1. Monitoring and identification of
hazardous air pollutants by fast capillary
gas chromatography with PID/FID
detection
1
J . N. DRISCOLL, & J.L. MACLACHLAN , PID
A N A LY Z E R S , L L C , S A N D W I C H , M A
&
S TA N L E Y S T E A R N S , VA L C O
INSTRUMENTS, INC., HOUSTON, TX
H T T P : / / W W W. H N U. C O M
A C S N AT I O N A L M E E T I N G , P H I L . , PA A U G .
2012
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2. What are Hazardous Air Pollutants (HAP’s)?
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 There are 187 hazardous air pollutants that range
from gases such as ETO to semivolatiles like
biphenyl that has a BP of 255.oC
 EPA has issued rules & regulations covering more
than 80 categories of major industrial sources, such
as chemical plants, oil refineries, aerospace
manufacturers, and steel mills, as well as categories
of smaller sources, such as dry cleaners, &
commercial sterilizers
 Monitoring of these species will be necessary to
comply with EPA regulations
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3. Introduction
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 Much of the previous work on “fast GC” utilized short (5M) thin film
capillary columns to elute solutes quickly and the result is rapid but
inferior separations because of the short column. New technology
developed at Valco’s capillary column development center where VICI
takes polyimide-coated fused silica (FST) and removes the polyimide
layer. Then the (FST) is electroplated with nickel. As a result of the
superior heat transfer of the electroplated nickel, we are able to rapidly
and efficiently heat and achieve excellent resolution for a 30M capillary
column.
 These columns can be programmed faster (hundreds of degrees/min)-
save 50-90%
 The columns can be reliably started a few degrees above ambient
 These columns cool down faster because of their low mass so savings>
50%
 Stearns et al (J. Chromat.) have looked at high MW HC but we are
looking at applications for gases & semivolatiles with thick film (5-10 )
capillary columns
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4. Resistively Heated Column
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 There are two types:
 a wire wrapped- where a Ni wire is wrapped with a fused silica
column and covered with an insulator
 B. where the column is coated with Ni then coated with
polyimide
The performance of the latter is somewhat better but the former
has a lower cost
These are available in short (5M) or long (30M) capillary
columns in a variety of bonded liquid phases
They are also available as PLOT column with various Hayesep
packings
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5. Photo GC 301 C
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6. Applications
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 Our applications at PID are in lower MW HC up to C6
solvents and semivolatiles. Here we have to start just
above to ambient, a difficult task for most GC’s, w/o
subamb. We were able to start @ 23oC
(reproducibly), hold 1 min, then prog. to 200oC (at
40C/min.) & hold for 1-2min. to complete. With a thick
film column (5 ), we could easily separate gases and
light solvents.
 For larger molecules, we would need a thin film 0.5
resistively heated column.
 Since these columns can be controlled separately, it is
possible to have two different columns and two
detectors running at the same time.
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7. Fast GC Chromatogram for C1 to C6 alkanes
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8. PID FID Ratios
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PID/FID Ratios
PID/FID Series Schematic
(f) # of Double Bonds
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9. Complex LNG sample GC PID/FID
(Packed column)
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10. PID FID Rations for LNG Sample
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Peak # Type PH-PID PH-FID PID/FID
Ratio
1 IP> 10.2 eV NR OR --
2 IP> 10.2 eV NR OR --
3 IP> 10.2 eV NR OR --
4 Aliphatic 220 54 4
5 Aliphatic 180 57 3.2
6 Aliphatic 88 17 5.1
7 Olefin 52 4 13
8 Aliphatic 104 17 6.1
9 Aromatic- Bz 256 5 51.2
10 Aromatic- Tol 308 4 77
11 Aromatic 132 3 44
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Aromatic 64 2 32

11. PID/FID Capillary Chromatograms of
Aromatics
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12. PID/FID Ratios (note PID scale is set 80x less
sensitive than the FID)
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# Component PID FID PID/FID
Ratio
1 toluene 33 28 94
2 ethyl benzene 20 37 43.2
3 m- xylene 28 36 62
4 tmbenz 39 35 89
5 styrene 27 38 78
6 i prop Tol 15 32 37.5
7 1,2,4 TMT 19 36 42
8 but benz 23 39 47
9 br- benz 29 18 128
10 1,2,4 TMB 13 12 87
11 1,2,3 TMB 12 12 80
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naphthalene 26 29 72

13. Solvents (BTX + MeOH) GC-PID/FID
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14. Conclusions
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 We have shown that with low MW HC- there is a >50% reduction
in analysis times
 There are eight different ramps that can be programmed so that
separations can be improved in different sections of the
chromatograms
 Although we have worked with thick films, these columns are
available with thin films for high MW compounds and with PLOT
columns for separation of low MW gases. Note that two columns
can be run simultaneously for volatiles & semivolatiles or polar
and non polar compounds to expand the detection of multiple
compounds
 PID/FID analyses provides an opportunity to positively identify
the solutes during the analytical process. Note the large
differences in PID/FID rations in slide #12. These can be used for
positive identification of a HAP in the chromatogram
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