Install a capillary column in theovenof theSRI GC.
TheASTMmethod suggests a12meter .32mm id
narrow-bore column coupledwitha2.5meter guard
columnbut permits theuseof any columnwhichex-
hibits acceptable resolutionof theglycerideanalytes.
For easeof use, SRI prefers a15meter fused silica
linedmetal capillary column commonly calledawide-
boreMXT column. The ideal columnhas a thin film
( .16micron thick ) anda temperature ratingof 380C
or higher )
This typeof column is
unbreakable
( unlikeplain
fused silica columns ) andallows the injection syringe
todeposit the sampledirectly into theboreof the col-
umn itself. This is important becauseheatedor split/
splitless injectors candiscriminateagainst highboiling
analytes like triglycerides. TheASTM6584method
specifies cool-on-column injection like that foundas
standardequipment onall SRI gas chromatographs
toavoidboilingpoint discrimination.
PerformingASTM6584 freeand total glycerin in
BioDiesel usinganSRI GasChromatograph
andPeakSimple software version3.67
SRI currently ( September 2008 ) uses the
RestekMXT-BiodieselTG column.
Restek part#562551-2731
ChrompackHT5 .32mm id fused silca coupled
with2.5meter .53mm idguard column. A1/16’”
stainless steel unionwithgraphite ferrules con-
nects theguard column to theanalytical column.
The26ga. syringeneedle fits inside the .53mm
column toaccomplisha cool on-column injection
as specified in themethod.
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