Study of Long-Term Compound Stability in Dual Sorbent Tubes

The primary means to assess spacecraft air quality during a mission, for crew health purposes, has been archival air samplers that are returned to the ground for analysis. One such sampler is the Dual Sorbent Tube (DST) developed in late 2003 by the Toxicology group at the Johnson Space Center. The DSTs provided a low mass, low-volume sampler that was compatible with the constraints of the Soyuz return vehicle.

The first set of DSTs, including positive control tubes, flew to the International Space Station (ISS) aboard Soyuz in January 2004 and they were returned in May 2004. The analytical recovery of compounds from the positive controls provides an indication of the stability of contaminants in the sampler. Analysis of the first returned set of positive controls revealed poor recoveries for several of the compounds. The low recoveries from the positive controls led to a study of compound stability on DSTs for long storage periods. This paper will provide the results of this study for a few key compounds.