Rtx
®
-CLPesticides
Capillary Columns
At-a-Glance
Product
Information
fromRestek
800-356-1688
814-353-1300
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What are theRtx
®
-CLPesticides/Rtx
®
-CLPesticides2 columns?
The Rtx
®
-CLPesticides/Rtx
®
-CLPesticides2 columns are fused silica capillary
columns coatedwith a unique stationary phase specifically designed to provide
the best separation of chlorinated pesticides. The Rtx
®
-CLPesticides/Rtx
®
-
CLPesticides2 columns are used in parallel for simultaneous quantitation and
confirmation by gas chromatography/electron capture detection (GC/ECD). The
Rtx
®
-CLPesticides/Rtx
®
-CLPesticides2columnsare intermediatepolaritycolumns.
Feature
Benefit
Unique phase
Exceptional inertness
High thermal stability
Baseline resolution of pesticides in fast
analysis time; better resolution than other
available phases; improved qualitative and
quantitative reliability.
No on-column breakdown of sensitive
pesticides; reducesGC and column
maintenance.
Permits column bake-out to remove high-
boiling contaminants; reduces contaminant
interferences with target analytes; decreases
ECD bleed; reduces systemmaintenance.
Features&Benefits
Optimizing theanalysis of pesticides using the
Rtx
®
-CLPesticides columnpair
In theenvironmental industry, analyticalmethods for chlorinatedpesticidesoften
are themost challenging toperform.Analysts strugglewith linearity, breakdown,
and lengthy calibrations; as well as column bleed, column reactivity, and poor
separation.Not onlydo the labs keep trackof resolution requirements andbreak-
down performance criteria, but they also analyze extracts that usually contain
high-boilingcontaminants.While thesecontaminantsdonot always appear in the
GC/ECDchromatogram, theycancauseshifts in retention time, elevatedbaselines,
and target compound breakdown.
Pesticidemethods generally are analyzedusing two columns of different polarity
toprovide confirmation and increase confidence in reporting the presence of tar-
get analytes. To reduce analysis times, many labs prefer to run both columns
simultaneously using the same run conditions. However, this can be difficult be-
cause the run conditions for one column may not be optimum for the second,
confirmation column.
Althoughdual-column analyses canbe set up several differentways, Restek rec-
ommends a dual-column systemwhere the sample is injected into a single injec-
tion port via direct injection, vaporized in a hot injection port liner, transferred
ontoa5mSiltek
™
guardcolumn, andsplitonto the twocolumnsusingaglass“Y”
splitter. Siltek
™
deactivation provides the best inertness for chlorinated pesticide
analysis, minimizes endrin breakdown, and the 5m length allows enough of a
retention gap so that the sample is split evenly between the two columns. In a
conventional direct injection port using a Uniliner
®
glass sleeve, the guard col-
umn is connectedwith a press-tight seal at the bottom of the liner. This type of
injection port set-up eliminates contact of the analyteswith the activemetal sur-
Whyuse anRtx
®
-CLPesticides column?
The Rtx
®
-CLPesticides columns overcome
the coleution and component breakdown
problems that commonlyoccur inchlorinated
pesticide analysis. These columns provide
baseline resolution of target analytes, yield-
ing more accurate qualitative data without
GC/MSdetection.An analysis timeof under
25 minutes can increase sample throughput
by 15% compared to other columns. The
Rtx
®
-CLPesticides columns do not have the
problems associated with cyanopropyl
phases, such as on-column breakdown of
methoxychlor andDDT, and lowmaximum
operating temperatures. They have a high
maximum operating temperature (330°C),
which allows bake-out of high-boiling con-
taminants,andextendscolumn lifetime,mini-
mizesbaseline instability, and reduces instru-
ment maintenance.
Whichapplicationsworkwell using
Rtx
®
-CLPesticides columns?
These stationary phases are highly selective
for compounds that contain electronegative
substituents (halogenated compounds). The
Rtx
®
-CLPesticides columns not only work
well for chlorinated pesticides, but also for
chlorophenoxyherbicides, triazineherbicides,
haloacetic acids, andAroclor
®
mixtures.
