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• 3 • 800-356-1688 • 2004 vol. 3
A cyclo double gooseneck splitless liner allowed
the samples to be completely volatilized in the
injection port prior to transfer into the column,
and achieved more reproducible results than
standard straight splitless liners. A liner with an
internal diameter of 2mm worked best with
0.5µL injections. We found that changing the
splitless hold time by several seconds could
reduce sensitivity by 50%. A pulsed splitless
analysis using a pressure pulse 5psi higher than
the column backpressure dramatically improved
sample transfer onto the column. We extended
the pulse 3 seconds (0.05 min.) past the split-
less hold time (0.15 min.) to allow excess sol-
vent to be swept away quickly.
We adjusted GC conditions to resolve analytes
that coelute and share ions. Phenol and aniline,
for example (peaks 5 and 6), were resolved by
using an initial ramp rate of 14°C/ min. The key
to resolving benzo(b)fluoranthene from
benzo(k)fluoranthene (peaks 83 and 84) is to
ensure that these analytes elute during the tem-
perature ramp part of the program. If they elute
during the final hold time they tend to exhibit
band broadening, which affects resolution.
Six reference mixes, including 8270 MegaMix™
calibration mix, were combined to prepare the
sample for the analysis in Figure 1. We have
carefully determined the components of the
MegaMix™ calibration mix for maximum stability.
We use highly purified methylene chloride as the
solvent, to avoid possible reactions between
analytes and trace impurities in the solvent.
Because 3-methylphenol and 4-methylphenol
coelute, we include each in the MegaMix ™ mix at
half the concentration of the other components,
to enable the user to calibrate at lower levels to
quantify these compounds at the required limits.
N-nitrosodiphenylamine, a target compound in
Method 8270D, readily oxidizes to diphenylamine
and nitric oxide, a highly reactive gas that can
participate in many chemical reactions or act as
a catalyst for other oxidation and reduction
reactions in the mix. Consequently, we include
diphenylamine, rather than N-nitrosodipheny-
lamine, in the 8270 MegaMix™ mix, to prevent
degradation of other components within the mix.
Another target compound, diphenylhydrazine,
also oxidizes easily, forming azobenzene, so we
include azobenzene, not diphenylhydrazine, in
the 8270 MegaMix™ mix to assure stability. The
stability of an unopened ampul of 8270
MegaMix™ mix, 18 months, is determined by
real-time analysis. In addition to the best choice
for analytical column, and stable calibration mix-
tures, we also have available internal standards,
surrogate standards, and other reference mixes
recommended for analyses of semivolatiles.
If you are analyzing for semivolatile compounds
by a GC/MS method, we recommend you evalu-
ate a 0.18mm ID Rtx®-XLB column, and Restek
reference mixes, for highest productivity and
most reliable data.
*3-methylphenol and 4-methylphenol concentration is
500µg/mL.
8270 MegaMix™ (76 components)
Each 5-pk. 10-pk.
1,000µg/mL each (except where noted) in methylene
chloride, 1mL/ampul*
31850 $108.20 31850-510 $486.90 —
w/data pack
31850-500 $118.20 31850-520 $541 31950 $973.80
Benzoic Acid
Each 5-pk. 10-pk.
31415 $21.70 31415-510 $96 —
w/data pack
31415-500 $32 31415-520 $106.60 31515 $191.90
Benzidine
Each 5-pk. 10-pk.
31441 $21.70 31441-510 $96 —
w/data pack
31441-500 $32 31441-520 $106.60 31541 $191.90
2-fluorophenol
phenol-d6
2,4,6-tribromophenol
Acid Surrogate Mix (4/89 SOW)
Each 5-pk. 10-pk.
2,000µg/mL each in methanol, 1mL/ampul
31025 $23.70 31025-510 $103.60 —
w/data pack
31025-500 $34 31025-520 $114.70 31125 $201
10,000µg/mL each in methanol, 1mL/ampul
31063 $39.20 31063-510 $173.60 —
w/data pack
31063-500 $49.50 31063-520 $193.90 31163 $338
10,000µg/mL each in methanol, 5mL/ampul
31087 $106.10 31087-510 $471 —
w/data pack
31087-500 $116.40 31087-520 $522.80 31187 $913.50
2-fluorobiphenyl
nitrobenzene-d5
p-terphenyl-d14
**Requires warming and sonication before use.
B/N Surrogate Mix (4/89 SOW)
Each 5-pk. 10-pk.
1,000µg/mL each in methylene chloride, 1mL/ampul
31024 $23.70 31024-510 $103.60 —
w/data pack
31024-500 $34 31024-520 $114.70 31124 $201
5,000µg/mL each in methylene chloride, 1mL/ampul**
31062 $39.20 31062-510 $173.60 —
w/data pack
31062-500 $49.50 31062-520 $193.90 31162 $338
5,000µg/mL each in methylene chloride, 5mL/ampul**
31086 $106.10 31086-510 $471 —
w/data pack
31086-500 $116.40 31086-520 $522.80 31186 $913.50
2,4-Dinitrophenol
Each 5-pk. 10-pk.
31291 $21.70 31291-510 $96 —
w/data pack
31291-500 $32 31291-520 $106.60 31391 $191.90
acenaphthene
acenaphthylene
aniline
anthracene
azobenzene
benzo(a)anthracene
benzo(a)pyrene
benzo(b)fluoranthene
benzo(ghi)perylene
benzo(k)fluoranthene
benzyl alcohol
benzyl butyl phthalate
bis 2-ethylhexyl adipate
bis(2-chloroethoxy)methane
bis(2-chloroethyl)ether
bis(2-chloroisopropyl)ether
bis(2-ethylhexyl)phthalate
4-bromophenyl phenyl ether
carbazole
4-chloroaniline
4-chloro-3-methylphenol
2-chloronaphthalene
2-chlorophenol
4-chlorophenyl phenyl ether
chrysene
dibenzo(a,h)anthracene
dibenzofuran
1,2-dichlorobenzene
1,3-dichlorobenzene
1,4-dichlorobenzene
2,4-dichlorophenol
diethyl phthalate
dimethyl phthalate
2,4-dimethylphenol
1,2-dinitrobenzene
1,3-dinitrobenzene
1,4-dinitrobenzene
4,6-dinitro-2-methylphenol
2,4-dinitrophenol
2,4-dinitrotoluene
2,6-dinitrotoluene
di- n-butyl phthalate
di- n-octyl phthalate
diphenylamine
fluorene
fluoranthene
hexachlorobenzene
hexachlorobutadiene
hexachlorocyclopentadiene
hexachloroethane
indeno(1,2,3-cd)pyrene
isophorone
1-methylnaphthalene
2-methylnaphthalene
2-methylphenol
3-methylphenol*
4-methylphenol*
naphthalene
2-nitroaniline
3-nitroaniline
4-nitroaniline
nitrobenzene
2-nitrophenol
4-nitrophenol
N-nitrosodimethylamine
N-nitroso-di- n-propylamine
pentachlorophenol
phenanthrene
phenol
pyrene
pyridine
2,3,4,6-tetrachlorophenol
2,3,5,6-tetrachlorophenol
1,2,4-trichlorobenzene
2,4,5-trichlorophenol
2,4,6-trichlorophenol
Inlet Liners
For Agilent GCs
Cyclo Double Gooseneck
(2.0mm ID, 6.5mm OD, 78.5mm length)
20907 (ea.)
20908 (5-pk.)
For PerkinElmer GCs
Splitless
(2.0mm ID, 5.0mm OD, 100mm length)
20730 (ea.)
20731 (5-pk.)
20732 (25-pk.)
For Thermo Finnigan 5000-6000 GCs
Splitless
(2.0mm ID, 5.4mm OD, 79.5mm length)
20811 (ea.)
20812 (5-pk.)
20813 (25-pk.)
For Varian 1075/1077GCs
Splitless
(2.0mm ID, 6.3mm OD, 74mm length)
20721 (ea.)
20722 (5-pk.)
20723 (25-pk.)