A Chemical and Biological Portable Mass Spectrometer (CB-pMS) with Automated Sampling and Hybrid Ionization for Online Detection of Bioaerosols and VOCs.

The escalating threat of airborne chemical and biological pollutants demands real-time monitoring technologies capable of simultaneously detecting both classes of contaminants. Conventional analytical methods are frequently constrained by slow response times, high labor requirements, or confinement to laboratory settings. Here, we present a field-deployable instrument, designated as the CB-pMS (chemical and biological portable mass spectrometer), for the automated online detection of volatile organic compounds (VOCs) and bioaerosols. The instrument incorporates an orthogonal hybrid ionization source combining vacuum ultraviolet photoionization (UV-PI) and electrospray ionization (ESI) paired with a pyrolysis interface, enabling noninterfering operation and synergistic ionization of VOCs and airborne microorganisms. The CB-pMS achieves detection limits of 1 ng/mL for liquid-phase hypaconitine and 10 ppbv for gas-phase dimethyl methyl phosphonate (DMMP), exhibiting excellent linearity (R2 > 0.99) and MS/MS confirmation capability for analyte identification. In a dynamic wind tunnel experiment designed to simulate realistic environmental conditions, the instrument successfully conducted automated sequential analysis of benzene, toluene, xylene, and airborne Bacillus subtilis. With compact dimensions (48 cm × 34 cm × 56 cm) and a weight of 42 kg, the CB-pMS represents a significant advancement toward field-deployable, comprehensive monitoring of airborne chemical and biological threats for environmental surveillance, industrial hygiene, and homeland security applications.