Volcanic ashes as a source for nitrated and oxygenated polycyclic aromatic hydrocarbon pollution

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Mass Spectrometry

Background:

• Polycyclic Aromatic Hydrocarbons (PAHs) are common environmental pollutants.
• Volcanic ash can potentially contain and distribute various chemical contaminants.
• Limited data exists on oxygenated and nitrated PAHs in volcanic ash.

Purpose of the Study:

• To develop a sensitive analytical method for quantifying oxygenated and nitrated PAHs in volcanic ash.
• To investigate the presence and distribution of these specific PAH compounds in volcanic ash samples.
• To identify novel environmental sources and pathways for PAH pollution.

Main Methods:

• Development of a novel dispersive solid-liquid microextraction (DSLME) technique.
• Coupling DSLME with ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) for sensitive detection.
• Optimization of DSLME parameters using chemometric tools.

Main Results:

• Achieved a linear calibration curve (r² > 0.994) for analytes from 0.01 to 100 μg g⁻¹.
• Obtained low limits of detection (14.6–56.0 pg g⁻¹) and high reproducibility (RSD < 8.1%).
• Demonstrated high recovery rates (94.2–100%) for the target compounds.

Conclusions:

• The developed DSLME-UHPLC-MS/MS method is highly sensitive and reproducible for analyzing PAHs in volcanic ash.
• Confirmed the presence of oxygenated and nitrated PAHs in volcanic ash at ultra-trace levels.
• Identified volcanic ash as a previously unrecognized source for the environmental distribution of these pollutants.