Mass Spectrometry (MS) was said to be discovered by J.J. Thomson and his student F.W. Ashton in 1887. They conducted the first known measurement of mass-to-charge ratio of “corpuscles”- known today as electrons (1). Since its origin, many others have refined the process of mass spectroscopy in order to make the process easier to conduct and to easier understand the results. Mass Spectrometry is useful as an analytical tool in order to determine the structure of various molecules. By depending on both electric and magnetic fields, the mass of the particles is analyzed and can be compared to previously known molecules for further categorization.
In order to further understand how MS works, it is important to know the components consisting of an ion source, an ionizer (which converts the sample into ions to be detected throughout the MS process), a mass analyzer, and a detector. A MS sample can be taken from any form, such as solid, liquid, or gas, and is bombarded with electrons in order to ionize it. Through this process, the sample breaks down into charged fragments which are then separated through their mass-to-charge ratio due to the magnetic and electric forces forced upon the ions from the sample (1). This process of separation of ions is based on Newton’s second law of motion, stating that the forces of an object is equal to the mass multiplied by the acceleration (2). The analyzer then is used to record the abundance of each type of ion and allows for the chemical composition of the sample to be determined.
The techniques for ionization can be different depending on the sample. For gases or vapors, electron or chemical ionization can be used for optimal results. When working with liquids or solid biological samples, electrospray ionization and matrix-assisted laser desorption/ionization (MALDI) can be used. From a biochemical perspective, the MALDI technique is often used to determine the structure of proteins, which delves further into the world of proteomics (3).
Taken together, MS has allowed for much further insight into understanding the composition of various samples which is whyy it is considered a valuable tool in any laboratory.
- Griffiths, W J, et al. “Electrospray and Tandem Mass Spectrometry in Biochemistry.” Advances in Pediatrics., U.S. National Library of Medicine, 1 May 2001, www.ncbi.nlm.nih.gov/pmc/articles/PMC1221768/.
- “Newton’s Second Law of Motion .” NASA, NASA, www.grc.nasa.gov/www/k-12/airplane/newton2.html.
- Karas, M., et al. “Matrix-Assisted Ultraviolet Laser Desorption of Non-Volatile Compounds.” Egyptian Journal of Medical Human Genetics, Elsevier, 5 Dec. 2001, http://www.sciencedirect.com/science/article/pii/0168117687870416?via%3Dihub.