We propose the use of tunable-laser PTI (TL-PTI) as a self-calibrating reference technique for quantifying β_abn. In TL-PTI, a wavelength-tunable laser is used to quantify the narrow absorption lines of a gas via direct absorption spectroscopy, providing a reference β_abn,ref in units of Mm^-1. The A-band absorption lines of ambient oxygen at about 760 nm provide a convenient reference. The PTI signal is then calibrated to this β_abn,ref. This gas-PTI signal can then be “switched off” by tuning the laser wavelength away from the absorption lines, so that only particulate PTI signals remain in the background-subtracted signal.

A novel aerosol collection method using suspended liquid films and electrostatic precipitation has been developed to enhance airborne particle detection, including pathogens. The technique employs strong electrostatic fields to capture particles into a liquid film, increasing particle concentration and reducing system losses. An optimised liquid formulation was tested in a chamber with aerosolised microspheres, showing enhanced collection performance with increasing electrostatic field strength. Results suggest that dielectrophoretic forces primarily drive the improvement, with potential applications for sampling low concentrations and recovering viable bioaerosols. The technique shows promise for advancing aerosol sampling methods in various fields.

Illicit substances pose a significant threat to EU public health and security. Conventional surface sampling methods have limitations, prompting a new approach: collecting airborne fractions using an aerosol device. Integrating this with a novel detection device enables analysis via spectroscopy and mass spectrometry, providing a complete characterization. This innovative method enhances detection of illicit substances, streamlines border security processes, and reduces risks associated with handling hazardous materials. It offers a more effective and efficient solution for pre-screening at critical checkpoints, such as customs, airports, and postal services, improving overall security and public safety.

Nanoparticles exhibit complex shapes, influencing properties like bioavailability, toxicity, and reaction kinetics, necessitating detailed size and shape characterization. Conventional methods measure equivalent sizes (e.g., aerodynamic or mobility equivalent diameters) using devices like DMA or APS. Comprehensive analysis requires multidimensional distributions of particle properties. The Centrifugal Differential Mobility Analyzer (CDMA) addresses this by simultaneously classifying particles based on electric and centrifugal fields. It enables two-dimensional property distribution measurements of aerodynamic and mobility equivalent diameters. Results show robust measurements of silver aerosols, highlighting shape factors and multidimensional particle characterization.

The Aerosol InfraRed Monitor (AIRMon) is a novel instrument for near real-time chemical characterization of particulate matter using IR spectroscopy. The AIRMon integrates patented aerosol collection with automated IR measurements, providing quantitative data on organic functional groups and inorganic components. It utilizes an IR-transparent substrate to overcome previous limitations, granting access to previously unavailable spectral regions. This contribution presents detailed calibration analyses and compares AIRMon measurements with other established techniques. Field data from two ACTRIS sites and laboratory measurements of biomass burning emissions are discussed, demonstrating the AIRMon potential for improved air quality monitoring in real-world settings.

Atmospheric trace gases exhibit diverse chemical properties that challenge comprehensive analysis. We introduce Multi-Pressure Chemical Ionization Mass Spectrometry (MPCIMS), integrating high‐ and low‐pressure ionization in a single instrument to quantify volatile precursors and their oxidation products from one gas stream. By incorporating uronium as a reagent, MPCIMS achieves ultra‐sensitive, humidity‐resilient ionization—making uronium a promising positive mode CIMS reagent of choice. Demonstrated in laboratory experiments with a‑pinene, our approach captures the full spectrum from volatile precursors to highly functionalized products, offering comprehensive sensitivity and simplified operation for gas phase measurements to study secondary organic aerosol formation.