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GMI has complete core competency with
the entire Hewlett Packard and Agilent mass spectrometry product
line:
Agilent
HP 5973 Mass
Spectrometer
Agilent
HP 5972 Mass
Spectrometer
Hewlett Packard
5971 Mass
Spectrometer
Hewlett Packard
5970 Mass
Spectrometer
Count on GMI for all of your GC and GC-MS
analytical instrumentation such as Agilent 5973 series models . Because we work carefully with you
before the sale to determine the best hardware fit for your application
with sensitivity to budget we
don't list prices on our web.
We are happy to
provide a pricing proposal based on your specific needs. Unlike
most resellers we can provide
installation and training. Most of GMI's customers come to the
GMI training facility and are trained on their instrument prior to
it being installed at their lab!
GMI will customize the hardware to match
your specific application / separation / analysis.
We can also offer proprietary options
such as inert ion sources greatly enhancing sensitivity with some
analytes and reducing cost of ownership.
$
Interested in buying a GC MS or
learning more about our GCMS options?
Please
click here
to fill out our contact page or contact our knowledgeable sales
force at
763-712-8717 / 800-745-2710 for more information or quotation
Basic principle of operation:
Mass spectrometers use the
difference in mass-to-charge ratio (m/e) of ionized atoms or molecules
to separate them from each other. Mass spectrometry is therefore
useful for quantitation of atoms or molecules and also for determining
chemical and structural information about molecules. Molecules have
distinctive fragmentation patterns that provide structural information
to identify structural components.
The general operation of a
mass spectrometer is:
-
create gas-phase ions
-
separate the ions in space
or time based on their mass-to-charge ratio
-
measure the quantity of
ions of each mass-to-charge ratio
The ion separation power of a
mass spectrometer is described by the resolution, which is defined as:
R = m /  m,
where m is the ion mass and
m is the difference in
mass between two resolvable peaks in a mass spectrum. E.g., a mass
spectrometer with a resolution of 1000 can resolve an ion with a m/e
of 100.0 from an ion with an m/e of 100.1.
Instrumentation
In general a mass
spectrometer consists of an ion source, a mass-selective analyzer, and
an ion detector. Since mass spectrometers create and manipulate
gas-phase ions, they operate in a high-vacuum system. The
magnetic-sector, quadrupole, and time-of-flight designs also require
extraction and acceleration ion optics to transfer ions from the
source region into the mass analyzer. The details of mass analyzer
designs are discussed in the individual documents listed below. Basic
descriptions of sample introduction/ionization and ion detection are
discussed in separate documents on ionization methods and ion
detectors, respectively.
A typical
configuration consists of a gas chromatograph (GC) with a
quadrupole mass spectrometer (MS) as a detector
(Alternatively, an ion trap detector (or TOF time of flight) may be
employed). In the normal mode of operation, a sample consisting
of a mixture of organic compounds which are volatile at a temperature
of 275 degrees C is introduced to the head of the column with a
syringe. Helium serves as a carrier gas to move the sample through the
column. During passage through the column (a fused silica capillary
with a wall coating of a thermally stable, non-volatile liquid), the
mixture is separated into individual components. As each component
issues from the column, it is introduced to the mass spectrometer
where a mass spectrum for that material is obtained and stored in a
computer. The spectrum is interpreted, either manually or by a
computer search, to identify the compound. |
