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Ultraviolet absorption spectroscopy, fluorescence spectroscopy, infrared absorption spectroscopy... These are the methods of instrument analysis that we often use in the laboratory. Today, the small editor from the abbreviation, analysis principles, spectral means, the information provided for you to briefly comb.
1. Ultraviolet Absorption Spectrum
Abbreviation: UV;
Analysis Principles: Absorption of ultraviolet light energy, causing the leap of electron energy levels in molecules;
spectrograph: relative absorption of light energy with changes in the wavelength of absorbed light; information provided by
: position, intensity and shape of absorption peaks, providing information on different electron structures in molecules
China
.
2. Fluorescence Spectroscopy
Abbreviation: FS;
Analysis Principle: After being stimulated by electromagnetic radiation, from the
lowest single-line excitation state to a single-line baseline state, emitting
fluorescence;
3. Infrared Absorption Spectroscopy
Abbreviation: IR;
Analysis Principles: Absorption of infrared light energy, causing vibration of molecules with even-polar moment changes, rotational energy stage leap;
spectrograph: relative transmission light energy varies with transmission light frequency;
provides information: peak position, intensity and shape, providing functional groups or chemical key characteristic vibration frequency.
4. Raman Spectroscopy
Abbreviation: Ram;
Analysis Principles: After absorbing light energy, it causes molecular vibrations with changes in polarization rate, resulting in Raman scattering,
spectrograms are represented by scattering light energy with Raman displacement, and
provides information: the position, intensity and shape of peaks, providing characteristic vibration frequencies of functional clusters or chemical bonds.
5. MRI spectrometography:
: NMR;
Analysis principle: In the external magnetic field, the nucleus with the nuclear magnetic moment absorbs radio frequency energy to produce the
leap of the nuclear spin energy level;
6. Electron flux resonance spectrometography
abbreviation: ESR;
analysis principle: in the external magnetic field, the molecule does not have a pair of electrons to absorb radio frequency energy, resulting in electron spin energy stage leap;
spectral representing method: absorption of light energy or split energy varies with the strength of the magnetic field;
provides information: spectral line position, strength, number of fissures and ultra-fine split constant, providing unconsted electron density, molecular bond properties and geometric configuration information.
7. Mass spectrometography
Abbreviation: MS;
Analysis Principles: Molecules are bombarded by electrons in a vacuum to form ions, separated by different m/e by electromagnetic field;
spectral representation: the relative peak of ions in the form of rod charts varies with m/e;
provides information on the mass and relative peaks of molecular and fragmented ions, providing information on molecular weight, element composition and structure.
8. Gas chromatography
Abbreviation: GC;
Analysis Principle: The parts in the sample are
separated between the flow phase and the fixed phase due to different distribution coefficients
;
9. Anti-gas chromatography
Abbreviation: IGC;
Analysis Principles: The change in probe molecular retention depends on the interaction force
between it and the polymer sample as a fixed phase;
10. Lysing gas chromatography
Abbreviation: PGC;
analysis principle: polymer materials in a certain conditions of instant lysing, can obtain fragments with certain characteristics;
spectral representing method: the concentration of post-column outflow with the reserved value changes,
provides information: the fingerprint or characteristic fragment peak of the spectral map, the chemical structure and geometry of the character of the polymer.
11. Gel Chromatography
Abbreviation: GPC;
Analysis Principle: When a sample passes through a gel column, it is separated according to the fluid mechanics volume of the molecule, and the large molecules flow out first; the
spectral represents the change of the concentration of the post-column outflow with the reserved value; and the information provided by
: the average molecular weight of the polymer and its distribution.
12. Thermal weight method
Abbreviation: TG;
Analysis Principle: In temperature control environment, sample weight varies with temperature or time;
spectral represents: sample weight fraction with temperature or time curve;
provides information: the steep drop of the curve is the sample weight loss zone, the platform area is the thermal stability zone of the sample.
13. Thermal Difference Analysis
Abbreviation: DTA;
Analysis Principle: Samples and comparators are in the same temperature control environment, due to the difference in thermal conductivity between the two temperature differences
, record
temperature changes with ambient temperature or time;
14. Thermal analysis of the spread scanning volume
Abbreviation: DSC;
analysis principle: samples and comparants in the same temperature control environment, recording the temperature difference of zero, the required energy with the ambient temperature or time changes;
spectral means: heat or its rate of change with the ambient temperature or time of the curve; information provided by
: provides information on polymer thermal transition temperature and various thermal effects
15. static thermal-force analysis
Abbreviation: TMA;
analysis principles: the deformation of samples under constant force changes with temperature or time;
spectral means: sample deformation with temperature or time curve;
provides information: thermal transition temperature and dynamic state.
16. Dynamic Thermal-Force Analysis
Abbreviation: DMA;
Analysis Principles: The deformation of a sample under the action of periodic changes in external forces varies with temperature; the
spectral represents the mod or tan δ curve with temperature; and the information provided by
: thermal transition temperature modulation and tan δ.
17. Transmission electron microscopy
: TEM;
Analysis principle: scattering, absorption, interference and
diffraction occur when high-energy electron beam penetrates the sample, which causes the formation of lining in the phase plane, showing the image
;
18. Scanning electron microscopy
abbreviation: SEM;
Analysis principle: using electronic technology to detect the action of high-energy electron beams and samples to
produce secondary electrons, backscale electrons, absorption of electrons,
X-rays and other magnified spectra;
。