What is thedifferencebetweenanRtx
®
-1701 and anMXT
®
-1701 column?
Rtx
®
-1701 columns are made with polyimide-coated, fused silica tubing and are
deactivatedwith a nonpolar deactivation layer, resulting in the highest degree of tubing
inertness.MXT
®
-1701 columns aremade fromunbreakableSilcosteel
®
-treated stainless
steel. The Silcosteel
®
process bonds a thin, flexible layer to the stainless steel surface,
which offers efficiency and inertness comparable to fused silica tubing, with increased
durability. MXT
®
columns are caged in 4-inch diameter coils or smaller, and are ideal
for compact, portable, or process GCs. Both columns possess a maximum operating
temperature of 280°C.
Howdo I choose the right -1701 column formy application?
After you've decided whether you want an Rtx
®
-1701 column or an MXT
®
-1701
column, based on the answer to the question above, there are three main factors that
should be consideredwhen selecting a column: length, inside diameter (ID), and film
thickness.
Column length affects the total plate count, which in turn, affects separation. Typical
column lengths are 15, 30, 60, and 105meters.Most separations can be achievedwith
30-meter columns. However, if the sample contains very few compounds, a 15-meter
column might offer sufficient separation. Alternatively, a 60- or 105-meter column
might be required for samples containing large numbers of compounds.
Column ID affects both resolution and sample capacity. Typical column diameters
range from0.10mm ID to0.53mm ID. Smaller ID columns offer better separation, but
less sample capacity. 0.25mm and 0.32mm ID columns offer the best compromise
between separation and capacity.
Select film thickness based on the volatility range of the compounds in the sample.As
a general rule, use a film thickness of 1.0µm or greater for compounds with boiling
points below 200
o
C. For compoundswith boiling points higher than 200
o
C, use a film
thickness of less than 1.0µm.
For answers to specific applications questions regarding Rtx
®
-1701 columns, contact
Restek's Technical Service group, or your Restek representative.
What is an Integra-Guard
™
column?
Guard columns are commonly used to trap nonvolatile residues, to protect and prolong
the lifetime of the analytical column. However, formany analysts, the art of attaching a
guard column to the analytical column is amystery. Restek’s chemists have discovered
the solution to this mystery—the most reliable connection is no connection at all!An
Integra-Guard
™
column is acontinuous lengthof fused silica tubing, containingboth the
guard column and the analytical column. The guard column is tied separately from the
analytical column, using high-temperature string. Just imagine, guard columns
WITHOUTconnections - or leaks. Protectingyour capillarycolumnhasnever beeneasier!
?
At-a-Glance
Product
Information
fromRestek
Rtx
®
-1701/MXT
®
-1701 Columns
Column Selection
Made Easy
ezGC
™
software
: Restek has
Retention Index Libraries that
contain more than 3000 com-
pounds analyzed on the most
commonly used stationary
phases, in 10 different applica-
tionareas including: petroleum
hydrocarbons, solvents &
chemicals, flavors & fragranc-
es, FAMEs, pesticides, PCBs,
dioxins/ furans, semivolatiles,
volatiles, and drugs of abuse.
ezGC
™
software is available
from our chromatography
products catalog.
Consult theapplications section
(hundreds of chromatograms)
in
Restek’s chromatography
products catalog,
or on-line at
Contact
Restek’s Technical
Service
at
800-356-1688 or
814-353-1300, ext. 4
.We have
more than 25 trained chemists
with direct laboratory and ap-
plications experience, ready to
assist you in choosing the best
column.
Commonly Asked Questions
1
2
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