Spectroscopy
22 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the study of the interaction between matter and electromagnetic radiation?

  • Spectroscopy (correct)
  • Crystallization
  • Electrophoresis
  • Chromatography

    • What is the basis of spectroscopy?

  • Measurement of the temperature of the sample
  • Interaction between electromagnetic radiation and atoms or chromophoric groups in the molecules (correct)
  • Interaction between electromagnetic radiation and molecules only
  • Measuring the pH of the sample

    • What is the characteristic of radiation in spectroscopy?

  • It only behaves as a beam of particles
  • It only behaves as an electromagnetic wave
  • It has no characteristics
  • It behaves as both an electromagnetic wave and a beam of particles (correct)

    • What is the type of spectroscopy that involves the measurement of the radiation absorbed by atoms?

    <p>Atomic Absorption Spectroscopy</p> Signup and view all the answers

    What is the type of spectroscopy that involves the measurement of the radiation emitted by atoms?

    <p>Atomic Emission Spectroscopy</p> Signup and view all the answers

    What is the type of spectroscopy that involves the measurement of the radiation absorbed by molecules?

    <p>UV-Vis Spectroscopy</p> Signup and view all the answers

    What is the main difference between a fluorimeter and a UV-Vis spectrophotometer?

    <p>Two monochromators are used in a fluorimeter, one for excitation and one for emission</p> Signup and view all the answers

    What is the type of radiation absorbed by nuclei in NMR spectrometry?

    <p>Electromagnetic radiation in the radio frequency region</p> Signup and view all the answers

    What is the purpose of the strong external magnetic field in NMR spectroscopy?

    <p>To orient the nuclear spin in a specific way</p> Signup and view all the answers

    Which of the following is NOT a type of spectroscopy?

    <p>Mass spectrometry</p> Signup and view all the answers

    What is the purpose of one-dimensional 13C NMR spectroscopy?

    <p>To determine the chemical structure of biomolecules</p> Signup and view all the answers

    What is the function of flavoproteins in spectrofluorimetry?

    <p>To give fluorescence that can be measured at 525 nm after excitation at 345 nm</p> Signup and view all the answers

    What is the wavelength range of the fluorescence spectrum for Tyr?

    <p>300 nm (maximum)</p> Signup and view all the answers

    What is the relationship between the energy difference and microwave radiation in NMR spectroscopy?

    <p>The energy difference corresponds to microwave radiation</p> Signup and view all the answers

    What is the primary function of the nebulizer gas in atomic absorption spectroscopy?

    <p>To create a high-velocity gas stream across the capillary</p> Signup and view all the answers

    What is the significance of the cut-off value in UV-Vis spectroscopy?

    <p>It determines the wavelength below which the solvent absorption is greater than 0.3</p> Signup and view all the answers

    What is the primary difference between single-beam and double-beam UV-Vis spectrophotometers?

    <p>The presence of a beam splitting arrangement</p> Signup and view all the answers

    What is the purpose of the burner in atomic absorption spectroscopy?

    <p>To atomize the sample</p> Signup and view all the answers

    What is the importance of the droplet-size distribution of the aerosol in atomic absorption spectroscopy?

    <p>It affects the subsequent states of the aerosol</p> Signup and view all the answers

    What is the primary function of the cuvette in UV-Vis spectroscopy?

    <p>To hold the sample and reference solutions</p> Signup and view all the answers

    What is the significance of the surface tension of the solution in atomic absorption spectroscopy?

    <p>It affects the droplet-size distribution of the aerosol</p> Signup and view all the answers

    What is the primary advantage of double-beam UV-Vis spectrophotometers over single-beam spectrophotometers?

    <p>They enable a simultaneous comparison of the absorption by both the sample and reference cuvettes</p> Signup and view all the answers

    Study Notes

    Spectroscopy

    • Study of the interaction between matter and electromagnetic radiation
    • Method of analysis used in experimental biochemistry, natural product chemistry, and for feed and food analyses

    Atomic Spectroscopy

    • Involves the measurement of the absorption and emission of radiation by atoms and molecules
    • Interpretation of the absorption and emission of radiation can gain information about the structure or concentration of the species interacting with the radiation

    UV-Vis Spectroscopy

    • Instruments:
      • Single-beam
      • Double-beam
      • Multibeam
    • Double-beam spectrophotometers contain a beam splitting arrangement, enabling simultaneous comparison of absorption by sample and reference cuvettes
    • Solvents and cuvettes:
      • UV-Vis spectroscopy is performed with analytes in solution, which may be limited by the availability of suitable solvents
      • Organic solvents required to dissolve biomolecules have simple structures and only tend to absorb light toward the short wavelength end of the UV spectrum
      • Solvent absorption is often said to have a cut-off value, which is the wavelength below which the solvent absorption is greater than 0.3 in a cuvette with a 1 cm path-length
      • Cuvettes must be made of special optical transparent material

    Fluorimetry

    • In protein, Tyr and Trp are native major fluorescent groups
    • Fluorescence spectrum for Tyr has its maximum around 300 nm, which is about 20 nm higher than the corresponding absorption spectrum
    • NADH and NADPH are fluorescent compounds, allowing many redox-enzymes that utilize these coenzymes to be analyzed by spectrofluorimetry
    • Flavoproteins also give fluorescence, which can be measured at 525 nm after excitation at 345 nm
    • Fluorimeter requires two monochromators, one for excitation and one for emission

    Nuclear Magnetic Resonance (NMR)

    • NMR spectrometry is a special form of absorption spectrometry in which nuclei of certain isotopes in a magnetic field absorb electromagnetic radiation in the radio frequency region
    • NMR spectrum is a plot of the frequencies of the absorption peaks versus peak intensities
    • Minute magnet property of nuclei is an essential characteristic for NMR spectroscopy studies (e.g. 1H, 3H, 13C, 15N, and 31P)
    • Analysis basis:
      • When a sample is placed in a strong external magnetic field, the different orientations of the nuclear spin will have different energies
      • The energy difference between two energy states corresponds to microwave radiation, which is sufficient to flip the nuclei from one energy state to another
    • NMR spectroscopy is a powerful technique for structural identification of biomolecules

    Mass Spectrometry (MS)

    • Mass spectroscopy is not a spectroscopic technique, as it does not involve electromagnetic radiation and quantum principles
    • The first stage involves nebulization, in which an analyte solution is drawn into the burner via a narrow capillary as a result of the high-velocity gas stream across the tip of the capillary
    • The droplet-size distribution of the aerosol is affected by the physical properties of the solution, e.g. viscosity, density, and surface tension, flow rates of the nebulizer gas and sample solution

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Spectroscopy PDF

    Description

    This quiz covers the study of the interaction between matter and electromagnetic radiation, including various types of spectroscopy such as atomic, UV-Vis, colorimetry, fluorimetry, NMR, mass spectrometry, and infrared spectroscopy.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser