800 AMU. The gas chromatograph uses a flame ionization detector and a 45.7 x 0.32 cm stainless steel column packed with Molecular Sieve 13X, and a 12 meter x 0.2 mm capillary column glass packed with cross-linked methyl silicone. This capillary column serves as an interface between the packed columns and the mass spectrometer.

OFF-GASSING EVALUATION PROCEDURES

Place a sample material of known weight or surface area in a Parr Oxygen Bomb of known internal volume. Sample size will determine the final volume of the off-gassing chamber. Pre-clean the off-gassing chamber, and obtain blank background runs under conditions identical to the final material's off-gassing evaluation to ensure a zero hydrocarbon background.

Charge the chamber containing the sample material with high-purity (zero) air, normally 6800 cc ambient conditions. Charging pressure depends on the internal volume of the oxygen bomb. Allow the hydrocarbon content of the contained sample material to equilibrate with the zero air for four hours at 130°F, or another acceptable temperature, before accomplishing gas analysis (low ppm level) for specific and total hydrocarbons. Perform the gas analysis while the sample is still at the specified temperature.

Obtain gas analysis by using the following equipment: gas chromatographs equipped with flame ionization, thermal conductivity, and electron capture detectors, total hydrocarbon analyzer, total halogenated hydrocarbon analyzer, non-dispersive infrared analyzer, and a mass spectrometer/gas chromatograph. Use other instruments for special requirements.

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