Speaker
Description
The contamination of water resources by organic pollutants represents a significant environmental challenge worldwide. Monitoring these pollutants is essential for assessing water quality and reducing environmental risks. In this work, silver nanoparticle (Ag NP) thin films were investigated as functional substrates for the extraction of organic pollutants from aqueous samples prior to chromatographic analysis.
The Ag NP thin films were deposited on polyester substrates and glass using a cost-effective bottom-up synthesis method1, yielding nanostructured surfaces with low porosity and a high density of active sites capable of interacting with organic molecules. The structural and morphological properties of the films were characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM), confirming the formation of nanostructured silver domains with a high surface area.
The Ag NP thin films deposited on polyester sheets were tested as potential passive samplers for organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) by spiking them with 22 OCPs and 7 PCBs and then desorbing them by extraction with 5% diethyl ether in hexane. Recoveries from 38 to 115% were obtained for OCPs and between 88 and 120% for PCBs. Further, when exposed to spiked aqueous solutions, they showed a higher affinity for retaining aromatic organochlorine compounds than alicyclic ones.
The Ag NP thin films were then exposed to surface water for one month and Ag NP on polyester sheets were found as more stable for further tests compared to ones on glass. During this exposure period, the films captured 10 target OCPs and PCB congeners. In addition, 51 other organic contaminants were detected: 14 PAHs, 13 fragrance-related compounds, 9 industrial and plasticizer-related compounds, 5 pyrethroids, 4 antioxidant additives, and two additional compounds (a UV filter and an OCP). 86% contained an aromatic ring, consistent with the higher retention of aromatic compounds observed in the laboratory affinity tests. The reusability of the Ag NP-coated polyester sheets was also evaluated over three exposure–desorption cycles, with no statistically significant differences among the cycles.
Results suggest that Ag NP thin films on polyester sheets show potential for application as passive samplers for monitoring aromatic organic compounds in water media.