Development and validation of an efficient analytical method for the simultaneous detection of 46 antibiotics in freshwater and sediments

An approach was established for the identification and quantification of 46 antibiotic residues in water and sediment, employing ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Solid-phase extraction (SPE) was used to enrich the antibiotics from water-phase samples, utilising an Acquity BEH C18 column for separation and tandem mass spectrometry for detection. The extraction process involved the addition of magnesium nitrate, acetonitrile, and aqueous ammonia to sediment samples. Additionally, testing conditions were optimised to determine trace concentrations (ng/L), which included adjustments to the extractant, eluent, elution volume, and other relevant parameters. Method validation was performed, encompassing assessments of linearity, accuracy, method detection limits (MDLs), and method quantification limits (MQLs). The results demonstrate that the method exhibits high accuracy and precision. The average recoveries of samples from water and sediment ranged from 51.45% to 128.25%. The MDLs for the targeted antibiotics ranged from 0.01 to 0.20 ng/L in water and from 0.003 to 0.05 ng/g in sediments, with corresponding MQLs of 0.04 to 0.68 ng/L and 0.01 to 0.17 ng/g, respectively. Water and sediment samples collected from rivers surrounding Chaohu Lake were analysed for antibiotic residues to demonstrate the method’s applicability to real-world samples. The results confirmed the method’s capability to effectively analyse antibiotics at ultra-trace levels in environmental water and sediment samples.