This experiment was a drilled solid sample experiment, designated
CB OD2. It was the first step of an opportunistic derivatization (OD)
experiment using a doggie-bag sample of the Cumberland drill hole
material. It took advantage of the presence of the derivatization
reagent, N-methyl-N-tert-butyldimethylsilyl-trifluoroacetamide
(MTBSTFA), which had been adsorbing onto the sample since it was
loaded into the pyrolysis cup several months previously. The
experiment was executed in two steps. In OD1, the oven was heated
to 250 deg C for removal of O2 from oxychlorine compounds. Gases
evolved at oven T up to 125 deg C were collected on the SAM
trap for later analysis by the GC. After OD1, the pyrolysis cup was
returned to the sample manipulation system for 48 hours to allow
MTBSTFA to readsorb onto the sample residue. In the second step, or
OD2, the oven was heated to 900 deg C and gas was collected on the
SAM trap for GC analysis throughout the entire temperature ramp.
For estimation of abundances of volatile compounds detected in EGA, the
background was subtracted as a constant value, either at the start or
end of the run or before major peaks. An exception to this was CO2,
which was modeled with a downward-trending background throughout the
run. Uncertainties in abundances, deriving from statistical noise,
background subtraction, calibration factors, assumptions regarding
ionization cross-sections for the relevant compounds, and isobaric
interferences, are estimated at 10-20% of the values.