General Catalogue Chemistry - BECO Internacional LTDA.

In gas chromatography a mixture of substances
is heated inside the injector until all components
are present in a gaseous state. A uniform gas
flow (the mobile phase) drives the mixture
through a helical tube (column). The tube is
packed with a solid carrier material such as
Al 2 O 3 loaded with a liquid, such as paraffin,
which has a high boiling point (the stationary
phase). The components in the gas mixture will
pass throughthe column at varying rates, depending
on the carrier material or the solubility in the
stationary phase. Evidence of the presence of the
components is given with the aid of a sensor
which responds to particular characteristics in
the gases. Often the thermal conductivity properties
of gases are used as a differentiating characteristic
(heat conductivity sensor). The sensor
registers the thermal conductivity of the gas and
outputs an electrical signal which is either
applied to a chart recorder or processed by a PC.
At a controlled temperature and a constant carrier
gas flow rate, the dwell time (retention time)
in the column can be used to identify the substance
(qualitative analysis). The surface area
below the peaks is a measure of the quantity
for the individual components (quantitative
analysis).
Equipment list
Gas chromatography
Quantity Description Cat. No.
1 Demonstration gas chromatograph, basic unit . . . . . . . . .665 490
1 DC 550 column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .665 533
1 Gas sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .665 495
1 Controllable aeration pump . . . . . . . . . . . . . . . . . . . . . . . .666 482
1 Silicon tubing, 1 m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .604 432
1 CPS power supply, 24 V AC/3 A . . . . . . . . . . . . . . . . . . . .667 824
1 Panel frame, C50, two-level . . . . . . . . . . . . . . . . . . . . . . . .666 425
>
For more columns:
see page 54
Demonstration gas chromatograph CPS 490
This equipment system is an inexpensive and
reliable demonstration model for gas chromatographic
separations at room temperature; the
system has been developed for introducing the
method of gas chromatography with simple
means.
Equipment list
chromatography
Gas chromatography
The separating columns can also be used in the
gas chromatograph > 665 531
Gas chromatography, alternative with heat conductivity detector
Quantity Description Cat. No.
1 Demonstration gas chromatograph, basic unit . . . . . . . . .665 490
1 DC 550 column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .665 533
1 Heat conductivity detector . . . . . . . . . . . . . . . . . . . . . . . . .665 496
1 CPS holder for gas cartridge . . . . . . . . . . . . . . . . . . . . . . .665 492
1 Disposable cartridge N 2 O . . . . . . . . . . . . . . . . . . . . . . . . .665 491
or . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1 Disposable cartridge CO 2 . . . . . . . . . . . . . . . . . . . . . . . . .665 493
1 Silicon tubing, 1 m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .604 432
1 CPS power supply, 24 V AC/3 A . . . . . . . . . . . . . . . . . . . .667 824
1 Panel frame, C50, two-level . . . . . . . . . . . . . . . . . . . . . . . .666 425
as carrier gas also helium can be used,
e. g. from a Minican gas can
1 MINICAN gas can: Helium . . . . . . . . . . . . . . . . . . . . . . . . .660 984
1 Fine regulating valve MINICAN for gas cans . . . . . . . . . . .660 980
1 Fine regulating valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .660 980
1 Silicon tubing, 1 m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .604 432
1 CPS Holder, for pressurized gas cans . . . . . . . . . . . . . . . .666 458
LEYBOLD DIDACTIC · GENERAL CATALOGUE CHEMISTRY
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