A Thermo-Cavitation Method to Determine Organochlorine Pesticides in Gas and Particle Phases Collected in Polyurethane Foam Used in Passive Air Samplers

Persistent organic pollutants (POPs) are globally dispersed substances considered to have adverse effects on health and ecosystems. Organochlorine pesticides (OCPs) are POPs. OCPs can be collected from the air by passive samplers using polyurethane foam (PUF). POPs in PUF are generally extracted by Soxhlet, considered as reference extraction method. We offer a different methodology approach to extract 16 OCPs from the PUF. This technology extracts, filters, collects the sample and evaporates the solvent, without sample transfer. It is a modification of the ultrasound-assisted extraction micro-scale cell (M-UAE-MSC) previously patented by our group. A full factorial experimental design (2³ centred) was used to optimise the extraction conditions. The most desirable conditions were 50 °C, 40% ultrasound potency and 20-min extraction time, two extractions. OCP recoveries ranged from 67 to 110%. OCP recoveries were equivalent by M-UAE-MSC and Soxhlet techniques. The method was not suitable for five OCPs, and further refinement is needed. Method linearity (r²) was ≥ 0.98. Limits of detection were observed between 1.2 and 4.6 ng PUF⁻¹, while limits of quantification were found between 3.9 and 15.2 ng PUF⁻¹. The method was applied to determine OCPs collected by PUF passive samplers in Mexico. Endosulfan I was the OCP most frequently observed. The M-UAE-MSC optimised extraction conditions, decreased the extraction time from several hours to less than 1 h and reduced three times the solvent consumption with respect to Soxhlet. This afforded a decrease in the waste generation and a reduction in the OCP-extraction cost up to 80%. The results of this study reveal an efficient and consistent procedure, as well as a simpler, faster, cost-saving and more environmentally friendly method to determine OCPs collected by PUF in passive samplers compared to Soxhlet extraction.