A novel approach for determining organochlorine pesticides in atmospheric samples collected on polyurethane foam based on thermal desorption and resorption processes: design, validation, and application

Organochlorine pesticides (OCPs) in the air represent a risk to human health and other organisms. Their determination must involve methodologies that do not generate additional pollutants. This study proposes an alternative to extract OCPs in atmospheric aerosol collected in polyurethane foam (PUF) and passive samplers (PAS) by a thermal desorption/vapor resorption extraction system (THEVESys). Optimised sample treatment conditions were based on a 2³ full factorial design of experiments (DoE) with a centre point. Variables positively influenced desirability, but not independently; triple interaction was critical. The efficiency of the method for 14 out of 20 OCPs falls within the acceptable range of 60-120%. Precision, assessed as the relative standard deviation, was <20% for 17 OCPs. Linearity (r²) was ≥0.998. Intermolecular forces played a more important role than the relative volatility of OCPs, related to the octanol-air partition coefficient (log K_OA). Sensitivities were 1.2 to 3.4 times higher for OCPs without matrix effects than for those with matrix effects, due to ion suppression, or lower mass transfer from the injector to the mass spectrometer. Therefore, correction functions were proposed to quantify OCPs extracted with THEVESys. THEVESys was compared with a previously validated methodology, yielding similar results. Our methodology scored 0.6/1.0 on the AGREE metric, making it an environmentally friendly option for determining OCPs in PUF-PAS. Finally, THEVESys was tested on a few atmospheric samples from central Mexico, and only α-hexachlorocyclohexane was detected. The concentrations were consistent with those determined using the methodology previously validated.