Figure3
Lowbleedandexceptional inertness ensureexcellent results for organochlorinepesticides inUS
EPAMethod8081.
1. 2,4,5,6-tetrachloro-
m
-xylene (ss)
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. endrin aldehyde
18. 4,4'-DDT
19. endosulfan sulfate
20. methoxychlor
21. endrin ketone
22. decachlorobiphenyl (ss)
GC_EV00720
Rtx
®
-XLB 30m, 0.32 ID, 0.5µm (cat.# 12839)
Sample:
Organochlorine PesticideMix AB (cat.# 32292) 80/160ppb in hexane
2,4,5,6-tetrachloro-
m
-xylene (cat.# 32027) surrogate, 80ppb
decachlorobiphenyl (cat.# 32029) surrogate, 160ppb
Inj.:
1.0µL splitless (0.75min. hold), 4mmDrilledUniliner
®
inlet liner (cat.# 21055)
Inj. temp.:
220°C
Carrier gas:
hydrogen, constant pressure
Linear velocity: 60cm/sec.@ 120°C
Oven temp.:
120°C (hold 0.5min.) to 260°C@ 29°C/min. (hold 2.5min.), to 330°C@ 28°C/min. (hold 3min.)
Det.:
ECD@ 320°C
Excellent Choice forOrganochlorinePesticides
Inmanyenvironmental and food laboratories, samplesareanalyzed fororganochlorinepesticidesusinghighly sensitiveelectroncap-
ture detectors (ECDs). In order to take full advantage of the detector's sensitivity, the analytical columnmust exhibit low bleed, to
minimize backgroundnoise, and exceptional inertness, toprevent loss of labile pesticides, in addition to the selectivitynecessary to
separate complexmixtures. Low bleed and excellent inertness make an Rtx®-XLB column the perfect choice for this application.
Figure3andFigure4 (overside) showanRtx®-XLBcolumnwill separatecomplexmixturesof organochlorinepesticides.Table I lists
retention times for the extended list of analytes.
tech
tip
In combinationwith anRtx
®
-XLB column, a few simple adjustments to injection conditions can greatly improve sensitivity for active and
highmolecularweight target compounds:
* By eliminating contact between the sample and the hotmetal surfaces in the injection port, aDrilledUniliner
®
inlet liner prevents
analytes from degrading in the injection port. For information about DrilledUniliner
®
inlet liners, request lit. cat.# 59877, or refer to
our current chromatography supplies catalog.
* Pulsed injection also helpsminimize breakdown, by reducing the time the analytes spend in the injection port. A 30psi/0.5min. pulse
was used to obtain Figure 2.To avoid breaking the seal between the column and aDrilledUniliner
®
inlet liner, do not exceed 50psi.
* When analyzing semivolatile compounds, a 35ºC initial temperature helps ensure sharp, symmetric peaks for early-eluting analytes
(Figure 2).
