Scion Instruments 456-GC User manual

Reference Manual
Greenhouse Gases
Analyzer
SCION Instruments HQ SCION Instruments NL BV
Suite 34, Livingston Business Centre, 4462, Goes,
Kirkton Road South, Livingston, Stanleyweg 4.
EH54 7FA, Scotland, UK. The Netherlands
Tel: [phone] Tel: [phone]
sales-e[email protected] [e-mail]
www.scioninstruments.com www.scioninstruments.com
Revised March 2019
© 2015 Scion Instruments

Scion Instruments
Scion Instruments Greenhouse Gases Analyzer Reference Manual Page: 2
SECTION CONTENTS
INTRODUCTION ..................................................................................................................................3
INSTRUMENT SPECIFICATIONS ...................................................................................................4
INSTALLATION OF COLUMNS, FLOW AND PRESSURE SETTINGS ...................................5
TUNING OF THE ECD CHANNEL ...................................................................................................6
TUNING OF THE TCD/FID CHANNEL............................................................................................7
OPERATION .........................................................................................................................................9
TROUBLE SHOOTING..................................................................................................................... 11
SYSTEM OVERVIEW ...................................................................................................................... 12

Scion Instruments
Scion Instruments Greenhouse Gases Analyzer Reference Manual Page: 3
INTRODUCTION
The Greenhouse Analyzer is an analytical tool principally developed for the
analysis of the greenhouse gasses CO2, CH4and N2O in Air.
The sample is simultaneously injected onto an ECD and a TCD/FID channel.
The N2O is analyzed on the ECD. CO2and CH4are analyzed on the TCD and
the FID.
The analyzer has two Injection/Backflush Valves. Both valves are equipped
with 500 µl sample loops.
On the ECD channel, the sample is injected on a Hayesep N pre-column
and a Hayesep D column. The N2O is flushed onto the second column; the
rest is backflushed to the vent. The ECD method can easily be adapted to
make the analysis of SF6possible. The Hayesep D column is able to
separate N2O from SF6.
On the TCD/FID channel, the sample is injected onto a Hayesep N pre-
column. The fraction containing Oxygen, Nitrogen, CO, Methane and CO2is
flushed onto a Porapak QS column, the rest is backflushed to the vent.
Injection of a sample is done by filling the sample loops by means of a
PWOC injector. The sample is then injected onto both channels. After
injection the sample path is flushed with helium to avoid carry over.
The instrument is tuned during Final Test to its proper settings. Do
not change any flow or pressure settings unless it is requested.

Scion Instruments
Scion Instruments Greenhouse Gases Analyzer Reference Manual Page: 4
INSTRUMENT SPECIFICATIONS
Every instrument is fully tested; the results of the tests, as well as the
methods used during these tests, are presented as part of this manual
(refer to section 1).
The Greenhouse Analyzer is equipped with Electronic Flow controls (EFC)
and a manual pressure regulator.
START UP
At initial START-UP as well as after a longer idle period,
follow the instructions below:
• Connect all the gases to the instrument.
• Switch the power on.
• Load the appropriate method.
• Check the flow settings.
• Condition the system as described in this manual.
• Do not make any changes to the methods.
• The system is ready for injections.
For a new system there is no need to do any flow measurement
or flow tuning before power-up. The instrument is tuned and
tested in our factory in Fremont.

Scion Instruments
Scion Instruments Greenhouse Gases Analyzer Reference Manual Page: 5
INSTALLATION OF COLUMNS, FLOW AND PRESSURE SETTINGS
Tuning of the analyzer is only necessary in case new columns are
installed or after flow or pressure settings have been changed
Make sure, the instrument is connected to the minimum gas supply
pressures as indicated in the pre-installation requirements (section 2 of this
manual).
For more detailed information concerning the configuration of the
instrument, refer to the drawing section (section 6 of this manual). The
factory drawing indicates which flow and pressure controllers are used. The
drawing also outlines the way the analyzer channel has been incorporated
into the gas chromatograph.
Regularly replace gas purification filters as well as eventual filters
mounted in the pneumatic compartment of the instrument.
Connect the columns according the flow schematics given in Section
6 and adjust the flows (if necessary) at an oven temperature of 50°C.
Check all connections for leakages.
It is advised to use an electronic leak detector, since 'Snoop' or
equivalent soap solutions contaminate the analytical flowpath
of your instrument. Take very good care not to create any dead
volume
Replacement columns:
SC15927 Haysep N 80/100, 0.5m * 1/8" Inert Steel
SC15925 Porapak QS 80/100, 1.0m * 1/8" UM
SC15926 Hayesep D, 2.0m * 1/8" Inert Steel

Scion Instruments
Scion Instruments Greenhouse Gases Analyzer Reference Manual Page: 6
TUNING OF THE ECD CHANNEL
•Set the temperature of the column oven at 50ºC.
•Turn off the make-up gas to the ECD.
•Switch V2 to the inject position and set the rear EFC-24 to give a flow of 20
ml/min, measured at the outlet of the ECD.
•Switch V2 back to the fill+backflush position and set the aux rear EFC-24 to
give a flow of 20 ml/min, again measured at the outlet of the ECD.
•Measure the flow at vent 2 and adjust the needle valve to give a flow of 20
ml/min.
•Set the rear DEFC-13 to 10 ml/min Ar/CH4.
•Program the system as described in the Operation section of this manual.
Tuning the backflush
Determine the backflush time with a sample containing low ppm N2O.
Initially run the sample with a backflush time of 5.0 minutes.
Reduce this backflush time until the N2O recovery starts decreasing. Set
the backflush to allow full recovery of the N2O.
The signal disturbance due to the valve switching should not influence the
N2O peak.
A representative chromatogram for an injection of lab air containing ± 320
ppb N2O is given in figure 1.
Figure 1: Example chromatogram for the ECD channel of the Greenhouse Analyzer
N2O

Scion Instruments
Scion Instruments Greenhouse Gases Analyzer Reference Manual Page: 7
TUNING OF THE TCD/FID CHANNEL
•Use Helium as carrier and Nitrogen as make-up gas.
•Turn of all FID flows. Switch V1 to the inject position and set the front EFC-
24 to give a flow of 20 ml/min, measured at the outlet of the FID.
•Switch V1 back to the fill+backflush position and adjust the aux front EFC-
24 to give a flow of 20 ml/min, again measured at the outlet of the FID.
•Measure the flow at vent 1 and adjust the needle valve to give a flow of 20
ml/min.
•Set the front DEFC-14 reference to give 20ml/min out of the reference of
the TCD, and set the DEFC-11 to give 10 ml/min make-up, 30 ml/min
Hydrogen en 300 ml/min Air.
•The front DEFC-14 make-up is used as sample line purge gas.
•Program the system as described in the Operation section of this manual.
Tuning the backflush
Determine the backflush time with a sample containing CO2and CH4.
Initially run the sample with a backflush time of 5.0 minutes.
Reduce this backflush time until the CO2recovery starts decreasing. Set
the backflush to allow full recovery of CO2and CH4.
The signal disturbance due to the valve switching should not influence
both peaks.
Note that CO2is analyzed on the TCD and Methane is analyzed on the FID.
A representative chromatogram of the TCD channel for an injection of lab
air containing ±385 ppm CO2and ±1775ppb CH4is shown in figure 2. The
FID channel is shown in figure 3.
98.587.576.565.554.543.532.521.510.5
45,000
40,000
35,000
30,000
25,000
20,000
15,000
10,000
5,000
0
-5,000
CO2
RT [min]
GC1002B032_Greenhouse_3_19_2010 8_53_44 AM_1_20.DATA [Front (TCD)]
µV
Figure 2: Example chromatogram for the TCD channel of the Greenhouse analyzer

Scion Instruments
Scion Instruments Greenhouse Gases Analyzer Reference Manual Page: 8
Figure 3: Example chromatogram for the FID channel of the Greenhouse analyzer
The system is now ready for conditioning
Run the method continuously overnight to condition all columns. Refer to
the 456-GC user manual for operating the Automation.
CH
4

Scion Instruments
Scion Instruments Greenhouse Gases Analyzer Reference Manual Page: 9
OPERATION
An operational method is preloaded in the instrument.
Listed below is an example method; settings determining the application
may be different.
Valve Oven:
Temperature: 50°C
Sample delivery:
V1 (IBV)
V2 (IBV)
V3 (EA)
Initial
-
-
-
0.01
-
-
+
1.00
+ + +
2.10
- + +
2.20
-
-
-
Front PWOC injector:
Temperature: 100°C
Flow /pressure:
Front EFC-24 (He)
Pressure (PSI)
Hold (min)
Initial:
14.0
10
Total flow: 60 ml/min
Aux Front EFC-24 (He)
Pressure (PSI)
Hold (min)
Initial:
18.0
10
Total flow: 60 ml/min
Rear EFC-24 (Ar/CH4)
Pressure (PSI)
Hold (min)
Initial:
21.0
10
Total flow: 60 ml/min
Aux Rear EFC-24 (Ar/CH4)
Pressure (PSI)
Hold (min)
Initial: 18.0 10
Total flow: 60 ml/min
Column oven:
Temp (ºC)
Rate (ºC/min)
Hold (min)
Total (min)
Initial 50 0 10.00 10.00

Scion Instruments
Scion Instruments Greenhouse Gases Analyzer Reference Manual Page: 10
Front detector (TCD):
Temperature: 200 ºC
Time constant: slow
Filament temp.: 280 ºC
Range: 0.05
Polarity: negative
Autozero: yes
DEFC-14
Reference flow: 20 ml/min
Make-up flow: 20 ml/min (sample line purge)
Middle detector (FID):
Temperature: 300 ºC
Time constant: slow
Range: 12
Autozero: yes
DEFC-11
Make-up (N2): 10 ml/min
Hydrogen: 30 ml/min
Air: 300 ml/min
Rear detector (ECD):
Temperature: 350 ºC
Time constant: slow
Cell current: Ar/CH4
Contact Potential: 300 mV
Range: 10
Autozero: yes
DEFC-13:
Makeup (Ar/CH4): 10 ml/min
Refer to section 1 for the actual method(s).
Never interrupt an analytical run. The complete cycle has to finish
The system has two sampling valves. Both valves inject simultaneous on
both channels

Scion Instruments
Scion Instruments Greenhouse Gases Analyzer Reference Manual Page: 11
TROUBLE SHOOTING.
For problems related to the basic hardware and electronics of the gas
chromatograph, as well as injectors and detectors, refer to the 456-GC user
manual.
In case of any analytical problem, it is always advised to record an analysis
using a reference sample. The result, including full details can be
submitted to your local Scion Instruments service department to judge
performance.
CONSUMABLES
Replacement columns:
SC15927 Haysep N 80/100, 0.5m * 1/8" Inert Steel
SC15925 Porapak QS 80/100, 1.0m * 1/8" UM
SC15926 Hayesep D, 2.0m * 1/8" Inert Steel

Scion Instruments
Scion Instruments Greenhouse Gases Analyzer Reference Manual Page: 12
System Overview
• NOTE 1: Sample injection bymeans of CTC Headspace autosampler
possible
SampleOUT
ECD
DEFC-13
rear
N2O +SF6
FID
DEFC-11
middle
TCDReference
TCD
DEFC-14
front
Carbon Dioxide Methane
Sampleline purge
Helium
*) TCD Make-Up
DEFC-14
Sample loop 500µL
EFC-24
front
Helium
PorapakQS
SC15925
PWOC
Vent-3
V-3
Vent-1
Sample loop 500µL
Hayesep D
SC15926
Vent-2
Restrictor tube:
0.80mx 1/16" x 0.25mm SS
EFC-24
Auxrear
Argon/Methane
EFC-24
rear
Argon/Methane
NV-1 NV-2
12
3
4
5
6
7
8
9
10
V - 1
12
3
4
5
6
7
8
9
10
V - 2
CP742552UM 1041 insert for HS sampling
TCD MakeUp
*)
EFC-24
Auxfront
Helium
Hayesep N
SC15927
All sample wetted tubing incl. sample
loop, plumbed with Inert Steel tubing
and Silcosteel coated fittings, where
applicable.
Hayesep N
SC15927