Young-Su Jeong

Rapid detection of Bacillus spore aerosol particles by direct in situ analysis using MALDI-TOF mass spectrometry

Accurate and rapid analytical methods are essential for the detection and identification of biological warfare agents (BWA). Although various studies have investigated the use of MALDI‐TOF MS for bacterial classification, only a few studies have examined the applicability of method for the identification of BWAs. This study aimed to generate, collect and analyse Bacillus spore aerosol particles of 2–10 μm, the optimal size of a BWA. Bacillus spore aerosol particles of 2–10 μm were rapidly analysed using direct in situ MALDI‐TOF MS without pretreatment processes. A mass spectrum of Bacillus spore aerosol particles was successfully detected. For real‐time detection and identification, a mass spectral database of Bacillus spores was constructed, and an algorithm was developed and applied. Bacillus spore particles were rapidly detected and identified by MS, which can be used for the detection and inspection of BWAs.

The Effect of Inkjet Operating Parameters on the Size Control of Aerosol Particles

We investigated the effect of inkjet operating parameters on the size control of aerosol particles. Droplets with agglomerates of polystyrene latex particles were generated from an inkjet nozzle and continuously dried up at the temperature of 38°C. When droplets have the size range of 30 to 70 μm in diameter, aerosol particles with the size range of 3.5 to 7.1 μm were generated after the drying process. We controlled the particle size easily within a factor of two by adjusting rising/falling time and voltages of an actuating waveform. Generated particles were shown to have a narrow particle size distribution. Thus, the particle concentration of aqueous suspension does not need to be adjusted precisely in order to control the size of generated aerosol particles. Copyright

Deep UV Raman Spectroscopic Study for the Standoff Detection of Chemical Warfare Agents from the Agent-Contaminated Ground Surface

Short-range detection of chemical agents deposited on ground surface using a standoff Raman system employing a pulsed laser at 248 nm is described. Mounted in a vehicle such as an NBC reconnaissance vehicle, the system is protected against toxic chemicals. As most chemicals including chemical warfare agents have unique Raman spectra, the spectra can be used for detecting toxic chemicals contaminated on the ground. This article describes the design of the Raman spectroscopic system and its performance on several chemicals contaminated on asphalt, concrete, sand, etc.