1 quadrupole mass spectrometer
Mass spectrometer/spectrograph/spectroscope
At present, the quadrupole mass filter is still the most widely used. The selective reaction monitoring (SRM) mode of three-stage quadrupole mass spectrometer is suitable for routine and Qualcomm bioanalysis. The improvement of quadrupole technology and the strong stability of RF greatly improve the resolution of mass spectrometry, and the width of resolution mass number reaches 0. 1Da, which improves the selectivity of analytical compounds. With the improvement of collision cell in three-stage quadrupole mass spectrometry, high-voltage linear acceleration collision cell appeared, which improved the ion transport ability, reduced the interference between substances and greatly improved the analytical ability of multi-component biological compounds. Among all mass spectrometers, quadrupole mass spectrometer has the best accuracy and precision in quantitative analysis.
Quadrupole ion trap mass spectrometer
Three-dimensional quadrupole ion trap is widely used to clarify the structure of compounds. Related innovations mainly include the development of matrix-assisted laser desorption ionization source, atmospheric pressure matrix-assisted laser desorption ionization source, infrared multiphoton photodissociation technology, and the analysis of basic addition ions and metal coordination products by ion trap. In recent years, breakthroughs have been made in the fabrication of linear two-dimensional ion traps. Like the three-dimensional ion trap, this linear two-dimensional ion trap can be used for multi-level mass spectrometry analysis of compounds, in addition, it can accumulate more ions and improve the detection sensitivity. After being connected with the ionization source of the linear accelerated collision cell, the sensitivity can be greatly improved, the interference of small molecular weight fragments can be avoided, and a cleaner and more beautiful chromatographic peak can be obtained.
Time of flight mass spectrometer
With the appearance of matrix-assisted laser desorption ionization technology and the development of computer, time-of-flight mass spectrometer developed rapidly in the 1990s. At present, the resolution of the best time-of-flight mass spectrometer can reach 20,000Da, and the measured molecular mass has high accuracy. Time-of-flight mass spectrometer has largely replaced the high-resolution dual-focus magnetic fan analyzer, but it can not effectively use the selected ion monitoring mode for analysis. Double focusing mass spectrometer is still mainly used for the analysis of selective ion monitoring mode in high resolution mass spectrometry. In order to analyze the secondary mass spectra of compounds with high resolution mass spectrometry, people try to combine time-of-flight mass spectrometry with other mass spectrometry. At present, a new generation of quadrupole time-of-flight mass spectrometry system (AB SCIEX TripleTOF 5600+) with breakthrough technology is widely used to ensure that the system can obtain high-precision mass spectrometry data and quantitative detection limit.
4 Fourier transform ion cyclotron vibration analyzer
Over the years, Fourier transform-cyclotron resonance mass spectrometry (FT-ICR-MS) has become an effective means for the basic research of gas-phase ion-molecule reactions. After mass spectrometry is connected with ESI ion source, it is widely used in the study of biological macromolecules, which can give full play to its advantages of high resolution and high accuracy. Based on the quadrupole excitation of ions in the Fourier transform ion cyclotron, the mass spectrometer can selectively accumulate ions of complex compounds with non-valence bonds, enabling it to analyze biomacromolecules with very large molecular weight, such as Escherichia coli bacteriophage T4DNA with molecular weight as high as 108Da, which has become an important milestone in the development of the mass spectrometer. The mass spectrometer can eliminate the interference of other ions by radio frequency pulses, selectively capture the target ions into the ion cyclotron, and can also perform multi-stage mass spectrometry analysis. At present, many new ion cleavage methods have been applied to Fourier transform ion cyclotron resonance mass spectrometer, such as collision-induced cleavage, laser-induced photodissociation or infrared multiphoton photodissociation, surface-induced cleavage, blackbody infrared radiation cleavage, electron capture cleavage and so on. The analytical performance of the mass spectrometer is further improved.
In addition to the common interface technology and mass spectrometer described above, there are other products coming out continuously. In recent ten years, people have shifted their research focus to developing strong technologies suitable for a certain analytical field and accelerating the commercialization of products. In a word, the development of LC-MS analysis technology depends on the synchronous development of LC-MS interface technology and mass spectrometer technology. By connecting the liquid chromatography with the mass spectrometer through an appropriate interface, a liquid-mass spectrometer with special analytical performance will be obtained. In addition, connecting the mass spectrometer and mass spectrometer in series through the interface can make up for the shortcomings of various mass spectrometers and achieve the effect of learning from each other's strong points and improving synergistically.