Correlation of Mass Spectrometry Identified Bacterial Biomarkers From a Fielded Pyrolysis-Gas Chromatography-Ion Mobility Spectrometry Biodetector With the Microbiological Gram Stain Classification Scheme

摘要

A pyrolysis-gas chromatography-ion mobility spectrometry (Py-GC-IMS) briefcase system can detect and classify deliberately released bioaerosols in outdoor field scenarios. The bioaerosols include Gram-positive spores and Gram- negative bacteria, the MS-2 Escherichia coliphage virus, and ovalbumin (OV) protein species. However, the origin and structural identities of the pyrolyzate peaks observed in the GC-IMS dataspace, their microbiological information content, and taxonomic importance with respect to biodetection have not been determined. The present work interrogates the identities of the peaks by inserting a time-of-flight (TOF) mass spectrometry (MS) system in parallel with the IMS detector through a Tee connection in the GC module. Biological substances, producing ion mobility peaks from the pyrolysis of microorganisms, have been identified by their GC retention times, by matching their electron ionization mass spectra with authentic standards, and by the National Institute of Standards and Technology (NIST) mass spectral database.