Adapting AMDIS for autonomous spectral identification of hazardous compounds for ISS monitoring

The stand-alone vehicle cabin atmospheric monitor (VCAM) instrument was designed to provide an automated method of monitoring air quality within the International Space Station (ISS) via a miniaturized mass spectrometer and gas chromatograph system. The output of the device, a series of mass spectra as a function of time, is then processed via our implementation of the automated mass spectral deconvolution and identification system (AMDIS) method from the National Institute for Standards and Technology (NIST) to generate potential identification with reference to a known library of hazardous chemicals. In this paper we discuss the modifications required to the AMDIS method for autonomous in-flight operation as well as additions beyond the original method. In particular, the original AMDIS method contains numerous parameters that were intended to be adjusted by an operator during the analysis to reduce false positives and adjust sensitivity. We have instead implemented solution filtration based on elution time and discuss possible arbitration algorithms for close similar matches to provide the user with a more succinct, single-valued answer.