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2007.01
8-Minute Dual Column Analysis of Organochlorine Pesticides
Using Rtx®-CLPesticides / Rtx®-CLPesticides2 Columns
By Jason Thomas, Environmental Chemist
Rtx®-CLPesticides Column (fused silica)
ID df (µm)
temp. limits
length cat. #
price
0.18mm 0.18 -60 to 310/330°C 20-Meter 42102
$430
Rtx®-CLPesticides2 Column (fused silica)
ID df (µm)
temp. limits
length cat. #
price
0.18mm 0.14 -60 to 310/330°C 20-Meter 42302
$430
IP Deactivated Guard Column
length, ID
cat. #
price
5m, 0.53mm ID
10045
$60
Ferrules Fit Column ID
qty.
cat.#
price
0.25/0.28mm
kit
20276
$228
• Analysis and confirmation of 20 pesticides in 8 minutes.
• Baseline resolution of all compounds, for improved accuracy.
• Low-bleed columns, for reliable data.
Analyses for organochlorine pesticides are among the most common pesticide methodologies in use today. US EPA Method 8081,
for example, requires separation of 20 organochlorine pesticides, some of which are isomers or are otherwise structurally similar and,
therefore, are difficult to separate. Restek introduced two proprietary phases to address this issue, the Rtx®-CLPesticides phase and
the Rtx®-CLPesticides2 phase, which have proven very popular within the environmental community. The unique selectivities of this
column pair allow laboratories to significantly reduce analysis times for Method 8081.
There is a constant need for faster analyses, to help increase sample throughput and, thereby, increase productivity. Fast GC is a good
solution, but the reduced column internal diameters and thinner phase film coatings associated with fast GC have been deterrents, due
to concerns about the columns’ ability to cope with the harsh sample matrices often encountered in environmental samples, and short-
ened column lifetimes have not been acceptable.
Using a 0.53mm ID guard column at the inlet end
of a dual column configuration protects the ana-
lytical columns downstream. This configuration
allows 20m x 0.18mm ID thin film columns to be
used, with their associated high efficiency, to great-
ly reduce analysis time without the reduction of
column lifetime usually associated with introduc-
ing “dirty” samples into small bore columns.
Figure 1 shows separation of the 20 target pesticides
in EPA Method 8081 in 8 minutes using 20m x
0.18mm ID Rtx®-CLPesticides/Rtx®-CLPesticides2
columns with a 0.53 ID guard column. In addition
to rapid, baseline resolution, the pesticides are elut-
ed as sharp, symmetric peaks. This, in turn, helps
assure reliable quantification data for these analytes.
Clearly the Rtx®-CLPesticides/Rtx®-CLPesticides2
columns, in conjunction with a 0.53mm ID guard
column, are an excellent choice for analyzing EPA
Method 8081 pesticides, or equivalent target lists of
these pesticides.
Figure 1
20 organochlorine pesticides resolved and confirmed
in 8 minutes, using Rtx®-CLPesticides/Rtx®-CLPesticides2 columns.
3.0
4.0
5.0
6.0
7.0
8.0
GC_EV00892
GC_EV00893
3.0
4.0
5.0
6.0
7.0
8.0
SeCure™“Y”Connector Kits
Column:
Rtx
®
-CLPesticides, 20m, 0.18mm ID, 0.18µm (cat.# 42102) (top) and
Rtx
®
-CLPesticides2, 20m, 0.18mm ID, 0.14µm (cat.# 42302) with 5m x 0.53mm ID
intermediate-polarity deactivated guard tubing (cat.# 10045), connected using
SeCure
™
“Y” Connector Kit (cat.# 20276) with Universal “Y” Press-Tight
®
Connector
Sample:
Organochlorine Pesticide Mix AB #2 (cat.# 32292), 8-80µg/mL each component in hexane/
toluene, Pesticide Surrogate Mix (cat.# 32000), 200µg/mL each component in acetone
Inj.:
0.5µL splitless (hold 0.75 min.), 2mm single gooseneck inlet liner (cat.# 20795)
Inj. temp.:
250°C
Carrier gas:
helium, constant flow
Linear velocity: 20cm/sec. @ 140°C
Oven temp.:
140°C (hold 1 min.) to 250°C @ 35°C/min. (hold 1 min.) to 330°C @ 35°C/min. (hold 3 min.)
Det.:
ECD @ 350°C
1. 2,4,5,6-tetrachloro-
m
-xylene (surr.)
2.
α
-BHC
3.
γ
-BHC
4.
β
-BHC
5.
δ
-BHC
6. heptachlor
7. aldrin
8. heptachlor epoxide
9.
γ
-chlordane
10.
α
-chlordane
11. endosulfan I
12. 4,4’ DDE
13. dieldrin
14. endrin
15. 4,4’ DDD
16. endosulfan II
17. 4,4’ DDT
18. endrin aldehyde
19. endosulfan sulfate
20. methoxychlor
21. endrin ketone
22. decachlorobiphenyl
(surr.)
10
12
11
13
14
15 16 17
18
20
19
21
22
1
2
5 6
7
8 9
3
4
22
21
20
19 18
17 16
15
14
13 12
10
11
1
2
8 9
4
3 5 6 7
Dual column analysis in
less than 8 minutes!