0 7 14 21 28 35 42 49 56 63 70 77 84 91 98
Number of Injections
.
.
.
.
...
.
. . . .
. . .
Figure 3
The Stabilwax
®
column combinedwith aUniliner
®
sleeve shows remarkable response consistency.
The Stabilwax
®
column can easily handle
direct aqueous injectionswithout showing
any signs of degradation. Testing of the
Stabilwax
®
columnwas performed by inject-
ing 1µLof awater standard 100 times. Peak
shape and response of ethylene and propy-
lene glycol remained consistent throughout
the analyses (
Figures 2 and 3
). The
Stabilwax
®
column also allows sensitive
detection of low ppm-levels of glycol com-
pounds. Notice the 5ppm detection limit for
ethylene glycol inwater is easily achieved,
and peak shape ismaintainedwhen com-
pared to a 25ppm standard (
Figure 4
).
Conclusion
You can achieve better response and repro-
ducibility for theGC analysis of ethylene
glycol inwater by using direct injectionwith
aUniliner
®
sleeve, a polar capillary column
such as Stabilwax
®
, andmultiple syringe
washes between runs. Using these tech-
niques can assist in attaining reproducible
analyseswith detection limits in the low
ppm range.
30m, 0.53mm ID, 1.0µmStabilwax (cat.# 10655)
1.0µLof ethylene glycol and propylene glycol sample
inwater. Open-topUniliner direct injection liner with-
out wool (cat.# 20843-205).
Concentration:
100ppm
Instrument:
Agilent 5890w/7673Autosampler
Oven temp.:
80°C (hold 1min.) to 200°C@
8°C/min. (5.0min.)
Inj./det. temp.:
225°C/250°C
Carrier gas:
helium
Linear velocity:
50cm/sec.
Detector:
FID
SeptaPurge:
5.0cc/min.
8.0 9.0 10.0 11.0
750000
700000
650000
600000
550000
500000
450000
400000
.
AreaCounts
propylene glycol
ethylene glycol
ethylene glycol
propylene glycol
~
Figure 2
The Stabilwax
®
column shows good peak shape and response
for ethylene glycol after 100 injections.
Average
Average
