Various freezing and melting operations can be carried out on a vacuum line, so that pure CO₂ can be sealed into ampoules as a discrete gas sample for analysis in the MICADAS. The CO₂ is generated by offline combustion of organic compounds from the PFC in larger quartz glass ampoules at 940 ° C and in the presence of CuO. In a tube cracker located on the vacuum line, these ampoules can be broken and the resulting CO₂ collected on a trap cooled with liquid nitrogen. The water produced during combustion is previously frozen out in a trap cooled with a dry ice / ethanol slurry. Pressure gauges allow quantification of the amount of CO₂ produced.