Sustainable on-site retention of antidepressants from wastewater using a recyclable 3D-printed SPE device followed by UHPLC-FL detection

Antidepressants (ATDs) are widely used to treat mental health disorders such as depression, anxiety, and insomnia, resulting in their increasing occurrence in wastewater treatment plants (WWTPs). In this study, a 3D-printed device specially designed to promote its easy adaptation to the analysis of samples in a wide range of concentrations, has been coated with solid-phase extraction (SPE) Oasis MCX resin for the extraction and preconcentration of ATDs, followed by ultrahigh-performance liquid chromatography with fluorescence detection (UHPLC–FL). The developed methodology targeted venlafaxine (VEN), citalopram (CIT), fluoxetine (FLX), and O-desmethylvenlafaxine (ODV), the main metabolite of VEN. The 3D-printed device is operated with a peristaltic pump, enabling both the on-site retention, avoiding the transport and conservation of large sample volumes and the loss of the analytes of interest, as well as the elution in the laboratory. In addition, a mass calibration was performed to give versatility to the method, since it allows the analyst to adequate the volume in terms of the sample concentration. High performance of the method was confirmed by low detection limits ranging from 0.11 to 0.20 μg and enrichment factors exceeding 618. Recovery rates in wastewater samples were between 79 and 105% for all analytes, and no sample pretreatment was required. Although the greenness assessment score was moderate (0.49 via AGREEprep), the device can be reused up to eight times without losing efficiency. Besides, recycling the material to manufacture new devices was explored as a proof-of-concept strategy to enhance the long-term sustainability of the method.