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GC & Precision - Getting the Right Information
Acquisition method, Agilent GC, Calculating split and splitless carrier gas flows
Precision
UK English
Peak Scientific
private
How to get acquisition method information from Agilent and Shimadzu systems. How to interpret method information. How to calculate split and splitless inlet flows.
GC - Getting the right information
Author: Ed Connor Date / Rev: June 2015
Confidential, unpublished property of Peak Scientific Ltd. Do not duplicate or distribute. Use and distribution limited solely to authorized personnel. © 2015 Peak Scientific Ltd.
Ask for a copy of the acquisition method – if unavailable, ask for the key gas and flow information
If no acquisition method available the customer needs to provide carrier total flow (column flow + split flow + purge flow) and detector flow information
What carrier gas is being used?
H2 or N2
What is the total carrier gas flow being used?
X 1.25 if converting to hydrogen
He
Is the customer converting to N2 or H2?
YES
NO
What detectors are being used?
Calculate total carrier flow required for all GCs
Calculate flow rates of hydrogen, Zero air and nitrogen for flame, flame support and make-up gas
*If customer was using helium carrier, have they considered using nitrogen for make-up gas? *For ECD detectors, quote Trace Nitrogen
Carrier & Detector Gas Options
FID He Carrier gases H2 N2 H2 Combustion gases Zero Air 300-500 60-100 60
Trace
FPD
NPD
ECD
TCD
SCD
MSD
*
30-50
50-75
2-5
40-100
40-100
Makeup gas
N2
10-40 Reference gas
H2
60
5-10
60
10 - 75
N2
* Can be used, but check with Product management before quoting
Confidential, unpublished property of Peak Scientific Ltd. Do not duplicate or distribute. Use and distribution limited solel y to authorized personnel. © 2015 Peak Scientific Ltd.
Acquisition method
Confidential, unpublished property of Peak Scientific Ltd. Do not duplicate or distribute. Use and distribution limited solel y to authorized personnel. © 2015 Peak Scientific Ltd.
Acquisition method
Confidential, unpublished property of Peak Scientific Ltd. Do not duplicate or distribute. Use and distribution limited solel y to authorized personnel. © 2015 Peak Scientific Ltd.
Acquisition method
Confidential, unpublished property of Peak Scientific Ltd. Do not duplicate or distribute. Use and distribution limited solel y to authorized personnel. © 2015 Peak Scientific Ltd.
Agilent Example 1
Confidential, unpublished property of Peak Scientific Ltd. Do not duplicate or distribute. Use and distribution limited solel y to authorized personnel. © 2015 Peak Scientific Ltd.
Agilent Example 2
Confidential, unpublished property of Peak Scientific Ltd. Do not duplicate or distribute. Use and distribution limited solel y to authorized personnel. © 2015 Peak Scientific Ltd.
Shimadzu systems
Confidential, unpublished property of Peak Scientific Ltd. Do not duplicate or distribute. Use and distribution limited solel y to authorized personnel. © 2015 Peak Scientific Ltd.
Carrier Gas Calculations
The aim of calculating the carrier gas flow rate is to find the ‘total flow’ of the carrier gas. Knowing the total flow allows us to recommend the correct generator(s) to support the GC Most GCs use a split/splitless injector The calculation of flow rates differs depending on whether the method uses split injection or splitless injection
Confidential, unpublished property of Peak Scientific Ltd. Do not duplicate or distribute. Use and distribution limited solel y to authorized personnel. © 2015 Peak Scientific Ltd.
Split injection calculation
Confidential, unpublished property of Peak Scientific Ltd. Do not duplicate or distribute. Use and distribution limited solel y to authorized personnel. © 2015 Peak Scientific Ltd.
Splitless injection calculation
Confidential, unpublished property of Peak Scientific Ltd. Do not duplicate or distribute. Use and distribution limited solel y to authorized personnel. © 2015 Peak Scientific Ltd.