Thursday, January 27, 2011

The Muddiest Mud of Ch. 13

Although chapter 13 in Smith explains the function and technique of a Mass Spectrometer, the book does not contain a picture of an actual Mass Spectrometer. So the muddiest point of the chapter concerned what an actual Mass Spectrometer looked like. As instructed in Smith, a mass spectrometer vaporizes a sample and bombards it by a beam of electrons to form an unstable radical cation, which then decomposes to smaller fragment. Then the positively charged ions are passed through a negatively charged plates and then go through a curved analyzer tube in a magnetic field. This magnetic field causes the ions to deflect by different amounts due to their ratio of mass to charge, which is then plotted by a computer on a mass spectrum of m/z.

JEOL, a global scientific Analytical Instrument company, produces a few different types of Mass Spectrometers. One model JEOL produces is the AccuTOF DART(Image 1). DART stands for direct analysis in real time. This machine allows for analysis of solid, liquid, and/or gaseous sample at atmospheric pressure and ground potential by simply placing the sample between the DART and the mass spec. By reporting the exact mass measurements together with precise isotopic abundances can rapidly identify unknown compounds by their elemental compositions.


                                                  (Image 1: AccuTOF DART)
Sources: 

1. Janice Smith,Organic chemistry. 3rd. New York City: McGraw-Hill Companies, 2008. pg 463
2. JEOL. AccuTOF DART. 2011 http://www.jeol.com/PRODUCTS/AnalyticalInstruments/MassSpectrometers/AccuTOFDART/tabid/141/Default.aspx
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4 comments:

  1. Ashley MilesJanuary 28, 2011 at 5:21 PM

    Wow! This a really good blog entry. I never even thought about what an actual Mass Spectrometer looked like, but this is really neat! I love how you added a picture in your blog and cited your sources correctly at the bottom of your blog. I also think its great that you didn't just show us a picture, but you actually explained what it did so we could put it all together. Great Job! :-)

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  2. John HarboldJanuary 31, 2011 at 1:37 PM

    Very interesting and informative blog entry that I really enjoyed. I like how the picture was used and then you went into detail about how the Mass Spectrometer is used. I never fully understood how the Mass Spectrometer was used so thank you for the explanation. Thanks again for a great blog and look forward to those in the future.

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  3. Dr. MJanuary 31, 2011 at 7:04 PM

    Kevin,

    There is a researcher at Eastern KY University by the name of Darrin Smith who uses the DART-MS technique. I spoke with him about it (and the possibility of visiting CU) while at the KAS meeting this past fall. Perhaps you could look him up and extend an invitation on behalf of your interested Organic Chemistry class...?

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  4. LauraJanuary 31, 2011 at 8:59 PM

    On a personal note: Way to go, Kevin. Your blog made mine look like a crummy Organic Chemistry assignment. =)

    Time to be professional, I did not realize there wasn't a picture of a MS in the book. After reading your blog you have "tweeked" my interest. I can honestly say I would enjoy having the oppurtunity to see a real mass spec. and how it works. So on behalf of your organic chemistry class, I too think you should contact Mr. Smith. Have a wonderful day.

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