In-situ simultaneous extraction of non-steroidal anti-inflammatory drugs from wastewater using 3D-printed device and UHPLC-DAD/FLD analysis

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely employed in medicine for their anti-inflammatory and antipyretic properties. Their occurrence has been documented in effluents from wastewater treatment plants (WWTPs), as well as in aquatic ecosystems. NSAIDs are classified as emerging contaminants, thereby underscoring the importance of their environmental monitoring. This study presents a novel approach for the simultaneous on-site extraction of six NSAIDs –acetylsalicylic acid (ASP), celecoxib (CEL), diclofenac (DIC), ibuprofen (IBU), ketoprofen (KET), and naproxen (NAP)– from wastewater, followed by ultra-high performance liquid chromatography coupled with photodiode array and fluorescence detection (UHPLC-DAD/FLD). A 3D-printed device, coated with a highly selective solid-phase extraction (SPE) resin (Oasis HLB®), enabled on-site extraction and preconcentration of the analytes, avoiding to handle large sample volumes. A peristaltic pump helps both retention and elution steps. Method detection limits were 0.12 µg L^-1 for ASP, 0.16 µg L^-1 for CEL and IBU, 1.5 µg L^-1 for DIC, 0.09 µg L^-1 for KET and 0.19 µg L^-1 for NAP. The analytical performance of the 3D-printed device was demonstrated by precision below 5 % and the possibility of reusing up to 24 times without significant loss of extraction efficiency. An AGREEprep score of 0.53 classifies this methodology as moderately green. On-site analysis was conducted at the Calvià WWTP (Mallorca, Spain), where five NSAIDs were detected at various stages, demonstrating the feasibility of the on-site extraction across a broad concentration range. Except for ASP, which exhibited a recovery rate below 47 %, the remaining analytes showed satisfactory recoveries, ranging from 90 to 98 %.