Determination of 17 per- and Polyfluoroalkyl substances in Environmental water using magnetic nanoscale covalent organic framework-based LC-MS/MS

NH₂-MCOF enables ultra-sensitive detection of 17 PFASs down to 0.0346 ng/L. • Fast MSPE within 40 min and reusable for ≥6 cycles with stable performance. • Successfully detected PFASs in real urban waters, including 3.346 μg/L PFDS. Per - and polyfluoroalkyl substances (PFAS), as a class of persistent organic pollutants, are characterized by strong environmental persistence and high bioaccumulation potential, making them a major concern in global environmental and health fields. Currently, the trace detection of PFASs in urban environmental water samples, including surface water, source water, and domestic wastewater faces challenges such as insufficient adsorption selectivity of traditional materials and cumbersome pretreatment steps, highlighting the urgent need to develop efficient enrichment and highly sensitive analytical methods. To improve the enrichment efficiency of PFAS, this study designed and synthesized an amino-functionalized magnetic covalent organic framework material (NH₂-MCOF) as an adsorbent. Combined with magnetic solid-phase extraction (MSPE) and liquid chromatography-tandem mass spectrometry, a synchronous analytical method was established for the determination of 17 PFASs in real urban environmental water matrices. Through systematic optimization, the optimal pretreatment conditions were determined as follows: adsorbent dosage of 20 mg, solution pH of 3.0, ultrasonic-assisted adsorption time of 40 min, and a stepwise elution strategy using methanol, ammoniated methanol, and formic acid-modified methanol. Under the optimized conditions, the method demonstrated good linearity within the range of 0.5–200 μg/L, with detection limits of 0.0346–1.30 ng/L. The spiked recoveries ranged from 50% to 138%, and the intra -day and inter -day precision, expressed as relative standard deviations (RSD), were below 13.5% and 14.9%, respectively. Application to real water samples confirmed the method's effectiveness in detecting multiple PFASs, demonstrating its practicality and reliability. The analytical method established in this study integrates functionalized material design, efficient pretreatment, and sensitive detection, providing a reliable approach for the synchronous monitoring of multiple trace PFAS in real urban environmental water matrices and highlighting the potential application of functionalized magnetic covalent organic framework materials in environmental analysis. Download: Download high-res image (103KB) Download: Download full-size image