Introduction - Agilent€¦ · 3 Agilent Technologies Sales & Services GmbH & Co. KG -Hewlett...
Transcript of Introduction - Agilent€¦ · 3 Agilent Technologies Sales & Services GmbH & Co. KG -Hewlett...
ISCC 2014
Poster # N.06 Expanding analytical capabilities for laboratory GC
through the use of an external isothermal zoneJuan
Aybar1, James McCurry2, Bernhard Rothweiler3
1 Agilent Technologies, Carretera Nacional VI, Km 18.2, 28232 Las Rozas, Spain 2 Gas Phase Division – Agilent Technologies, 2850 Centerville Road, 19808 Wilmington, United States
3 Agilent Technologies Sales & Services GmbH & Co. KG - Hewlett-Packard-Str. 8, Waldbronn, 76337, GERMANY
Introduction
Complex GC applications can require using multiple valves for column switching, heart cutting, and multi-dimensional analysis. Similarly, columns used for certain application
have temperature limitation for packing materials or stationary phase films. The addition of a large valve oven to the 7890B GC provides an external isothermal zone
addresses these requirements. Capable of supporting a combination of up to six (6) column mandrels of valves the large valve oven provide thermal regulation up to 300 °C.
When applied to Refinery Gas Analysis (RGA) the new system provides stable response for oxygen (O2) and hydrogen disulfide (H2S) with profiling of hydrogen,
hydrocarbons (C6+ as backflush), and permanent gases in eight (8) minutes using micropacked columns, and seventeen (17) minutes using standard packed columns. The
additional capacity for multiple valves and columns in a single heated zone also allows for the analysis of reformulated fuels per ASTM D3606, D4815 and D5580.
Experimental
Table 2. Select method
conditions for LVO Reformulated
Fuels Analyzers
Instrument Agilent 7890B GC for RGA
Splt/Splitless Inlet 120℃, 100:1 Split
FID (front) 250℃
TCD (rear) 260℃, He carrier,
Ref. 30 mL/min, Makeup 2 mL/min
TCD (side) 250 ºC, N2 carrier
Ref. 45 mL/min, Makeup 2 ml/min
Negative Polarity
Main Oven Program 60 ºC ( 1 min) to 80 ºC @ 20 ºC/min
to 190 ºC @ 30 ºC/min
LVO Program Isothermal, 65 ºC and 70 ºC
Method performance
Results and Discussion
Refinery Gas Analysis Maintenance of isothermal temperature in the LVO allow for simultaneous
reproducible determination of H2S and O2. Run time for the Fast and Standard
RGA configurations is 8 and 16 minutes respectively. Figure 5 depicts
chromatography and reproducibility data for the LVO RGA with Standard 1/8”
columns. Table 3 summarizes reproducibility data for the LVO RGA with Standard
1/8” columns.
Large Valve Oven
The new Large Valve Oven for the 7890B GC expands the analytical capacity and
provides flexibility for GC methods that require complex valve and multiple column
configurations. The isothermal zone provides reproducible analysis of RGA
components and simultaneous detection of H2S and O2. The LVO allows multiple
ASTM gasoline methods to be configured on a single GC. Run sequentially , the
methods meet or exceed ASTM performance requirements. Higher main oven
temperature (135 °C) has no effect on the lower LVO temperature (60 °C).
Conclusion
Large Valve Oven Refinery Gas Analysis
This work developed application for Refinery Gas (RGA) analysis using
Micropacked columns and standard packed columns. Table 1 outlines select
analytical conditions for the RGA systems.
Similarities Between Each Reformulated Fuel Methods
All method have the same GC hardware requirements, e.g., Inlets, detectors,
plumbing and valve configuration same separation scheme:
• 2-D separation using polar TCEP micro-packed primary column
• 20% TCEP on 80/100 Chromosorb PAW, 22“ x 1/16“ stainless
• Only one difference in instrument requirements – non-polar capillary column
• D4815 – 2.65 mm methyl silicone, 30m x 0.53mm
• D5580 – 5 mm methyl silicone, 30m x 0.53mm
Large Valve Oven (LVO)
The LVO expands the analytical capabilities of the standard GC oven and
provides easy access for system maintenance. Using a single heated zone, this
accessory provides an isothermal zone to house six (6) heated internal positions
for valves or column mandrels, and four (4) needle valve positions. Figure 1
below shows the front and back of the LVO. Figures 2, 3 and 4 represent the
configurations for the Fast RGA, Standard RGA and Reformulated Fuels
analyzers respectively.
Fig 5. S/N for Dibenzo(a,l)pyrene (500 pg), CCM vs standard operation
Reformulated Fuel Analysis All three methods, D5580, D4815, and D3606 meet or exceed ASTM methods
performance criteria. Figure 6 below summarizes reproducibility data for all three
methods.
Fig 6. Performance Data for ASTM Methods
D5580 (top), D4815 (middle)and D3606 (bottom
right and left)
Large Valve Oven Reformulated Fuel Analysis
Leveraging the flexibility offered by the LVO, three (3) Reformulated Fuel
Analysis applications, ASTM D4815, D5580 and D3606., were configured on a
single GC. Table 2 reflects analytical conditions for each method.
Parameter D3606 Method`
carrier gas helium
Inlet Purge Packed @ 59.4 psi
Inlet temperature 200 Deg C
Inlet total flow 23 mL/min
Septum purge flow 3 mL/min
Column flow 20 mL/min
Aux pressure 35.5 psi
TCD temperature 250 deg C
LVO Temperature 60 deg C
Main oven temperature 135 deg C isothermal
Backflush time 2.5 min
Parameter D4815 Method D5580 Method
carrier gas helium or N2 helium or N2
Inlet Split/Splitless Split/Splitless inlet temperature 200 Deg C 200 Deg C
inlet pressure 9 psi (constant P) 25 psi (constant P) TCEP column flow 5 mL/min 10 mL/min
split vent flow 70 mL/min 100 mL/min
split ratio 15:1 100:1
PCM pressure program
13 psi for 14 min>99 psi/min to 40 psi
23 psi for 12.1 min>99 psi/min to 40 psi
HP-1 column flow 3 mL/min 10 mL/min
FID temperature 250 deg C 250 deg C
LVO temperature 60 deg C 60 deg C
Main oven temperature 60 deg C isothermal 60 C for 6 min>2 C/min to 115 C>115 C for 1.5 min
Table 1. Select method conditions for LVO Refinery Gas Analyzers
Figure 1. Base LVO configuration
Micropacked LVO Plumbing
Figure 2. LVO for Fast RGA,
micropacked columns Figure 3. LVO for Standard RGA, 1/8”
columns
Figure 4. LVO for Reformulated Fuels
Analysis (D4815, D5580, D3606
Compound Concentration RT 65 C RT 70 C Area 65 C Area 70 C
C6+ 0.06 0.026 0.022 0.35 0.31
Methane (FID) 4.99 0.009 0.011 0.19 0.12
Ethane (FID) 4 0.02 0.016 0.21 0.15
n-butane 0.3 0.103 0.038 0.23 0.16
t-2-butane 0.3 0.13 0.055 0.22 0.19
1-butene 0.3 0.13 0.056 0.34 0.26
n-pentane 0.1 0.082 0.034 0.29 0.22
Hydrogen 12.1 0.021 0.037 0.13 0.1
Oxygen 2.98 0.015 0.01 1.36 0.7
Nitrogen balance 0.026 0.017 0.18 0.12
Carbon Monoxide 1.52 0.044 0.023 0.16 0.12
Carbon Dioxide 2.01 0.11 0.048 0.13 0.14
Methane (TCD) 4.99 0.031 0.02 0.25 0.13
Ethane (TCD) 4 0.099 0.055 0.22 0.14
Table 3. Repeatability for Select Refinery Gas Components (% RSD for retention times and areas large valve oven temp 65 and 70 °C)