A sampling platform incorporating 3D-printed paddles-stirrers coated with metal-organic framework MIL-100(Fe) for in-situ extraction of phenolic pollutants in biodigester supernatant and wastewater effluent samples

Abstract

In this work, a portable paddle stirrer platform for solid-phase extraction of chlorophenols, p-nitrophenol, and bisphenol A is presented. These compounds are important environmental pollutants and toxic inhibitors of the anaerobic treatment of wastewater. The platform integrates 3D-printed paddle stirrers coated with the metal-organic framework MIL-100(Fe), which is prepared in 10 minutes using a green microwave-assisted synthesis. This coated stirrer serves as an adsorbent for the preconcentration of phenols. The device is assembled with an electric motor that agitates the sample in a sample container. The sampler can be used for in-situ extraction of the analytes, eliminating the need for transporting samples to the laboratory. The analytes are eluted through ultrasonic desorption before analysis by HPLC-DAD. An exhaustive study of the stirring and extraction parameters was conducted. Under optimum conditions, the detection limits ranged from 0.3 to 1.7 μg L-1, and the precision, expressed as the relative standard deviation, showed intraday and interday ranges of 1.2% to 5.1% and 4.5% to 6.8%, respectively. The accuracy was evaluated using spiked samples of wastewater effluent and biodigester supernatant, and it provided relative recoveries in the range of 91.5% to 108.5%.