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