RT Journal Article T1 Optimization, validation and application of a novel multiresidue method for prioritization of contaminants of emerging concern in biosolids A1 Barros Soto-Quiroga, Andrés A1 Castro Varela, Gabriela A1 Ramil Criado, María A1 Rodríguez Pereiro, Isaac K1 Pharmaceuticals K1 Biosolids K1 Occurrence K1 Liquid chromatography mass spectrometry K1 Environmental risk assessment AB Biosolids generated during municipal wastewater treatment are a source of organic matter and essential macronutrients, making them valuable to increase the fertility of soils. However, they also contain variable concentrations of micropollutants, particularly pharmaceuticals, which can pose environmental risks. An analytical methodology based on QuEChERS extraction and LC-MS/MS analysis was optimized and applied to the determination of 59 micropollutants, with large variations in their polarities and different uses, in biosolids from sewage treatment plants (STPs). Extraction efficiencies above 80%, and moderate variations in the efficiency of electrospray ionization were achieved for most of the target analytes in biosolids from different STPs. The accuracy of the final method ranged from 80% to 120% for 57 out of 59 micropollutants, with limits of quantification between 1 and 5 ng g−1, except for chlorhexidine (50 ng g−1). Forty-nine pollutants showed detection frequencies above 70%, with thirty-six compounds quantified in 100% of biosolids from 27 STPs. Biocides and psychiatric drugs represented more than 75% of residues in biosolids, with average accumulated concentrations of 5149 and 2425 ng g−1 (dry weight, d.w.), respectively. Within the first group, the maximum concentrations of azithromycin and chlorhexidine stayed above 2300 ng g−1 and 11,000 ng g−1 d.w., respectively. Ecological risk assessment of biosolids-amended soils identified fifteen compounds whose potential leaching into aquatic environments warrants further investigation. Significative accumulation in biosolids of several pharmaceuticals listed in the Wastewater Directive must be considered together, with their residues in raw and treated wastewaters, to estimate their real removal at STPs. PB Elsevier SN 0026-265X YR 2026 FD 2026-04-30 LK https://hdl.handle.net/10347/47198 UL https://hdl.handle.net/10347/47198 LA eng NO Barros, A., Castro, G., Ramil, M., & Rodríguez, I. (2026). Optimization, validation and application of a novel multiresidue method for prioritization of contaminants of emerging concern in biosolids. Microchemical Journal, 225, 118188. 10.1016/j.microc.2026.118188 NO We acknowledge the financial support received through SAFESLUDGE project, ref. PID2023-147051OB-I00, funded by Ministry of Science, Innovation and Universities & Estatal Agency of Research (MICIU/AEI/10.13039/501100011033), and the regional administration (Xunta de Galicia, project ED431C 2025/21). We also thank Agilent for providing free access to the LC-MS/MS QqQ equipment employed in this research. DS Minerva RD 22 may 2026