Process behavior in extraction and separation; color reaction, chemical qualitative experiment

Calculation of unsaturation: elemental analysis; isotope abundance ratio method, HR-MS (high resolution mass spectrometry): FT-MS (Fourier transform ion cyclotron resonance mass spectrometer), TOF-MS (time of flight mass spectrometry), Obitrap-MS

Determination of the molecular formula: CxHyOm(NH)n: Ω=x-y/2 1. For example, C8H13O2N3: C8H10O2(NH)3, Ω=8-10/2 1=4

Qualitative identification of functional groups

UV (determine the conjugated system), IR (determine the functional group), NMR (determine the molecular structure and relative configuration), MS (determine the molecular weight and molecular formula, and analyze partial structures based on fragment characteristics)

1D, 2D-NMR Chemical degradation, derivative preparation

CD, ORD X-ray diffraction artificial chiral synthesis

The absorption spectrum caused by the electron transition from the ground state to the excited state (π → π *, n → π *) in the ultraviolet and visible light region (200~700nm)

Structural identification of compounds containing conjugated double bonds, α,β-unsaturated carbonyl groups, and aromatic compounds

Specific absorption spectrum characteristics → Judgment of skeleton type, such as: flavonoids, coumarins, and anthraquinones

Regular changes in spectra before and after adding diagnostic reagents → Inference of substituents, such as flavonoids and coumarins

Absorption spectrum in the infrared region (4000~625 cm-1) caused by chemical bond vibration

Characteristic frequency area: 4000~1500 cm-1: Determine the type of functional group Fingerprint area: 1500~600 cm-1: conformation, configuration, substitution pattern, etc.

Accurate MS analysis enables molecular formula analysis Mass spectral fragments of fingerprint characteristics can be characterized by database technology Controlled ionization technology (MS/MS) for structural analysis of unknowns Isotope peak information can provide information on the elemental composition of molecules Hyphenated technology can be used for mixture analysis to improve work efficiency Provide information on molecular functional groups Excellent detection limits

source of ion

Quality detector

resolution

Electron impact mass spectrometryEI

chemical dissociation CI

Electrospray ionization ESI

Atmospheric Pressure Chemical Ionization APCI

Comparison of ESI-MS and APCI-MS

Quadrupole mass analyzer

Time of Flight (TOF) detector

FT-MS