Increasing chemical coverage, accuracy, and reproducibility of the processing method for polar organic chemical integrative samplers

Despite their diffusion in research studies, passive samplers are rarely used in regulatory applications. To expand the employment of passive samplers in regulatory environmental studies, standardized procedures for processing each sampler type should be proposed and accepted, but currently, each study develops its own protocol based on previous knowledge and specific needs. In this work, six identical polar organic chemical integrative samplers in seawater were deployed to understand the importance of the sorbent transfer method prior to the elution step. A common "wet transfer" with ultra-pure water was compared to a less diffused "dry-transfer," assessing recoveries and matrix effects of 38 target compounds of emerging concern, including polar pesticides, recreational and food-related substances, pharmaceuticals, industrial additives, and ultra-violet (UV) filters. The dry-transfer procedure generally allowed better recoveries, especially for the more polar compounds, without affecting matrix effects (which remained in the range 40-130%). Along with the recovery assessment, the analysis of the non-spiked sorbent extracts revealed traces of many of the targeted emerging contaminants, quantifying perfluorooctanoic acid, UV-filters, carbamazepine, diclofenac, and triclosan. Furthermore, other compounds were found below their limits of quantitation. Ten analytes were detected only in the extracts of the dry-transferred passive samplers, highlighting the importance of applying this protocol, especially when dealing with polar compounds. This refined processing method, therefore, permits a more standardized and reproducible strategy, at the same time enlarging the set of analytes which could be detected and quantified.