Real-time detection of chemical compounds in dust particles using a Single-Particle Mass Spectrometer and its potential for safety applications

The global rise in mobility and trade implies growing challenges in detecting safety-related and hazardous substances during transport and handling. To cope with these challenges, advanced technological solutions and improved, real-time detection methods are demanded. The capability to detect unknown target substances is particularly crucial, considering e.g. the modifications made to circumvent regulations in designer drugs. This study focuses on the detection of safety-related substances in dust particles in real-time using single-particle mass spectrometry (SPMS). SPMS allows for the identification of chemical signatures of individual aerosol particles. After passing through an aerodynamic lens and a pair of laser-light barriers for sizing and timing, the particles are exposed to an intense UV laser pulse, which induces ion formation through laser desorption/ionization (LDI). Additional steps to enhance the analytic capabilities involve desorbing the particles at a weaker laser energy and triggering a process called Resonance-Enhanced-Multi-Photon-Ionization (REMPI). SPMS-REMPI exhibits high sensitivity and selectivity, enabling the detection of even trace amounts of substances. Our measurements performed with various drugs, narcotics, and explosives show characteristic mass spectrometric signatures, allowing for clear identification and characterization of target compounds. The successful application of SPMS for environmental aerosol analysis proves its capability for real-time detection of a large variety of safety-related substances with high throughput, offering a powerful profiling tool to improve safety and security in logistics.