Mass+Spectrometry


 * __What is Mass Spectrometry? __**

This is a special technique used in Cell Biology to identify compounds on the basis of their precise mass-to-charge ratio. It is also a powerful tool used for identifying proteins and sequencing polypeptides. A visual can been seen in Figure 1


 * Figure 1**. Cartoon diagram of mass spectrometry. source: [|antoine.frostburg.edu]

__**Purpose: **__ The main purpose of this technique is to separate the compound's ions based on their mass to charge ratio. The information it can provide are clues to determine the precise mass of intact proteins and peptides of unknown proteins. A more detailed flow chart is shown in Figure 2.
 * Figure 2**. Flow Chart of Mass Spectrometry. Source: [|www.lamondlab.com]

__**Origin: **__

This technique originated from an experiment on the existence and properties of canal rays, also known as positive ions. This experiment occurred around the late 1890's. Toward the end of WWI, scientists demonstrated the existence of several isotopes of non-radioactive elements. Electrostatic and magnetic fields were used to separate isotope ions by their masses. In the late 1930's, mass spectrometry became an established technique. The key individuals who began the original protocol of mass spectrometry are Joseph John Thomson and Francis William Aston.


 * __Applications of Mass Spectrometry: __**

In the article, "Femtomole sequencing of proteins... [1]," another form of mass spectrometry is introduced. This form known as Electrospray mass spectrometry is a very sensitive technique for sequencing protein and short peptides. Some important information that this article reveals is that nano-electrospray mass spectrometry was used in another study to figure out what factors suppress the formation of new blood vessels. Also, amino acid sequence data can now be obtained by mass spectrometry with small quantities of gel-isolated proteins. This technique is about 10-100 times more sensitive but it faster and uses less purification and manipulation steps.

In the article, "Determination of chloramphenicol residues in rainbow trouts... [2]," the importance is that researchers are trying to study the identification and quantification of chloramphenicol (CAP) residues in 40 samples of rainbow trout. This was done by using gas chromatography-mass spectrometry (GCMS) technique which is a screening procedure. This also reveals that systems of identification points are adopted to define the number of ions and their corresponding ratios using the mass spectrometry techniques. Using the GCMS technique, the rainbow trout were considered suspect to having CAP if all of the selected ions (mlz225, mlz208 and mlz242) were present on the chromatographic peak and if there is a relative abundance of these ions (Santos, Barbosa, and et al 249-56) . Throughout the experiment, 15 of the 40 trout were considered to having CAP. From this study, the GCMS method allows detection and confirmation of CAP, at trace levels, in rainbow trout muscle.

In the article, "Rapid Screening of Polar Compounds... [3]," the main importance was that researchers were studying the polar propolis fractions by using high-temperature high-resolution gas chromatography (HTHR-GC) and HTHR-GC mass spectrometry (Pereira, Norsell, and et al 5226-30) <span style="font-family: 'Comic Sans MS',cursive; line-height: 1.5;">. The main purpose was to establish the applicability of HTHR-GC as an analytical method to study propolis. What this article revealed was the carbohydrates, phenolic acid and high molecular weight compounds could be identified by these techniques.

__**<span style="font-family: 'Comic Sans MS',cursive;">References: **__

<span style="font-family: 'Comic Sans MS',cursive;">[1] Wilm, Matthias, Andrej Shevchenko, Tony Houthaeve, et al. "Femtomole sequencing of proteins from polyacrylamide gels by nano-electrospray mass spectrometry." 379. (1996): 466-469. Web. 24 Mar. 2013. <http://proteome.gs.washington.edu/classes/Genome490/papers/Wilm_et_al_Nature_1996.pdf>.

<span style="font-family: 'Comic Sans MS',cursive;">[2] Santos, Lucia, Jorge Barbosa, et al. "Determination of chloramphenicol residues in rainbow trouts by gas chromatography–mass spectometry and liquid chromatography–tandem mass spectometry." 529.1-2 (2005): 249-56. Web. 24 Mar. 2013. <http://gp9bz7mp8a.search.serialssolutions.com.ezproxy.oswego.edu:2048/?genre=article&issn=00032670&title=Analytica Chimica Acta&volume=529&issue=1-2&date=20050124&atitle=Determination of chloramphenicol residues in rainbow trouts by gas chromatography-mass spectometry and liquid chromatography-tandem mass spectometry&spage=249&pages=249-256&sid=EBSCO:Biological Abstracts&aulast=Santos, La&pid=BACD200500132210>.

<span style="font-family: 'Comic Sans MS',cursive;">[3] Pereira, A.S., M. Norsell, et al. "Rapid Screening of Polar Compounds in Brazilian Propolis by High-Temperature High-Resolution Gas Chromatography−Mass Spectrometry." 48.11 (2000): 5226-30. Web. 24 Mar. 2013. <http://gp9bz7mp8a.search.serialssolutions.com.ezproxy.oswego.edu:2048/?genre=article&issn=00218561&title=Journal of Agricultural and Food Chemistry&volume=48&issue=11&date=20001101&atitle=Rapid screening of polar compounds in Brazilian propolis by high-temperature high-resolution gas chromatography-mass spectrometry&spage=5226&pages=5226-5230&sid=EBSCO:Biological Abstracts&aulast=Pereira, A. S.&pid=BACD200100067111>.

<span style="font-family: 'Comic Sans MS',cursive;">[4] Alberts, Bruce, Alexander Johnson, et al. Molecular Biology of The Cell. 5th ed. New York: Garland Science, Taylor & Francis Group, 2008. Print.