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GC COLUMNS |
CAPILLARY COLUMNS
Select ing a GC Column
Selection of Capillary Column Summary
Selecting a capillary column for an analysis can be done by following these basic steps:
1)Choose the proper phase for the compounds being chromatographed
a. Review the application section of this catalog or
for similar compound list.
b. Call Restek’s experienced technical support team (800-356-1688, ext. 4)
or e-mail us at:
•
(in the USA)
•
(international)
• or contact your Restek representative.
2)Select column ID, film thickness, and length
a. Base choice on:
• Injection technique (split, splitless, cool on-column, etc.)
• Detector type (is low flow required?)
• Amount of analyte being injected onto column (sample capacity)
3)Set optimum parameters for your analysis
a. Optimize column flow (mL/min.)
b. Choose appropriate carrier gas (hydrogen, helium, or nitrogen)
c. Optimize oven temperature program
ID
df (µm)
temp. limits
0.25mm 1.40
-40 to 240/260°C
0.32mm 1.80
-40 to 240/260°C
0.45mm 2.55
-40 to 240/260°C
0.53mm 3.00
-40 to 240/260°C
All Restek columns have published minimum and maximum operating temperatures
that establish the working range for the stationary phase. Note that these ranges vary
with the thickness of the coating.
Rtx®-VMS (fused silica)
Many phases list 2 maximum operating temperatures.
The first temperature is the maximum isothermal
operating temperature. This is the temperature to
which the columns are guaranteed to meet the mini-
mum bleed specification (i.e., lowest bleed level). The
second temperature is the maximum temperature-
programmed operating temperature, the temperature
to which the column can be heated for short periods
of time (i.e., during a temperature-programmed
analysis). If only one temperature is listed, it is both
the isothermal and the maximum temperature.
The minimum operating temperature defines the
lowest usable temperature before the stationary
phase solidifies. Operating the column below the
minimum temperature will not harm the phase, but
poor peak shape and other chromatography problems
may occur.
What Are the Operating Temperatures for My Column?
need
more
help?
• Call 800-356-1688 or
814-353-1300, ext. 4,
or your Restek
representative.
• Visit
• Email (U.S.):
Email (outside U.S.):
Chromatogram
Search Tool
Search by compound name, synonym,
CAS # or keyword
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TelNo : 03 9762 2034 . . . in AUSTRALIA
Mar 2011
