be categorized as far infrared (4 ~ 400cm -1 ), mid infrared (400 ~ 4,000cm -1 ) and near infrared (4,000 ~ 14,000cm -1 ). Older IR instrument were dispersive double-beam designs. Fourier transformed infrared (FTIR) detect all the wavelength and are the standard type of equipment in today s lab. Most FTIR are single beam mode. The advantage of FTIR vs. dispersive spectrometers include better speed and sensitivity, better light-gathering power, more accurate wavelength calibration, simple mechanical design, and the virtual elimination of the problems of stray light and IR emission. 24 Optical Instruments

25 Fourier Transformed Infrared An interferometer utilizes a beam splitter to split the incoming infrared beam into two optical beams. One beam reflects off of a flat mirror which is fixed in place. Another beam reflects off of a flat mirror which travels a very short distance (typically a few millimeters) away from the beam splitter. The two beams reflect off of their respective mirrors and are recombined when they meet together at the beam splitter. The recombined signal results from the interfering with each other. Consequently, the resulting signal is called interferogram, which has every infrared frequency encoded into it. When the interferogram signal is transmitted through or reflected off of the sample surface, the specific frequencies of energy are adsorbed by the sample due to the excited vibration of function groups in molecules. The infrared signal after interaction with the sample is uniquely characteristic of the sample. The beam finally arrives at the detector and is measure by the detector. The detected interferogram can not be directly interpreted. It has to be decoded with a well-known mathematical technique in term of Fourier Transformation. The computer can perform the Fourier transformation calculation and present an infrared spectrum, which plots absorbance (or transmittance) versus wavenumber. 25 Optical Instruments

26 Fourier Transform Fourier analysis is a procedure in which a curve is decomposed into a sum of sine and cosine waves, called a Fourier series. A curve can be mathematically be decomposed by the series: y = a o sin(0wx) + b o cos(0wx) + a 1 sin(1wx) + b 1 cos(1wx) + ) + a 2 sin(2wx) + b 2 cos(2wx) +... Y = S [a n sin(nwx) + b n cos(nwx) ] 26 Optical Instruments

27 FT and S/N Signal-to-noise ratio (often abbreviated SNR or S/N) is an electrical engineering measurement, defined as the ratio of a signal power to the noise power corrupting the signal. A ratio higher than 1:1 indicates more signal than noise. Signal averaging is a signal processing technique applied in the time domain, intended to increase the strength of a small-amplitude signal that is buried in noise. By averaging trials, the signal-to-noise ratio is usually increased. 27 Optical Instruments

28 Signal Averaging Signal averaging is a signal processing technique applied in the time domain, intended to increase the strength of a signal relative to noise that is obscuring it. By averaging a set of replicate measurements, the signal-to-noise ratio, S/N, will be increased, ideally in proportion to the square root of the number of measurements. Ideally it is assumed that- Signal and noise are uncorrelated. Signal strength is constant in the replicate measurements. Noise is random, with a mean of zero. Under these assumptions let the signal strength is calculated by the following equation. S N = ns nσ 2 = n S σ Where, S= signal strength σ = standard deviation of a single measurment (or noise, N) n = number of signals added together 28 Optical Instruments

29 Summary Spectrometers, Electromagnetic Radiation and chemical information 29 Optical Instruments

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

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

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

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

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

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

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

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

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 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

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

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

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

Chemistry Instrumental Analysis Lecture 15. Chem 4631

Chemistry Instrumental Analysis Lecture 15. Chem 4631 Chemistry 4631 Instrumental Analysis Lecture 15 IR Instruments Types of Instrumentation Dispersive Spectrophotometers (gratings) Fourier transform spectrometers (interferometer) Single beam Double beam

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

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

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

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

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

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

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

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

C101-E111. Talk Letter. Vol.2 February 2009

C101-E111. Talk Letter. Vol.2 February 2009 C101-E111 UV Talk Letter Vol.2 February 2009 UV Talk Letter UV Talk Letter The Structure of a Spectrophotometer Vol.2 February 2009 1.The Measurement Principle Used by a Spectrophotometer The basic measurement

More information

levels. The signal is either absorbance vibrational and rotational energy levels or percent transmittance of the analyte

levels. The signal is either absorbance vibrational and rotational energy levels or percent transmittance of the analyte 1 In this chapter, absorption by molecules, rather than atoms, is considered. Absorption in the ultraviolet and visible regions occurs due to electronic transitions from the ground state to excited state.

More information

Introduction to Fourier Transform Infrared Spectroscopy

Introduction to Fourier Transform Infrared Spectroscopy molecular spectroscopy Introduction to Fourier Transform Infrared Spectroscopy Part of Thermo Fisher Scientific Introduction What is FT-IR? FT-IR stands for Fourier Transform InfraRed, the preferred method

More information

Analytical Technologies in Biotechnology Prof. Dr. Ashwani K Sharma Department of Biotechnology Indian Institute of Technology, Roorkee

Analytical Technologies in Biotechnology Prof. Dr. Ashwani K Sharma Department of Biotechnology Indian Institute of Technology, Roorkee Analytical Technologies in Biotechnology Prof. Dr. Ashwani K Sharma Department of Biotechnology Indian Institute of Technology, Roorkee Module - 6 Spectroscopic Techniques Lecture - 2 UV-Visible Spectroscopy

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

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

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

Chemistry 524--Final Exam--Keiderling Dec. 12, pm SES

Chemistry 524--Final Exam--Keiderling Dec. 12, pm SES Chemistry 524--Final Exam--Keiderling Dec. 12, 2002 --4-8 pm -- 238 SES Please answer all questions in the answer book provided. Calculators, rulers, pens and pencils are permitted plus one 8.5 x 11 sheet

More information

Introduction to FT-IR Spectroscopy

Introduction to FT-IR Spectroscopy Introduction to FT-IR Spectroscopy An FT-IR Spectrometer is an instrument which acquires broadband NIR to FIR spectra. Unlike a dispersive instrument, i.e. grating monochromator or spectrograph, an FT-IR

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

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

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

COLORIMETER AND LAMBERT S-BEER S LAW. Shingala vaishali Sandha prafulla Tiwari Kuldeep

COLORIMETER AND LAMBERT S-BEER S LAW. Shingala vaishali Sandha prafulla Tiwari Kuldeep COLORIMETER AND LAMBERT S-BEER S LAW Shingala vaishali Sandha prafulla Tiwari Kuldeep TOPIC What is colorimeter? Use of colorimeter. Component & It s function. Function of colorimeter. The principle of

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

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

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

Introduction to Fourier Transform Infrared Spectroscopy

Introduction to Fourier Transform Infrared Spectroscopy Introduction to Fourier Transform Infrared Spectroscopy Introduction What is FTIR? FTIR stands for Fourier transform infrared, the preferred method of infrared spectroscopy. In infrared spectroscopy, IR

More information

1901 Application of Spectrophotometry

1901 Application of Spectrophotometry 1901 Application of Spectrophotometry Chemical Analysis Problem: 1 Application of Spectroscopy Organic Compounds Organic compounds with single bonds absorb in the UV region because electrons from single

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

CEE 772: Instrumental Methods in Environmental Analysis

CEE 772: Instrumental Methods in Environmental Analysis Updated: 31 August 2014 Print version (Harris, Chapt. 1) (pp.1-20) CEE 772: Instrumental Methods in Environmental Analysis Lecture #3 Statistics: Detection Limits Spectroscopy: Beer s Law & Electronic

More information

FTIR Spectrometer. Basic Theory of Infrared Spectrometer. FTIR Spectrometer. FTIR Accessories

FTIR Spectrometer. Basic Theory of Infrared Spectrometer. FTIR Spectrometer. FTIR Accessories FTIR Spectrometer Basic Theory of Infrared Spectrometer FTIR Spectrometer FTIR Accessories What is Infrared? Infrared radiation lies between the visible and microwave portions of the electromagnetic spectrum.

More information

Chem 310 rd. 3 Homework Set Answers

Chem 310 rd. 3 Homework Set Answers -1- Chem 310 rd 3 Homework Set Answers 1. A double line labeled S 0 represents the _ground electronic_ state and the _ground vibrational_ state of a molecule in an excitation state diagram. Light absorption

More information

Real-time ppb CO 2 Impurity Detection by an Advanced FTIR- UVF System

Real-time ppb CO 2 Impurity Detection by an Advanced FTIR- UVF System Real-time ppb CO 2 Impurity Detection by an Advanced FTIR- UVF System Presented at the BevTech Conference, Albuquerque, NM 2018 by Charles M. Phillips Ph.D., Max Analytical Technologies Mark Taylor, Vice

More information

Chem Homework Set Answers

Chem Homework Set Answers Chem 310 th 4 Homework Set Answers 1. Cyclohexanone has a strong infrared absorption peak at a wavelength of 5.86 µm. (a) Convert the wavelength to wavenumber.!6!1 8* = 1/8 = (1/5.86 µm)(1 µm/10 m)(1 m/100

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

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

Absorption photometry

Absorption photometry The light Absorption photometry Szilvia Barkó University of Pécs, Faculty of Medicines, Dept. Biophysics February 2011 Transversal wave E Electromagnetic wave electric gradient vector wavelength The dual

More information

1 WHAT IS SPECTROSCOPY?

1 WHAT IS SPECTROSCOPY? 1 WHAT IS SPECTROSCOPY? 1.1 The Nature Of Electromagnetic Radiation Anyone who has been sunburnt will know that light packs a punch: in scientific terms, it contains considerable amounts of energy. All

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

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

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

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

Spectrophotometry. Dr. Shareef SHAIK ASST. PROFESSOR Pharmacology

Spectrophotometry. Dr. Shareef SHAIK ASST. PROFESSOR Pharmacology Spectrophotometry Dr. Shareef SHAIK ASST. PROFESSOR Pharmacology Content Introduction Beer-Lambert law Instrument Applications Introduction 3 Body fluids such as blood, csf and urine contain organic and

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

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

UNIT I COLORIMETER AND SPECTROPHOTOMETERS PART A

UNIT I COLORIMETER AND SPECTROPHOTOMETERS PART A UNIT I COLORIMETER AND SPECTROPHOTOMETERS PART A 1. List any four elements used in spectrophotometers. 1.Radiant source 2.wavelength selector 3.photodetector 4.sample 2. What is meant by flame emission

More information

Characterisation & Use of Array Spectrometers

Characterisation & Use of Array Spectrometers Characterisation & Use of Array Spectrometers Mike Shaw, Optical Technologies & Scientific Computing Team, National Physical Laboratory, Teddington Middlesex, UK 1 Overview Basic design and features of

More information

Some Topics in Optics

Some Topics in Optics Some Topics in Optics The HeNe LASER The index of refraction and dispersion Interference The Michelson Interferometer Diffraction Wavemeter Fabry-Pérot Etalon and Interferometer The Helium Neon LASER A

More information

AS 101: Day Lab #2 Summer Spectroscopy

AS 101: Day Lab #2 Summer Spectroscopy Spectroscopy Goals To see light dispersed into its constituent colors To study how temperature, light intensity, and light color are related To see spectral lines from different elements in emission and

More information

Problem Solving. radians. 180 radians Stars & Elementary Astrophysics: Introduction Press F1 for Help 41. f s. picture. equation.

Problem Solving. radians. 180 radians Stars & Elementary Astrophysics: Introduction Press F1 for Help 41. f s. picture. equation. Problem Solving picture θ f = 10 m s =1 cm equation rearrange numbers with units θ factors to change units s θ = = f sinθ fθ = s / cm 10 m f 1 m 100 cm check dimensions 1 3 π 180 radians = 10 60 arcmin

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

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

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

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

Vibrational Spectroscopies. C-874 University of Delaware

Vibrational Spectroscopies. C-874 University of Delaware Vibrational Spectroscopies C-874 University of Delaware Vibrational Spectroscopies..everything that living things do can be understood in terms of the jigglings and wigglings of atoms.. R. P. Feymann Vibrational

More information

Diagnósticos em Plasmas

Diagnósticos em Plasmas Tecnologia a Plasma para o Processamento de Materiais Diagnósticos em Plasmas Diagnósticos Ópticos João Santos Sousa, nº50901 Semestre Inverno 2004/2005 21 de Janeiro de 2005, 9h-10h, sala F8 Contents

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

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

Two-electron systems

Two-electron systems Two-electron systems Laboratory exercise for FYSC11 Instructor: Hampus Nilsson hampus.nilsson@astro.lu.se Lund Observatory Lund University September 12, 2016 Goal In this laboration we will make use of

More information

Clinical Chemistry (CHE221) Professor Hicks Week 1. Statistics Made Slightly Less Boring and Introduction to Spectrophotometry. Accuracy vs Precision

Clinical Chemistry (CHE221) Professor Hicks Week 1. Statistics Made Slightly Less Boring and Introduction to Spectrophotometry. Accuracy vs Precision Clinical Chemistry (CHE221) Professor Hicks Week 1 Statistics Made Slightly Less Boring and Introduction to Spectrophotometry 3 Accuracy vs Precision Precision is the consistency of a measurement made

More information

Lecture PowerPoints. Chapter 24 Physics: Principles with Applications, 7 th edition Giancoli

Lecture PowerPoints. Chapter 24 Physics: Principles with Applications, 7 th edition Giancoli Lecture PowerPoints Chapter 24 Physics: Principles with Applications, 7 th edition Giancoli This work is protected by United States copyright laws and is provided solely for the use of instructors in teaching

More information

PAPER No. 12: ORGANIC SPECTROSCOPY MODULE No. 4: Basic principles and Instrumentation for IR spectroscopy

PAPER No. 12: ORGANIC SPECTROSCOPY MODULE No. 4: Basic principles and Instrumentation for IR spectroscopy Subject Chemistry Paper No and Title Module No and Title Module Tag Paper 12: Organic Spectroscopy Module 4: Basic principles and Instrumentation for IR spectroscopy CHE_P12_M4_e-Text TABLE OF CONTENTS

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

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

MOLEBIO LAB #4: Using a Spectrophotometer

MOLEBIO LAB #4: Using a Spectrophotometer Introduction: Spectrophotometry MOLEBIO LAB #4: Using a Spectrophotometer Many kinds of molecules interact with or absorb specific types of radiant energy in a predictable fashion. For example, when while

More information

m m lighter 'atom' dominates 2 INFRARED SPECTROSCOPY All modes of vibrations are not IR active.

m m lighter 'atom' dominates 2 INFRARED SPECTROSCOPY All modes of vibrations are not IR active. INFRARED SPECTROSCOPY Infrared spectroscopy probes the interaction of infrared radiation with covalent bonds in molecules. Absorption of IR radiation results in the transitions between vibrational energy

More information

Atomic Emission Spectroscopy

Atomic Emission Spectroscopy Atomic Emission Spectroscopy Ahmad Aqel Ifseisi Assistant Professor of Analytical Chemistry College of Science, Department of Chemistry King Saud University P.O. Box 2455 Riyadh 11451 Saudi Arabia Building:

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

SPECTROPHOTOMETRY AND SPECTROMETRY - CONCEPT AND APPLICATIONS

SPECTROPHOTOMETRY AND SPECTROMETRY - CONCEPT AND APPLICATIONS SPECTROPHOTOMETRY AND SPECTROMETRY - CONCEPT AND APPLICATIONS Renjini A 1, Dani Dileep 2 1 Assistant Professor, Department of ECE, Rajadhani Institute of Engineering and Technology, Kerala, India 2 PG

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

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

Fourier transform infrared spectroscopy (FTIR) is a method used to obtain an infrared

Fourier transform infrared spectroscopy (FTIR) is a method used to obtain an infrared Fourier Transform Infrared Spectroscopy: Low Density Polyethylene, High Density Polyethylene, Polypropylene and Polystyrene Eman Mousa Alhajji North Carolina State University Department of Materials Science

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

Application of IR Raman Spectroscopy

Application of IR Raman Spectroscopy Application of IR Raman Spectroscopy 3 IR regions Structure and Functional Group Absorption IR Reflection IR Photoacoustic IR IR Emission Micro 10-1 Mid-IR Mid-IR absorption Samples Placed in cell (salt)

More information

Chapter 24 Photonics Question 1 Question 2 Question 3 Question 4 Question 5

Chapter 24 Photonics Question 1 Question 2 Question 3 Question 4 Question 5 Chapter 24 Photonics Data throughout this chapter: e = 1.6 10 19 C; h = 6.63 10 34 Js (or 4.14 10 15 ev s); m e = 9.1 10 31 kg; c = 3.0 10 8 m s 1 Question 1 Visible light has a range of photons with wavelengths

More information

Basics of UV-Visible Spectroscopy *

Basics of UV-Visible Spectroscopy * OpenStax-CNX module: m34525 1 Basics of UV-Visible Spectroscopy * Brittany L. Oliva-Chatelain Andrew R. Barron This work is produced by OpenStax-CNX and licensed under the Creative Commons Attribution

More information

n ( λ ) is observed. Further, the bandgap of the ZnTe semiconductor is

n ( λ ) is observed. Further, the bandgap of the ZnTe semiconductor is Optical Spectroscopy Lennon O Naraigh, 0000 Date of Submission: 0 th May 004 Abstract: This experiment is an exercise in the principles and practice of optical spectroscopy. The continuous emission spectrum

More information

Lecture 7: Optical Spectroscopy. Astrophysical Spectroscopy. Broadband Filters. Fabry-Perot Filters. Interference Filters. Prism Spectrograph

Lecture 7: Optical Spectroscopy. Astrophysical Spectroscopy. Broadband Filters. Fabry-Perot Filters. Interference Filters. Prism Spectrograph Lecture 7: Optical Spectroscopy Outline 1 Astrophysical Spectroscopy 2 Broadband Filters 3 Fabry-Perot Filters 4 Interference Filters 5 Prism Spectrograph 6 Grating Spectrograph 7 Fourier Transform Spectrometer

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

Thermal And Near infrared Sensor for carbon Observation (TANSO) On board the Greenhouse gases Observing SATellite (GOSAT) Research Announcement

Thermal And Near infrared Sensor for carbon Observation (TANSO) On board the Greenhouse gases Observing SATellite (GOSAT) Research Announcement Thermal And Near infrared Sensor for carbon Observation (TANSO) On board the Greenhouse gases Observing SATellite (GOSAT) Research Announcement Appendix A Outlines of GOSAT and TANSO Sensor GOSAT (Greenhouse

More information

Vibrational Spectroscopy of Molecules on Surfaces

Vibrational Spectroscopy of Molecules on Surfaces Vibrational Spectroscopy of Molecules on Surfaces Edited by John T. Yates, Jr. University of Pittsburgh Pittsburgh, Pennsylvania and Theodore E. Madey National Bureau of Standards Gaithersburg, Maryland

More information

two slits and 5 slits

two slits and 5 slits Electronic Spectroscopy 2015January19 1 1. UV-vis spectrometer 1.1. Grating spectrometer 1.2. Single slit: 1.2.1. I diffracted intensity at relative to un-diffracted beam 1.2.2. I - intensity of light

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

Physics 30: Chapter 5 Exam Wave Nature of Light

Physics 30: Chapter 5 Exam Wave Nature of Light Physics 30: Chapter 5 Exam Wave Nature of Light Name: Date: Mark: /33 Numeric Response. Place your answers to the numeric response questions, with units, in the blanks at the side of the page. (1 mark

More information

IR Spectrography - Absorption. Raman Spectrography - Scattering. n 0 n M - Raman n 0 - Rayleigh

IR Spectrography - Absorption. Raman Spectrography - Scattering. n 0 n M - Raman n 0 - Rayleigh RAMAN SPECTROSCOPY Scattering Mid-IR and NIR require absorption of radiation from a ground level to an excited state, requires matching of radiation from source with difference in energy states. Raman

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

Fourier Transform IR Spectroscopy

Fourier Transform IR Spectroscopy Fourier Transform IR Spectroscopy Absorption peaks in an infrared absorption spectrum arise from molecular vibrations Absorbed energy causes molecular motions which create a net change in the dipole moment.

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