Fast aerosol analysis by fourier transform imaging fluorescence microscopy.

Area of Science:

• Environmental Science
• Analytical Chemistry
• Spectroscopy

Background:

• Polycyclic aromatic hydrocarbons (PAHs) are significant air pollutants.
• Accurate and rapid detection of airborne PAHs is crucial for environmental monitoring.
• Existing methods for PAH analysis can be time-consuming or lack spatial resolution.

Purpose of the Study:

• To develop and validate a fast, sensitive imaging technique for analyzing airborne PAHs.
• To map and quantify PAH contamination on collected aerosol samples.
• To assess the potential for in situ and on-line monitoring of particulate PAHs.

Main Methods:

• Combining Fourier transform imaging spectroscopy with fluorescence microscopy and a cooled CCD detector.
• Collecting aerosols on glass fiber filters for analysis.
• Utilizing the technique to obtain a full fluorescence spectrum at each pixel for spatial mapping.
• Developing calibration plots for quantification.

Main Results:

• Achieved quantification limits in the range of 10 ng cm(-2) on filter (20 ng m(-3) in air) with 1-minute integration.
• Estimated an absolute detection limit as low as 0.25 pg on filter (0.5 pg m(-3) in air) with 1-minute integration.
• Demonstrated the method's capability for analyzing monocomponent contamination and simple mixtures.

Conclusions:

• Fourier transform imaging spectroscopy provides a powerful tool for rapid PAH analysis in aerosols.
• The method shows potential for in situ and on-line monitoring of airborne PAH contamination.
• Further automation could enable real-time environmental monitoring applications.