Detector for particulate polycyclic aromatic hydrocarbons in water

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Water Quality Monitoring

Background:

• Most polycyclic aromatic hydrocarbons (PAHs) in water exist in particulate form.
• Existing optical detectors struggle with sampling solid-phase PAHs.
• Accurate quantification of particulate PAHs is crucial for environmental assessment.

Purpose of the Study:

• To develop a novel setup for direct sampling and quantification of suspended particulate PAHs in water.
• To evaluate the performance of two sampling modes: bulk and surface sampling.
• To assess the potential for analyzing PAH mixtures in environmental samples.

Main Methods:

• Utilized a polymeric film capable of dissolving PAH particulates, coupled with a laser-induced fluorescence probe.
• Investigated bulk sampling (probe immersion) and surface sampling (film on water surface).
• Studied the effects of co-existing particulates and the feasibility of analyzing PAH mixtures.

Main Results:

• Surface sampling demonstrated higher sensitivity compared to bulk sampling, though it was diffusion-limited.
• Achieved linear calibration plots for quantification across a wide concentration range.
• Detection limits were in the parts per billion (ppb) range, with potential for improvement.
• Observed minimal interference from other waterborne particulates.

Conclusions:

• The developed setup offers a viable method for direct sampling and quantification of particulate PAHs.
• Surface sampling is more sensitive but requires optimization to overcome diffusion limitations.
• Multivariate analysis is necessary for the accurate analysis of complex PAH mixtures.