Envantage has developed a new GC Method translator that speeds development of Fast GC Methods. This presentation is a sampling of the presentation given at the 2011 Gulf Coast Conference. A few of the tools are described and a real-world analytical problem is given as an example

1. Fast Temperature Programmed Gas
Chromatography
of n-Paraffins through C14
GULF COAST CONFERENCE
Oct 11, 2011
Paper Presentation - 30 minutes – 2:30 PM: Abstract # 053
Walter Spieksma David Balazs Jay Grills
wspieksma@envantage.com
www.envantage.com

2. Envantage Method Translator
• Temperature programmed method translation
• Nitrogen, Helium and Hydrogen
• Dimethylsilicone or customized
• Predict performance by EMT first principles
• Real time demo after these slides
www.envantage.com 2

3. Envantage Method Translator
Walter began his talk by summarizing the main
features of the Envantage Method Translator
• Temperature programmed method translation
• Nitrogen, Helium and Hydrogen
• Dimethylsilicone or customized
• Predict performance by EMT first principles
• Real time demo after these slides
www.envantage.com 3

4. Envantage Method Translator
The Envantage Method Translator
(EMT) is an interactive tool that can be
used to help speed up gasoline range
GC methods by graphically displaying
quality measurements in a comparative
• Temperature programmed method translation
way
• Nitrogen, Helium and Hydrogen
• Dimethylsilicone or customized
• Predict performance by EMT first principles
• Real time demo after these slides
www.envantage.com 4

5. Envantage Method Translator time
This eliminates the expensive and
consuming process of trial and error
that must be used with other Method
Translators
• Temperature programmed method translation
• Nitrogen, Helium and Hydrogen
• Dimethylsilicone or customized
• Predict performance by EMT first principles
• Real time demo after these slides
www.envantage.com 5

6. Envantage Method Translator
The EMT does this by utilizing the Golay
equation and applying Boltzmann’s gas
diffusion laws as modified by Enskog-
Chapman while at the same time
considering the pneumatics of Hagen-
• Temperature programmed method translation
Poiseuille as well as….
• Nitrogen, Helium and Hydrogen
• Dimethylsilicone or customized
• Predict performance by EMT first principles
• Real time demo after these slides
www.envantage.com 6

7. Envantage Method Translator
….well…you get the idea. There are a lot
of chemical and gas properties behind this.
• Temperature programmed method translation
• Nitrogen, Helium and Hydrogen
• Dimethylsilicone or customized
• Predict performance by EMT first principles
• Real time demo after these slides
www.envantage.com 7

8. Envantage Method Translator
After describing the features of the
Envantage Method Translator Walter
demonstrated a few real-world examples
of analytical problems that can be
addressed using the EMT
• Temperature programmed method translation
• Nitrogen, Helium and Hydrogen
• Dimethylsilicone or customized
• Predict performance by EMT first principles
• Real time demo after these slides
www.envantage.com 8

9. Envantage Method Translator of the
In this excerpt of his talk just a few
EMT tools will be described and one
quick example will be given
• Temperature programmed method translation
• Nitrogen, Helium and Hydrogen
• Dimethylsilicone or customized
• Predict performance by EMT first principles
• Real time demo after these slides
www.envantage.com 9

10. Agilent Method Translator
This popular tool
has a nice interface
to enter the original
Method parameters
10

11. Agilent Method Translator
And new column
parameters
11

12. Agilent Method Translator
A new pressure and
temperature program
is translated and
displayed
12

13. Agilent Method Translator
But how do you
know how well this
translated Method
will perform?
13

14. Agilent Method Translator
As an example of how the
translator works the
documentation shows
comparison chromatograms
with clear differences
between them
Agilent Technologies, Inc., Application Note 228-294. 14

15. Agilent Method Translator
The column type and
dimensions are quite
different from each other so
the example is confusing
Agilent Technologies, Inc., Application Note 228-294. 15

16. Agilent Method Translator
Toggle back and forth
between this slide and the
next to see the differences
in the chromatogram
Agilent Technologies, Inc., Application Note 228-294. 16

17. Agilent Method Translator
Agilent Technologies, Inc., Application Note 228-294. 17

18. Agilent Method Translator
This tool is easy to use
and you will get a
chromatogram – but
what if you need the
new chromatogram to
look like the one in
your original Method?
18

19. Envantage Method Translator
The next 4 slides will show the Envantage Method
Translator interface and two “before and after”
chromatograms of an ASTM method that was translated
19

20. 20

21. Note:
•the quick assessment of Speed, Sensitivity, and Resolution
•the change in run time
•the similarity of the chromatograms
•comparable chromatographing power
21

22. TPGC D 6730 Take a look at the front end of a
chromatogram obtained by
analyzing a sample with a standard
ASTM Method, and the same
sample chromatogram after the
method has been optimized for
speed with the EMT (toggle this
slide with the next)
22

23. Fast TPGC
Going from 60 to 11 minutes is
considered by most to be a
pretty nice speed-up!
23

24. So let’s take a closer
look at the EMT
interface
24

25. First the table
25

26. The table has familiar
functionality:
a place to enter original
Method settings and
new Method settings
26

27. Any two
combinations of
Column Length,
Hold-up time, or
Head Pressure can
be “locked” so that
the third can be
calculated
27

28. Footnotes at the
bottom provide clues
to things you should
be aware of – like
high pressures the
instrument may not
be capable of
28

29. There are also
options to display
Column IDs in
mm, time in
seconds, and
pressures in
kPa, bar, or atm
29

30. Constant pressure,
velocity, or temperature
can be selected at the
bottom of the table
30

31. Next, let’s look at the “Trilemma” display
31

32. The “Trilemma” displays
the interdependence of
Speed, Sensitivity, and
Resolution when
translating a Gas
Chromatographic method
32

33. “Speed” (speed gain)
is the ratio of holdup
time of the original
method and the new
method. “Resolution”
is the peak width ratio.
“Sensitivity” is the
peak height ratio.
33

34. Speed gain can be
changed by the user
with the up and
down buttons; the
resolution and
sensitivity
consequences are
displayed.
34

35. Pressing the
“Optima” button
results in a speed
gain proportional to
the ratio of the
optimum velocities
of both methods.
The “Integer” button
rounds off speed
gain so that
temperatures and
ramps are not
fractional
35

36. The change of
Speed, Sensitivity,
and Resolution will
be displayed as the
carrier flow is
changed following
the first principles of
the trilemma of
chromatography.
36

37. The Trilemma display
will also change if
carrier flow changes
are made in the table
or by grabbing and
dragging the linear
velocity hash marks in
the “Plate Height” and
“Plate Number” tabs
37

38. Now let’s take a look
at some of these tabs;
in particular “Plate
Height”, “Plate
Number”, and
“Chromatogram”
38

39. Let’s consider the “Plate
Height” tab
39

40. When GC method
parameters are entered ,
EMT will calculate a HETP
curve of nC6 (similar to a
Van Deemter curve) and
locate the linear velocity.
40

41. Note the absence of the
Trilemma display. It does not
appear until settings for a
new Method are entered into
the 2nd column of the table.
41

42. As any good
chromatographer
knows - the lower
the HETP, the better
42

43. As expected this
ASTM Method is
operating at optimum
linear velocity for
this column length,
ID, film thickness,
and carrier gas
43

44. EMT also calculates
and draws a “Plate
Number” chart. The
number changes
depending on the
linear velocity of the
carrier gas.
44

45. More is better and the
best can be achieved
at the optimum linear
velocity of the carrier
gas
45

46. EMT also calculates
the retention times of
n-alkanes through
nC14 and displays
them graphically in a
“chromatogram”
46

47. Click on the Trenn
Zahl toggle to display
a Trenn Zahl chart
under the
chromatogram
47

48. What is a Trenn Zahl Chart?
www.envantage.com 48

49. It indicates how many peaks can elute between any two
n-alkanes
www.envantage.com 49

50. EMT calculates the peak widths of the theoretical n-
alkane peaks in the theoretical chromatogram and then
calculates how many peaks with a similar width can be
parked between any two n-alkane peaks
www.envantage.com 50

51. In this example almost 130
peaks can be parked
between n-C8 and n-C9
www.envantage.com 51

52. When optimizing Methods with complex chromatograms
this can be a useful tool to indicate the new Method has
the power to achieve the same separations as the original
method
www.envantage.com 52

53. So how well does the Envantage
Method Translator do all this
calculating?
www.envantage.com 53

54. EMT D 6733#1
This slide and the
next show
chromatograms
generated for ASTM
6733 #1 and #2 (one
cryogenic, one not)
54

55. EMT D 6733#2
55

56. D 6733 and EMT
(Calc-Exp) (Calc-Exp)
ASTM D 6733#1 EMT* ASTM D 6733#2 EMT**
x /Exp /Exp
tx [min.] tx [min.] % tx [min.] tx [min.] %
3 4.14 4.21 1.57 5.08 5.32 4.63
4 4.74 4.75 0.17 6.55 6.71 2.47
5 6.31 6.15 -2.50 11.12 11.02 -0.90
6 10.40 9.87 -5.13 23.39 23.07 -1.37
7 19.36 18.52 -4.34 40.58 40.42 -0.39
8 33.01 32.35 -2.00 57.70 57.80 0.17
9 48.85 48.71 -0.29 72.88 73.23 0.48
10 64.86 65.35 0.76 85.54 86.10 This table shows how
0.65
11 80.17 81.39 1.52 95.59 97.47 well the EMT
1.97
12 93.50 95.18 1.80 107.81 107.90 calculated retention
0.08
times compare to the
ASTM published
* Pgage = 192 kPa to get: (1) 18.5< t7 <20.3 (2) 32< t8 <34 (3) 92.8< t12 < 95.2 min.
www.envantage.com
values
**Pgage = 150 kPa to get: (1) 39.5< t7 <42.0 (2) 57< t8 <59 (3) 106.4< t12 <108.8 min.
56

57. TPGC retention time of n-Paraffins
EMT retention time
180
160
Envantage Method Translator [min]
140
120
100
80
This chart plots how
60 well the EMT
calculated retention
40 times for several
samples correlate
20 with ASTM DHA
values
0
0 20 40 60 80 100 120 140 160 180
ASTM [min] 57

58. To use the Envantage
Method Translator enter
original Method settings in
the left column, and new
Method settings in the
second column
58

59. When parameters for a new
Method are entered the
Trilemma display appears and
comparative charts and graphs
appear in the “Plate
Height”, “Plate Number”, and
“Chromatogram” tabs
59

60. Hash marks indicating the
linear velocity can be
“grabbed” with the mouse and
dragged. Head pressure will
change in the table and the
Trilemma display will show
the effects of this change
60

61. On the “Plate Number”
tab, hash marks indicating
linear velocity can also be
“grabbed” with the mouse and
dragged. In this example the
new Method has significantly
more plates and indicates the
column can be shortened to
achieve the same separation as
the original method
61

62. On the
“Chromatogram” tab
two chromatograms
appear
and, optionally, the
Trenn Zahl chart. If the
peaks line up and the
Trenn Zahl charts are
very similar then the
new Method may be a
good replacement for
the original Method.
62

63. And now for a real-world example…..
ASTM with H2 carrier
• Helium prices rise for 10 years now
• Advice: Change to Hydrogen carrier; use
the same head pressure you used with
helium
www.envantage.com 63

64. Chromatographers are often advised
to simply switch to Hydrogen carrier
gas and keep the same carrier gas
pressures used with helium. If you
ever tried this and met with poor
success – maybe this is why…..
www.envantage.com 64

65. Keep P
In this example the same column
dimensions are entered in both columns
of the table, making sure the column head
pressure is the same and only the carrier
gas is different
www.envantage.com 65

66. Optima
Keep P
With Hydrogen
the Method is
more sensitive
But there is less
www.envantage.com separation 66

67. By inspecting
the linear
velocity on the
“Plate Number”
tab it is obvious
the column
flow is not
optimum
67

68. Click and drag
the hash line or
click on
“Optima” in the
Trilemma
display
68

69. Optimum Chromatograms
Note the new head
pressure; now the
sensitivity is the
just about the same
And, more importantly, the
separation is now the same.
Your new chromatogram
should match the old!www.envantage.com 69

70. Optimum Chromatograms
Next, you might be
wondering if you
can shave more
time off this
Method by
adjusting the
column dimensions
www.envantage.com 70

71. The answer is…..probably.
But that’s another real-world example
www.envantage.com 71

72. More information about the
Envantage Method Translator will be
posted soon on our web site
www.envantage.com 72