RestekCapillaryColumn InstallationGuide, Section II
length (m)
hydrogen
helium
15
0.63min./TCD
1.25min.
30
1.25min.
2.5min.
60
2.5min.
5.0min.
105
4.38min.
8.75min.
* Nitrogen is not recommended as a carrier gas for most capillary columns because inadequate resolution and longer
analysis times result.
IV. Confirming Installation Integrity
We highly recommend using the dead volume peak shape test and the solvent peak
shape test to confirm installation integrity.
DeadVolumePeakShape Test
Examine the dead volume peak. A sharp, narrow peak that shows no sign of tailing
indicates an unobstructed sample pathway and correct installation (
FigureH
). Tailing
peaks indicate improper column installation, gross contamination of the splitter sleeve,
a cracked splitter sleeve, improper sweeping of the column end bymake-up gas, a
crushed column end, or a column that has degraded. The cause of a tailing non-retained
peakmust be corrected before using the column analytically.
FigureH
: Dead volume peak shape test
Tailing peaks indicate
improper installation
Symmetrical Peaks
indicate
proper installation
Solvent PeakShape Test
The solvent peak shape test is an additional indicator of proper column installation in
the inlet and outlet. Since compounds used to set the dead volume are usually gases at
room temperature (methane), they are not extremely
sensitive indicators of system or installation problems.
A 1µl injection of a liquid solvent, such asmethylene
chloride, expands to over 500µl of gas volume, making
any potential installation or system problem readily
apparent. A tailing solvent peak is a sensitive indicator
of broken, undeactivated, or contaminated inlet
sleeves. Tailing solvents also indicate problems with
inadequatemake-up gas or improper column insertion
into the detector.
To perform the test, inject 1µl of a solvent in the split
mode at 40°C isothermal and examine the peak shape
(
Figure I
). The solvent peak should be symmetrical
and showminimal tailing. If tailing appears, suspect an
installation or system problem. The cause of a tailing
