Mass Spectrospcopy



Consequently, the ratio of mass to charge abbreviated as m/e becomes the equivalence of the molecular weight of the component. In this technique, the analysis of the data generated involves the re-assembling of the components and then moving backwards to find the original sample molecule (Klein 673). The fundamental guidelines of mass spectroscopy date back to as early as the 1890s when J.J Thomson was able to ascertain the mass to charge ratio of the electron. Additionally, Wien who illustrated that the magnetic deflection of anode (negatively charged terminal) rays were positively charged is a founding figure in mass spectroscopy. These men were honored with Nobel Prizes for their experiments in this technique. In later years, probably in 1912, J.J. Thomson again was in the limelight yet with another study on Neon atom. In his study, he subjected the Neon-20 atom to mass spectrometry and found a variant atom, Neon-22. This suggested that neon in fact was an isotopic element. The earliest form of a mass spectrometry machine was built in 1918 by A.J. Dempster. It was until the mid 1960s that the method of mass spectrometry came into proper and common use because the machines were reliable and affordable (Pavia 443). With the advancement in ionization techniques of high molecular weight substances between 1980s and 1990s, this analytic procedure has grown immensely. Introduction of affordable instruments that provide high resolution has enabled researchers in all fields to conduct in depth analysis of various molecules ranging from oligonucleotides, and other biological compounds. Mass spectrometry traverses all fields and has been of significant value in drug development, and drug discovery. Within the health sector, this technique has been vital in the testing of blood and urine samples for detection of compounds termed as markers in specific conditions. Environmentally, this technique has been relied on for monitoring water and air quality as well as testing of energy reserves (Pavia 449). The procedural breakdown of mass spectroscopy begins when a very low concentration of sample molecule is allowed to pass through an ionization chamber. The chamber is usually maintained at very high levels of vacuum. Within this chamber, the sample substance is subjected to a high energy electron beam that essentially produces negatively charged ions. As a result of this bombardment, the constituent molecules in the sample substance fragment. The positively charged ions that are produced are the passed on to an analyzing tube. The path which these cations flow within the tube is curved as result of a magnetic field. Positively charged particles, cations which have the lowest rates of motion implying a low mass, are deflected most by the strong magnetic field. These molecules subsequently collide with the walls of the analyzer. On the other hand, high molecular weight components which tend to have high momentum are not deflected by the magnetic forces and as such do not undergo collision. Of importance are the ions which possess proper mass to charge proportion (Klein 687). Notably, these ions flow through the path of the analyzer, leave the path through an outlet and run into the collector. This collision with the collector produces an electric current which is stepped up