I have run the stable carbon isotope composition of n-alkanes
standards (20ng/ul;n-C17 to n-C30)in GC-C-IRMS. I am using a Finnigan MAT
combustion furnace containing Cu, Ni, and Pt wires and maintained at a
temperature of 940 degree. I have some trouble with this kind of combustion
reactor since the offset between on-line and off-line was ~-0.5 to -1 permil
and the negative shift continued to increase gradually after 2 or 3 runs. I
was wondering if there is anyway to improve the furnace performace.(I
reoxidized the furnace @940 for ~20' everyday).
Any input would be greatly appreciated.
Thanks in advance,
Air Quality Research Branch
4905 Dufferin Street
Toronto, ON M3H 5T4
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