What isanMXT®column?
MXT® columns aremade from stainless steel tubing that hashad
the internal surface treated with our exclusive Siltek® surface
treatment. The Siltek® layermakes the surface as inert as deacti-
vated fused silica. The unique Siltek® process enables us to offer
MXT® columns in awide range of internal diameters, including
0.18mm, 0.25mm, 0.32mm, and 0.53mm. Because the Siltek®
layer permeates the stainless steel surface, rather than simply
coating it, the layer is exceptionally flexible, so the tubing can be
coiled to very small diameters. The standard coil diameter for
MXT® columns is 4.5 inches. The minimum coil diameter for
0.53mm ID columns is 2.5 inches, and theminimum coil diam-
eter for 0.25mm ID columns is 1.5 inches.
The unique properties of the Siltek® treated surface enable us to treat the tubing with a wide variety of
polymer phases.Themany choices ofMXT® columns include:
113
GCCOLUMNS |
METAL (MXT®) CAPILLARYCOLUMNS
MXT® Columns Overview
• MXT®-1
• MXT®-5
• MXT®-20
• MXT®-35
• MXT®-50
• MXT®-65
• MXT®-1301
• MXT®-1701
• MXT®-200
• MXT®-WAX
• MXT®-65TG
• MXT®-Biodiesel TG
• MXT®-2887
• MXT®-1HT SimDist
• MXT®-1 SimDist
• MXT®-500 SimDist
• MXT®-502.2
• MXT®-Volatiles
• MXT®-624
• Guard tubing
CompareMXT®columnsand fusedsilicacolumns:
• Metal tubing allowsMXT® columns tobeused tohigher temperatures (430 °C) than fused silica columns
(standard rating is 360 °C).This is because the polyimide resin that encases the fused silica becomes brittle
over time at high temperatures.MXT® columns donot become brittle.
• Inertness ofMXT® columns and fused silica columns is similar, due to theunique properties of the Siltek®
surface treatment inMXT® columns.
• Metal columns canbe coiledunder 4.5 incheswithout breaking, ideal for small instruments.
• Coating efficiency (plates/meter) ofMXT® columns is similar to that of fused silica.
• MXT® columnswill not breakunder stress, and they canbe coiled to small diameters.
MXT®columnsareyourbestchoice for:
• Situations inwhich the potential for columnbreakage is high:
• field instruments
• processGC
• GCswith small ovens, such as portable instruments, requiring tightly coiled columns.
• High temperature chromatography. Siltek®deactivated stainless steel tubing canwithstand temperatures
exceeding 430 °C; the only limitation tooven temperature is the polymer itself.
CustomMXT®columns
We are able to supply 0.18, 0.25, 0.28, 0.32, and 0.53mm ID columns with the phases listed above inmany
different configurations. If you do not see the column youneed listed in the following pages, call us or your
Restek representative, andwewill behappy tohelp.
MXT®-BiodieselTGcolumnsareundamagedbyhigh thermal cycles compared to
high-temperature fused silicacolumnswhichbreakdownunder the sameconditions.
100 temperature cycles to430 °C totaling500minutes atmaximum temperature.
MXT®-BiodieselTGcolumnsare
undamagedbyhigh thermal cycles.
HT fused silicacolumns, labeledas stable
to430 °C, showpittingandbreakdown.
MXT
ideal for
high-temperature
analyses
also
available
MetalPLOT
columns!
Seepages108-110.
Website :
E-mail :
TelNo : 03 9762 2034 . . . inAUSTRALIA
Mar 2011
