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Figure 1
Excellent resolution of chlorophenoxyacid herbicides on the Rtx®-CLPesticides column pair.
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6
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2008 vol. 1
Environmental
Rtx®-CLPesticides2
11. pentachloroanisole
12. 2,4,5-TP methyl ester
13. 2,4,5-T methyl ester
14. chloramben methyl ester
15. 2,4-DB methyl ester
16. dinoseb methyl ester
17. bentazon methyl ester
18. DCPA
19. picloram methyl ester
20. acifluorfen methyl ester
C. contaminant
GC_EV00971A
The analysis of chlorophenoxyacid herbicides is a very common assay performed routinely in most environmental laboratories today.
Chlorophenoxyacid herbicides, as a group, are used to prevent the growth of broadleaf plants in agricultural fields. EPA Method
8151A is commonly used for chlorophenoxyacid herbicide analysis and involves extraction and derivatization to methyl ester form.
GC analysis using an electron capture detector (ECD) is the analytical procedure of choice, although mass spectrometry is also used.
ECD detection requires the use of second column confirmation for quantification of target analytes.
The Rtx®-CLPesticides and Rtx®-CLPesticides2 column pair is an excellent choice for chlorophenoxyacid analysis. Now, with an
optimized film thickness for the 0.32mm ID version, this difficult analysis can be made in less than 13 minutes on both the primary
and confirmation columns. Near baseline resolution is achieved for all analytes except for bentazon/picloram on the Rtx®-
CLPesticides column; however, this pair is fully resolved on the Rtx®-CLPesticides2 column (Figure 1). The Rtx®-CLPesticides and
Rtx®-CLPesticides2 column pair is an excellent choice for chlorophenoxyacid herbicide analysis due to the unique selectivity, low
bleed, and durability of the columns. The Rtx®-CLPesticides column pair can also be used for other environmental ECD methods,
including chorinated pesticide analysis.
13 Minute Chlorophenoxyacid Herbicides Analysis
On New Rtx®-CLPesticides & Rtx®-CLPesticides2 Columns
By Jason Thomas, Environmental Innovations Chemist
• Higher throughput compared to typical methods of 20 minutes or more.
• Use one column pair for multiple dual column ECD methods.
• Versatility and durability to harsh samples lead to longer life and less down time.
min.
min.
GC_EV00971
1. dalapon methyl ester
2. 3,5-dichlorobenzoic acid methyl ester
3. 4-nitroanisole
4. DCAA methyl ester (SS)
5. dicamba methyl ester
6. MCPP methyl ester
7. MCPA methyl ester
8. dichlorprop methyl ester
9. 4,4'-DBOB (IS)
10. 2,4-D methyl ester
Column:
Rtx
®
-CLPesticides2, 30m, 0.32mm ID, 0.25µm (cat.# 11324) and
Rtx
®
-CLPesticides, 30m, 0.32mm ID, 0.32µm (cat.# 11141), with
5m x 0.32mm ID Rxi
®
deactivated guard tubing (cat.# 10039),
connected using Deactivated Universal “Y” Press-Tight
®
Connector (cat.# 20405-261)
Sample:
200ng/mL Herbicide Mix #1 (cat.# 32055) in hexane
1,000ng/mL Herbicide Mix #2 (cat.# 32057) in hexane
20,000ng/mL Herbicide Mix #3 (cat.# 32059) in hexane
200ng/mL Herbicide Mix #4 (cat.# 32062) in hexane
250ng/mL Herbicide Internal Standard (cat.# 32053) in hexane
400ng/mL Herbicide Surrogate (cat.# 32050) in hexane
Inj.:
1.0µL splitless (hold 0.75 min.),
4mm Cyclo Double Gooseneck inlet liner (cat.# 20895)
Inj. temp.: 250°C
Carrier gas: helium, constant pressure
Flow rate:
36cm/sec. @ 70°C
Oven temp.: 70°C (hold 0.5 min.) to 190°C @ 25°C/min. (hold 1 min.)
to 300°C @ 11°C/min. (hold 5 min.)
Det.:
ECD @ 325°C
Rtx®-CLPesticides
<13 min.
chlorophenoxyacid
herbicide analysis!
NEW
—
Optimized Film
Thicknesses!
Fully resolve bentazon and
picloram methyl esters