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7 EPAMethods on 1 Column Pair
Analyze Pesticides, PCBs, Herbicides and More on a Single Rtx®-CLPesticides Column Set
By Jason Thomas
• Spend more time analyzing samples
and less changing columns.
• Avoid downtime associated with
dedicated instruments.
• Best performance of any column
set offered specifically for multiple
GC-ECD methods.
update with new imagery
when available from Chris
Although many new techniques, or previ-
ously underutilized ones, are coming into
greater use in environmental labs to combat
ever more complicated sample lists and dif-
ficult sample matrices, the electron capture
detector (ECD) remains an important and
powerful tool in determining the presence of
many compounds of environmental concern.
The ECD is a simple, inexpensive detector
that provides excellent sensitivity for envi-
ronmental compounds that are halogenated
or contain other electron withdrawing func-
tionalities. Because of this compound class
selectivity, target environmental analytes can
be detected without much interference from
the sample matrix, an issue that can be prob-
lematic using less selective detectors.
Numerous environmental contaminants are
halogenated, and many tend to be quite
toxic. Although some of these, like diox-
ins, are analyzed using HRMS for increased
specificity, many EPA methods have been
developed for pesticides, PCBs, DBPs, and
other similar compounds using the ECD.
These methods tend to use a column pair,
where one column serves as a confirmation
column in the event a target contaminant
needs to be positively identified and quanti-
fied. One such pair, the Rtx®-CLPesticides
Table I: Rtx®-CLPesticides columns offer the best performance for multiple GC-ECD methods.
EPA Method Column Pair Analysis
Time (min.) Coelutions Restek Advantage
8081B
(Organochlorine
pesticides)
Rtx-CLPesticides/
Rtx-CLPesticides2
7/7 0/0 • Increase sample throughput with 7 min. analyses.
DB-35ms/DB-XLB 15/16 0/0
ZB-MR1/ZB-MR2 10/9 0/0
8081B**
(extended)
(Organochlorine
pesticides)
Rtx-CLPesticides/
Rtx-CLPesticides2
24/23 1/2 • Best balance of speed and selectivity.
• All compounds are resolved between both columns.
DB-35ms/DB-XLB 42/39 2/3
ZB-MR1/ZB-MR2 NDP/16 NDP/3
8082A
(Polychlorinated
biphenyls [PCBs],
Aroclors)
Rtx-CLPesticides/
Rtx-CLPesticides2
7/7 0/0 • AnalyzePCBs2xor3xfasterthanonotherECDcolumns.
DB-35ms/DB-XLB 14/16 0/0
ZB-MR1/ZB-MR2 24/21 0/0
8151A
(Chlorinated
herbicides)
Rtx-CLPesticides/
Rtx-CLPesticides2
13/13 1/0 • Increase sample throughput with fastest run time.
DB-35ms/DB-XLB 16/17 0/0
ZB-MR1/ZB-MR2 16/15 1/1
504.1
(EDB, DBCP,
TCP)
Rtx-CLPesticides/
Rtx-CLPesticides2
9/10 0/0 • Reliably separate analytes from trihalomethane
interferences.
DB-35ms/DB-XLB NDP NDP
ZB-MR1/ZB-MR2 NDP NDP
505
(Organohalide
pesticides)
Rtx-CLPesticides/
Rtx-CLPesticides2
18/18 1/1 • Fast, reliable analysis.
DB-35ms/DB-XLB NDP NDP
ZB-MR1/ZB-MR2 NDP NDP
508.1
(Chlorinated
pesticides,
herbicides,
organohalides)
Rtx-CLPesticides/
Rtx-CLPesticides2
23/24 2/2 • All compounds resolvedbetweenbothcolumns.
• Best overall balance of speed and resolution.
DB-35ms/DB-XL 22/24 2/4
ZB-MR1/ZB-MR2 18/NDP 2/NDP
552.2
(Haloacetic acids,
dalapon)
Rtx-CLPesticides/
Rtx-CLPesticides2
12/12 0/0 • Nocoelutions—getaccurateresultsforcompoundsthat
coeluteonothercolumns.
DB-35ms/DB-XLB 8/9 2/1
ZB-MR1/ZB-MR2 NDP NDP
Comparison based on published competitor data.
NDP = no data published
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