Tandem mass spectrometry refers to mass spectrometry methods that use mass spectrometry for mass separation. It also has several names such as mass spectrometry, multistage mass spectrometry, two-dimensional mass spectrometry, and sequential mass spectrometry.
1. Inducing the fragmentation of the molecular ion generated by the first-stage mass spectrometry is beneficial to study the relationship between the product ion and the parent ion, and then give the structural information of the molecular ion.
2. Extract useful data from mass spectrometry with serious interference, greatly improve the selectivity of mass spectrometry detection, so that trace substances in mixtures can be determined.
Combination of tandem mass spectrometers:
1. Magnetic analyzer – electrostatic analyzer – magnetic analyzer
2. Electrostatic analyzer – magnetic analyzer – electrostatic analyzer
3. Triple quadrupole mass filter mass spectrometer
4. Hybrid tandem mass spectrometer, such as MA-ESA-Q-Q. There are two ways to realize tandem mass spectrometry: spatial tandem and temporal tandem. The role of spatial tandem mass spectrometry is illustrated by MA-ESA-Q-Q. The mechanism is as follows: first use MA for mass separation, sieve out a certain ion first, perform the first collision activation between MA and ESA, and high-energy ions generate first-order daughter ions; A certain ion is first sieved out of the ion. After deceleration, it undergoes a second collision activation in the first-level Q to generate a low-energy collision-induced decomposition product (second-level product ion), and the second-level product ion then passes through the second-level Q. Analysis, since high- and low-energy collision-induced decomposition products are simultaneously detected in this system, comprehensive ion information can be obtained. The ion trap is a time tandem mass spectrometer, in which mass selection, ion activation, and mass analysis are performed, and can be repeated many times.