GC ACCESSORIES
Methanizer
TheMethanizeroptionenables theFlameIonizationDetector todetect low levelsofCOandCO
2
. It is
installedas the removable jet inaspecialFIDdetectorassembly. TheMethanizer / jetdelivers thecolumn
effluentmixedwithhydrogen to theFIDdetector. TheMethanizer ispackedwithanickelcatalystpowderon
glasswoolsecuredwith twofrits. Duringanalysis, theMethanizer isheated to380
o
Cwith theFIDdetector
body. WhenthecolumneffluentmixeswiththeFIDhydrogensupplyandpassesthroughtheMethanizer,CO
andCO
2
areconverted tomethane. Since theconversionofCOandCO
2
tomethaneoccursafter thesample
compoundshavepassedthroughthecolumn, theirretentiontimesareunchanged. Hydrocarbonspassthrough
theMethanizerunaffected. ThespecialMethanizerFIDdetectorassemblyoperates like the regularFID
detector,except that theFID temperaturemustbeset to380
o
C. Due to thechemical relationshipbetween
nickelandsulfur, theMethanizercanbepoisonedby largequantitiesofsulfurgas.
Methanizer-equippedFIDDetector
Expected Performance
ThefollowingchromatogramwasproducedbyanSRIMultipleGasAnalyzer#1equippedwithaMethanizer.
Column
effluent
Hydrogen
supply
Air
supply
Ceramic
ignitor
Collector
electrode
Collector lead
toamplifier
Viewport capnut
Nickel
catalyst
Thermostatted
heaterblock
andcover
Exhaust
Results:
Component
Retention Area
O2/N2
1.650 4731.2140
Methane
3.866 2008.6000
Ethane
7.316 3854.7300
CO2asMethane 9.250 3142.1040
Propane
12.083 5379.8755
Butane
15.533 7326.4440
Pentane
18.333 9136.3340
Hexane
21.900 10408.3160
Total
45987.6175
Sample:41cc roomair+15cc1000ppmC
1
-
C
6
injected into the 1mL sample loop =
250ppmCO
2
andC
1
-C
6
