While Mass Spectroscopy is not covered in our texts, other mass/density dependent technologies including X-ray Spectroscopy, Gamma Spectroscopy,

1
While Mass Spectroscopy is not covered in our
texts, other mass/density dependent technologies
including X-ray Spectroscopy, Gamma Spectroscopy,
Ultrasound Analysis are covered in Guy
ffytche, An Introduction to The Principles of
Medical Imaging, Imperial College Press, 2000,
Chapters 4,5 7. Other coverage is also found
in Shung, Chapters 1, X-ray, 2, Ultrasound, in
Shung, Smith, Tsui, Principles of Medical
Imaging, Academic Press, 1992.
2

• This method uses one of several means to
• vaporize a sample
• ionize /or fragment it
• introduce it into a low vacuum space
• sort the fragment ions based on charge to mass
  ratio, m/z
• detect the ions impinging on a charge or
  photosensitive device, e.g., film or photodiodes

Note that heavy isotopes yield higher m/z for a
given compound, yielding multiple MS peaks with
heights proportional to the abundance of the
isotopes.
3
Animations of MS ( other techniques) http//spid
er-dev.pharmacy.strath.ac.uk/mscpharmanal/sample.h
tm
4
(No Transcript)
5
(No Transcript)
6
MS Basics in Denmark http//130.237.33.129/klab/
Kvantfysik_5A1450/var_labbar.htm
University of Calgary MS Basics http//www.chem.u
calgary.ca/courses/351/Carey/Ch13/ch13-ms.html
MS Basics http//web.njit.edu/hsieh/ene669/gc_ms
.html
http//www.astbury.leeds.ac.uk/facil/MStut/mstutor
ial.htm
http//www.udel.edu/chem/koh/chem333docs/MSlect1pp
.pdf
http//www.files.chem.vt.edu/chem-ed/crossref/ac-m
ass-spec.html
MS Basics PPTs, College of Charleston, Dept. of
Chemistry http//www.cofc.edu/chem/organic/Slide
s/MS1/index.htm http//www.cofc.edu/chem/organic/
Slides/MS2/index.htm http//www.cofc.edu/chem/org
anic/ Slides/MS3/index.htm
Mass Spectrometry Bulletin http//www.rsc.org/Pub
lishing/CurrentAwareness/msb/index.asp
7
MS methods differ with respect to complexity of
the molecules that can be evaluated with
respect to the sensitivity of the methods. The
more energy introduced in volatilizing ionizing
the sample the more likely molecules, especially
large ones, will fragment. While smaller
molecules may be introduced directly into the MS
ionization chamber as pure compounds or as
simplified mixtures resulting from the use of gas
chromatographs upstream from the ionization
chamber, this is not possible for most high
polymers. The parent peak from the ion formed
when the entire molecule looses only 1 electron
provides molecular mass information. It is often
vital to the analysis to find this peak which may
only form under relatively gentle conditions.
8
Macromolecules may be introduced into the
ionization chamber as pure materials or as
simplified mixtures filtered through upstream
high performance or liquid chromatographs. They
may also be lifted from surfaces directly used
to examine surface compositions. The surface
itself may be modified to assist volatilization
ionizatin by absorbing much of the thermal energy
of the ionization source (laser, microwave, )
/or by capturing electrons from the
macromolecules to generate ions secondarily.
MALDI, matrix assisted laser desorption
ionization, uses easily volatilized ionized
organics such as cinnamic acid, gentisic acid,
sinapinic acid to improve movement of
macromolecules such as peptides from a surface to
the ion stream. Nucleic acids may be examined
similarly.
9
Calibration for accuracy requires examination of
molecules with known parent peak m/z known
fragmentation patterns. For more complex
molecular mixtures it also requires inclusion of
internal calibration molecules that provide
reference peaks from which to mark m/z positions,
e.g., digestive enzyme fragmentation peaks in
protein digestion experiments. Note that MS
methods may not have uniform sensitivity across
the entire m/z range of interest thus, multiple
calibration or reference peaks may be needed.
Fragmentation is also frequently run as a series
of pulses each of which generate a set of data
noise peaks. Digital accumulation of pulse
results accentuate true peaks enhance
sensitivity by increasing precision
specificity.
10
Introduction to MS, Scripps http//masspec.scripp
s.edu/information/index.html
Introduction to MALDI
http//www.psrc.usm.edu/mauritz/maldi.html
Protein MS Tools
http//prospector.ucsf.edu/
http//winter.group.shef.ac.uk/chemputer/isotopes.
html
11
http//www-methods.ch.cam.ac.uk/meth/ms/theory/sec
tor.html
12
http//www.york.ac.uk/depts/biol/tf/analbio_ms.htm
13
Example of MS/MS Schematic
In MS/MS the initially ionized sample is passed
through a 2nd ionization stage to further
fragment initially formed ions yielding more
structural detail.
http//www.fastcomtec.com/fwww/tofmas/wrecmas.htm
14
Use of MALDI-TOF 1st followed by MS/MS in
proteomics http//bmbus6.leeds.ac.uk/www/presenta
tions/MassSpec/index.htm
MS vs MS/MS Analysis http//www-helix.inrialpes.f
r/article386.html
http//www.ionspec.com/Applications/applications_i
nfo.htm
15
www.chm.bris.ac.uk/pt/diamond/image/mwmbms.gif
16
www-methods.ch.cam.ac.uk/.../ theory/iontrap.html
17
http//www.ansto.gov.au/ansto/environment1/ams/ind
ex.html
18
http//www.elementalanalysis.com/icp/
19
Pesticide Analysis http//www.epa.gov/nerlesd1/ch
emistry/org-anal/reports/regmsf/regmsf.htm
Mass Spectroscopy Applications
Biological Mass Spectrometry http//www.amolf.nl
/research/biological_mass_spectrometry/main.html
BioMS at UMass http//www.umass.edu/karbon13/inde
x.htm
Proteomics MS http//www.mrc-dunn.cam.ac.uk/re
search/proteomes.html
DNA Sequencing http//www.cs.sunysb.edu/skiena/6
48/presentations/massspec/dna.html
Epigenotyping using MS http//www.epigenome.org/i
ndex.php?pageepigenotyping1
Archaeometry Laboratory U. of MO Research
Reactor http//www.missouri.edu/rjse10/home.htm
20
Fragmantation patterns of organic
ions http//poohbah.cem.msu.edu/courses/CEM924JA/
Fan_Shuan2/organic/index.htm
Analytical Microscopy http//www.nrel.gov/measur
ements/analytical.html
21
Crystallography Heavy Atom Substitution http//c
ns.csb.yale.edu/v1.0/tutorial/text.html
TEM Staining http//www.lehigh.edu/ols0/tem/sta
ining.html http//www.aecom.yu.edu/iag/samples/fil
es/TEM.html http//www.cimc.cornell.edu/Pages/Gall
ery.htm http//www.pegacat.com/cbetts/phd/index.ht
ml
X-ray, Ultrasound, MRI Contrast Media