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What is the study of the interaction between matter and electromagnetic radiation?
What is the basis of spectroscopy?
What is the characteristic of radiation in spectroscopy?
What is the type of spectroscopy that involves the measurement of the radiation absorbed by atoms?
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What is the type of spectroscopy that involves the measurement of the radiation emitted by atoms?
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What is the type of spectroscopy that involves the measurement of the radiation absorbed by molecules?
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What is the main difference between a fluorimeter and a UV-Vis spectrophotometer?
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What is the type of radiation absorbed by nuclei in NMR spectrometry?
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What is the purpose of the strong external magnetic field in NMR spectroscopy?
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Which of the following is NOT a type of spectroscopy?
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What is the purpose of one-dimensional 13C NMR spectroscopy?
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What is the function of flavoproteins in spectrofluorimetry?
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What is the wavelength range of the fluorescence spectrum for Tyr?
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What is the relationship between the energy difference and microwave radiation in NMR spectroscopy?
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What is the primary function of the nebulizer gas in atomic absorption spectroscopy?
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What is the significance of the cut-off value in UV-Vis spectroscopy?
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What is the primary difference between single-beam and double-beam UV-Vis spectrophotometers?
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What is the purpose of the burner in atomic absorption spectroscopy?
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What is the importance of the droplet-size distribution of the aerosol in atomic absorption spectroscopy?
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What is the primary function of the cuvette in UV-Vis spectroscopy?
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What is the significance of the surface tension of the solution in atomic absorption spectroscopy?
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What is the primary advantage of double-beam UV-Vis spectrophotometers over single-beam spectrophotometers?
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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
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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.
