183 / 413
Figure 3
Improve BDE-209 response and
analysis times with optimized conditions
using the short column option.
• 9 •
2008 vol. 2
shows a greater response for BDE-209 and less peak fronting, indicating less
on-column breakdown.
Although the method originally stipulated that BDE-209 must elute at least 48
minutes from injection, eliminating the possibility of much method opti-
mization, a new revision provides a short column option which can greatly
improve analysis time and BDE-209 response. Since BDE-209 breaks down
primarily in the column, reducing column residence time by using a shorter
15m column, in combination with higher flows and quicker ramp rates, dra-
matically improves performance. Even applying optimized parameters to a
30m column results in greatly enhanced analyses, relative to the original
method-stipulated operating conditions. To further optimize this method,
BDE-209 degradation was reduced by using a maximum oven temperature of
less than 300°C and setting the injection temperature at 340°C, to ensure
complete vaporization, resulting in a consistent and high response (Figure 3).
In conclusion, the Rtx®-1614 is an excellent column choice for analyzing EPA
Draft Method 1614, as well as any routine screening analysis of PBDEs, due to
its selectivity, sensitivity, and inertness, specifically with respect to BDE-209.
Figure 2
More BDE-209 peak fronting on the method-specific column indicates greater on-column breakdown.
GC_EV01020
Column:
DB-5HT, 30m, 0.25mm ID, 0.10µm
Sample:
100-300ppb PBDE PAR Solution (cat.# EO-5113, Cambridge
Isotope Laboratories Inc.), 500ppb decabromodiphenyl
ether (cat.# BDE-209, Wellington Laboratories)
Inj.:
1µL splitless (hold 1 min.), 4mm cyclo double gooseneck
liner (cat.# 20896)
Inj. temp.:
300°C
Carrier gas:
helium, constant flow
Linear velocity: 20cm/sec. @ 100°C
Oven temp.:
100°C (hold 3 min.) to 320°C @ 5°C/min. (hold 15 min.)
Detector temp.: µ-ECD @ 340°C
Rtx®-1614 Columns (fused silica)
(5% phenyl methyl)
ID df (µm)
temp. limits
length cat. #
price
0.25mm 0.10 -60 to 330/360°C 15-Meter 10296
0.25mm 0.10 -60 to 330/360°C 30-Meter 10295
Splitless Liners for Agilent
ID* x OD & Length
qty.
cat.#
price
Cyclo Double Gooseneck (4mm)
4.0mm x 6.5mm x 78.5mm 5-pk.
20896
*Nominal ID at syringe needle expulsion point.
peak
tailing
Column:
Rtx
®
-1614, 15m, 0.25mm ID, 0.10µm (cat.# 10295)
Sample:
100-300ppb PBDE PAR Solution (cat.# EO-5113,
Cambridge Isotope Laboratories Inc.), 500ppb
decabromodiphenyl ether(cat.# BDE-209, Wellington
Laboratories)
Inj.:
1µL splitless (hold 1 min.), 4mm cyclo double gooseneck
liner (cat.# 20896)
Inj. temp.:
340°C
Carrier gas:
helium, constant flow
Linear velocity: 60cm/sec. @ 120°C
Oven temp.:
120°C (hold 1 min.) to 275°C @ 15°C/min. to 300°C
@ 5°C/min. (hold 5 min.)
Detector temp.: µ-ECD @ 345°C
GC_EV01025
Higher BDE-209
response—
3 times faster!
See Figure 1 for peak list.
See Figure 1 for peak list.
Lower response
than on Rtx®-1614