Development of a simple solvent-based pretreatment technique for rapid and accurate quantification of PAHs in...

Particulate matter (PM) is a major airborne pollutant whose toxicity is strongly influenced by its chemical composition. Among its components, polycyclic aromatic hydrocarbons (PAHs) are key toxic and carcinogenic organic compounds, making the rapid and accurate quantification of these compounds essential for establishing inhalation toxicity exposure conditions. However, existing PAH pretreatment protocols have been optimized for trace-level environmental monitoring and therefore rely on long extraction times and complex instrumentation, making them unsuitable for high-concentration PM samples required in toxicological studies. To overcome these methodological limitations, we developed and validated a simplified solvent extraction-based pretreatment method specifically designed for the rapid quantification of PAHs in PM used for inhalation toxicity assessment.

PM was generated through repeated propane combustion and quenching using a laboratory-scale soot generator, collected on Teflon filters, and extracted using a 1 min vortex-assisted solvent extraction with dichloromethane, hexane, or methanol. Spiking tests confirmed extraction efficiencies above 85 % across all solvents, with dichloromethane showing a mean of 97 % (benzo[a]pyrene = 96.1 %). Whereas hexane and methanol showed a decrease in performance with increasing PAH molecular weight, dichloromethane consistently maintained stable and high recovery across all analytes. Analytical repeatability was excellent for all solvents, yielding mean relative standard deviation values of approximately 2 % (ANOVA (two-way) p < 0.01). The entire pretreatment process was completed in 1 min, representing a substantial improvement in extraction speed and operational simplicity compared to conventional techniques.

This study establishes a rapid, reproducible, and purpose-built pretreatment method for quantifying PAHs in particulate matter under toxicity-testing conditions. The total pretreatment time is less than 5 min, including a 1 min vortex extraction, and dichloromethane achieves extraction efficiencies above 93.5 % with mean relative standard deviations of around 2 % across sixteen PAHs. These results demonstrate that the method provides both significantly improved extraction speed and high analytical accuracy for high-concentration PM samples. By enabling fast and reliable determination of PAHs in toxicity-relevant PM, the proposed approach offers a practical tool for enhancing consistency, throughput, and data quality in inhalation toxicity evaluations.