Chemical Analysis, Life Sciences, and Diagnostics | Agilent - … · 2016-09-04 · ISCC 2014...
1
ISCC 2014 Poster # K.81 THE APPLICATION of PLOT COLUMNS FOR THE ANALYSIS OF LIGHT HYDROCARBONS USING FLOW MODULATED COMPREHENSIVE GCXGC Shifen Xu 1 , Jim Luong 2 , Taylor Hayward 2 , Juan Aybar 3 , and Roger Firor 4 Introduction Flow Modulation GCXGC and the Analysis of Light Hydrocarbons Experimental Instrument Agilent 7890B with 2nd Generation Flow Modulator Inlet Split/Splitless Detector FID, 100 Hz Typical Oven Program 40 °C ( 0 min.) to 250 °C @ 10 °C/min Primary Column Flow, D1 0.8 mL/min Secondary Column Flow, D2 22 to 35 mL/min Mode Constant Flow Carrier Hydrogen Split Ratio 25 – 150 to 1 Modulation Period 1.5 s – 3.0 s Inject Time 0.12 s to 0.17 s Columns See column sets Results and Discussion Summary Modulator Operation Pulsed flow modulation (PFM) offers advantages over thermal modulation for implementation of comprehensive GCxGC Strengths: • Does not require cryogen • Simple to construct (connection fittings, three-way micro fast response gas switching valve, a modulation timing board) • Ideal for fast moving molecules • Methane, permanent gases, and light hydrocarbons can be modulated which is not possible with thermal focusing systems • Compatible with PLOT columns in D1 and D2 Reverse Sampling: • This second generation flow modulator adds an additional port to the CFT device to accommodate a channel fill restrictor. This implements a reverse direction flow in the collection channel when sampling to D2 The intent if this work is not to show extremely complex separations but to show the basic building blocks and combinations that can be used to address light hydrocarbon analysis using flow modulation Fast moving molecules, light hydrocarbons, light chlorinated hydrocarbons, and oxygenated compounds can all be analyzed with flow modulated GCXGC Provides an easy to interpret visual image of the sample for quick action if needed in QA or process environments Complementary technique to classical rotary valve multi-column gas analysis Compatibility with adsorption chromatography [PLOT columns] shown Bonding technology cuts down on particle shedding, reducing need for particle traps In general higher D2 flow ( 30 mL/min) and longer sampling times (0.17 s) improves modulation Provides a “visual map” of light process streams for rapid interpretation Since the collection channel is fixed … Flow rates should not exceed 1 ml/min in D1 D2 column flow is typically 20 to 30 mL/min dependent on the column set, D2 retention factor, D1 flow The sampling channel is flushed or injected into the D2 column in the reverse flow direction from filling. This leads to better modulated peak shapes and higher sample capacity 1D modulated chromatogram of light gases C1 –C6, 40 °C to 250 °C @ 15 °C/min D2 flow: 22 mL/min ethane ethane ethylene acetylene D1 - PoraBOND Q, D2 – VF-WAXms D1 – Rtx-Al 2 O 3, D2 – VF-WAXms D1 - CP-Silica PLOT, D2 – VF-WAXms C1-C6, 40 °C to 250 °C @ 25 °C/min D2 flow: 35 mL/min Typical hydrocarbons and aromatics in ethylene process Period 3.0 s, Sample 0.12 s Period 3.0 s, Sample 0.17 s D1 : 22 psi, D2: 17 psi, D2 flow 22 mL/min D1: 22 psi, D2: 19 psi, D2 flow 25 mL/min Restrictor, Monitor FID FID C1 C2 C3 C4 C5 C6 C6 40 °C ( 2 min.) to 250 °C @ 25 °C/min, D2: 30 mL/min 25 °C/min, D2: 30 mL/min, sample time: 0.17 s C1 – C6 & Alcohol Mix 25 °C/min, D2: 30 mL/min, sample time: 0.17 s Silica Plot: 1 meter, 40 °C (2 min) to 250 °C @ 25 °C/min D2: 22mL/min, modulation: 2.0 s, restrictor 0.5 m x .10 mm Silica Plot: 1 meter, 40 °C (2 min) to 250 °C @ 25 °C/min D2: 35mL/min, modulation: 1.5 s, restrictor 0.5 m x .10 mm Settings that need to be optimized for any given column set include: restrictor dimensions, modulation period, sampling time, and D2 flow rates. Some examples of modulated chromatograms are shown below using the Silica Plot as the D1 column. Longer sampling times improve modulation Higher D2 flow rates and sampling time improves performance Alkane/alkene pairs 1. Agilent Technologies, 412 Ying Lun Road, 200131 Shanghai, China 2. Dow Chemical Canada, Highway 15, PO Bag 16 Fort Saskatchewan, Canada 3. Agilent Technologies , Carretera Nacional VI, Km 18.2, 28232 Las Rozas, Spain 4. Agilent Technologies, 2850 Centerville Rd, Wilmington DE, 19808 Sampling flow direction Monitor FID Monitor FID Higher D2 flow improves modulation C1-C2s C3s C4s C5s C6s Benzene Toluene C6 Process mix 30 m x 0.25 mm x 0.4 um C5 C4 C3 C6 PLOT Columns in D1 PoraBOND Q Al 2 O 3 MAPD CP-Silica PLOT Wax Column in D2 VF-WAXms 5 m x 0.25 mm x 1.0 um Column Sets Investigated
Transcript of Chemical Analysis, Life Sciences, and Diagnostics | Agilent - … · 2016-09-04 · ISCC 2014...
ISCC 2014
Poster # K.81
THE APPLICATION of PLOT COLUMNS FOR THE ANALYSIS OF LIGHT HYDROCARBONS USING FLOW MODULATED COMPREHENSIVE GCXGC
Shifen Xu 1, Jim Luong 2, Taylor Hayward 2, Juan Aybar 3, and Roger Firor 4
Introduction
Flow Modulation GCXGC and the Analysis of Light Hydrocarbons
Experimental
Instrument Agilent 7890B with 2nd Generation Flow Modulator
Inlet Split/Splitless
Detector FID, 100 Hz
Typical Oven Program 40 °C ( 0 min.) to 250 °C @ 10 °C/min
Primary Column Flow, D1 0.8 mL/min
Secondary Column Flow, D2 22 to 35 mL/min
Mode Constant Flow
Carrier Hydrogen
Split Ratio 25 – 150 to 1
Modulation Period 1.5 s – 3.0 s
Inject Time 0.12 s to 0.17 s
Columns See column sets
Results and Discussion
Summary
Modulator Operation
Pulsed flow modulation (PFM) offers advantages over thermal modulation for implementation of comprehensive GCxGC Strengths:
• Does not require cryogen • Simple to construct (connection fittings, three-way micro fast response gas switching valve, a
modulation timing board) • Ideal for fast moving molecules • Methane, permanent gases, and light hydrocarbons can be modulated which is not possible with
thermal focusing systems • Compatible with PLOT columns in D1 and D2
Reverse Sampling: • This second generation flow modulator adds an additional port to the CFT device to accommodate a
channel fill restrictor. This implements a reverse direction flow in the collection channel when sampling to D2
The intent if this work is not to show extremely complex separations but to show the basic building blocks and combinations that can be used to address light hydrocarbon analysis using flow modulation
Fast moving molecules, light hydrocarbons, light chlorinated hydrocarbons, and oxygenated compounds can all be analyzed with flow modulated GCXGC
Provides an easy to interpret visual image of the sample for quick action if needed in QA or process environments
Complementary technique to classical rotary valve multi-column gas analysis
Compatibility with adsorption chromatography [PLOT columns] shown
Bonding technology cuts down on particle shedding, reducing need for particle
traps
In general higher D2 flow ( 30 mL/min) and longer sampling times (0.17 s) improves modulation
Provides a “visual map” of light process streams for rapid interpretation
Since the collection channel is fixed … Flow rates should not exceed 1 ml/min in D1 D2 column flow is typically 20 to 30 mL/min dependent on the column set, D2 retention factor, D1 flow The sampling channel is flushed or injected into the D2 column in the reverse flow direction from filling. This leads to better modulated peak shapes and higher sample capacity
1D modulated chromatogram of light gases
C1 –C6, 40 °C to 250 °C @ 15 °C/min D2 flow: 22 mL/min
ethane
ethane
ethylene
acetylene
D1 - PoraBOND Q, D2 – VF-WAXms
D1 – Rtx-Al2O3, D2 – VF-WAXms
D1 - CP-Silica PLOT, D2 – VF-WAXms
C1-C6, 40 °C to 250 °C @ 25 °C/min D2 flow: 35 mL/min
Typical hydrocarbons and aromatics in ethylene process
Period 3.0 s, Sample 0.12 s Period 3.0 s, Sample 0.17 s
D1 : 22 psi, D2: 17 psi, D2 flow 22 mL/min D1: 22 psi, D2: 19 psi, D2 flow 25 mL/min
Restrictor, Monitor FID
FID C1 C2
C3
C4
C5
C6 C6
40 °C ( 2 min.) to 250 °C @ 25 °C/min, D2: 30 mL/min
25 °C/min, D2: 30 mL/min, sample time: 0.17 s C1 – C6 & Alcohol Mix
25 °C/min, D2: 30 mL/min, sample time: 0.17 s
Silica Plot: 1 meter, 40 °C (2 min) to 250 °C @ 25 °C/min D2: 22mL/min, modulation: 2.0 s, restrictor 0.5 m x .10 mm
Silica Plot: 1 meter, 40 °C (2 min) to 250 °C @ 25 °C/min D2: 35mL/min, modulation: 1.5 s, restrictor 0.5 m x .10 mm
Settings that need to be optimized for any given column set include: restrictor dimensions, modulation period, sampling time, and D2 flow rates. Some examples of modulated chromatograms are shown below using the Silica Plot as the D1 column.
Longer sampling times improve modulation
Higher D2 flow rates and sampling time improves performance
Alkane/alkene pairs
1. Agilent Technologies, 412 Ying Lun Road, 200131 Shanghai, China 2. Dow Chemical Canada, Highway 15, PO Bag 16 Fort Saskatchewan, Canada 3. Agilent Technologies , Carretera Nacional VI, Km 18.2, 28232 Las Rozas, Spain 4. Agilent Technologies, 2850 Centerville Rd, Wilmington DE, 19808
Sampling flow direction
Monitor FID
Monitor FID
Higher D2 flow improves modulation
C1-C2s
C3s
C4s
C5s
C6s
Benzene Toluene
C6
Process mix
30 m x 0.25 mm x 0.4 um
C5
C4
C3
C6
PLOT Columns in D1
PoraBOND Q Al2O3 MAPD CP-Silica PLOT
Wax Column in D2 VF-WAXms 5 m x 0.25 mm x 1.0 um
Column Sets Investigated
