The Applications of Mass Spectrometry
Mass spectrometry (MS), especially combined with chromatography and computer technologies, has been widely used in organic chemistry, biochemistry, drug metabolism, clinical, toxicology, determination of pesticides, environmental protection, petroleum chemistry, geochemistry, food chemistry, chemical plants, cosmic chemistry and chemical defense and other fields.
Ion detection by mass spectrometry can be used for qualitative analysis, for example, in biological research and pharmacological drugs, and its metabolites can be integrated on the gas chromatogram, the retention time and mass fragments can identify the details of drugs and metabolites; it also can be used for quantitative analysis, with a test compound isomers as stable isotope internal standard, more accurate results can be expected.
In inorganic chemistry and nuclear chemistry, many low-volatile substances can be determined by a high-frequency spark source mass spectrometry. This approach requires a pure sample ionization electrode. If the sample shows in powder form, it can be mixed up with nickel powder to make electrode. This method is particularly valuable for the analysis of high-purity substances in alloys, minerals, atomic energy, semiconductor material, and other processes, which might detect the content of one billionth of impurities.
Using a long-life radioisotopes decay time to determine the presence of objects in the archeology and geography is quite significant. For example, a radioactive mineral has radioactive uranium and decay-lead, the decay rate of uranium-238 and uranium-235 is known, and the isotopes relative abundance of decay of uranium and lead is measured by the MS, then we can estimate the generated era of the mineral.
In terms of using MS, mass spectrometer is necessary. There are many different types of instruments with different application features, but in general, 300C vaporized sample can be analyzed with priority to GC-MS since GC-MS uses EI source and can get more mass spectra. If it is not vaporized at 300C, you need to use LC-MS analysis to get molecular weight and structure information if it is tandem mass spectrometry. If the sample is biological macromolecules, we will use LC-MS and MALDI-TOF analysis. For protein samples, the amino acid sequence can be also determined. The resolution of the mass spectrometer is an important technical indicator. High-resolution mass spectrometer can provide compound formula, which is very important for the structure determination.
Mass spectrometry has certain requirements for samples, for example, GC-MS analysis should use organic solution…