Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025010402
Vegetable consumption is a well-established pathway for human exposure to per- and polyfluoroalkyl substances (PFAS). These contaminants are absorbed by vegetables through uptake from soil and irrigation water, leading to bioaccumulation within plant tissues and posing potential risks to human health. Therefore, monitoring PFAS concentrations in vegetables is critical for assessing dietary exposure and associated health risks. In this study, a solid-phase extraction (SPE) followed by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the determination of 24 PFAS compounds in leafy vegetables, including Shanghai Bok Choy, Cabbage, and Water Spinach. The analytical method, incorporating organic solvent extraction followed by SPE cleanup, was optimized with respect to both extraction solvent and SPE sorbent. Alkaline methanol was used as the extraction solvent, and PFAS in vegetables were extracted via vortex-assisted extraction. Tandem mass spectrometry was used for detection in multiple reaction monitoring mode, and quantification was performed by internal standard method. Under optimized conditions, at a spiking level of 2 ng, recoveries ranged from 50.0% to 120.8% with relative standard deviations (RSD) between 1.0% and 26%. Calibration curves showed good linearity with correlation coefficients (r) greater than 0.99. Limits of detection (LOD, S/N=3) were between 0.002 and 0.103 ng·g−1, and limits of quantification (LOQ, S/N=10) were between 0.007 and 0.343 ng·g−1. The method was applied to real samples, detecting 20 PFAS, with 10 compounds showing 100% detection frequency. Total PFAS concentrations ranged from 2.92 to 6.83 ng·g−1 dry weight (dw). Perfluorobutanoic acid (PFBA) was the dominant contaminant, with concentrations from 1.18 to 3.74 ng·g−1 dw. The method demonstrates good sensitivity and accuracy, effectively identifying and quantifying multiple PFAS, thus providing reliable technical support for monitoring PFAS in vegetables.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025010608
This study investigated the occurrence and distribution of 27 per- and polyfluoroalkyl substances (PFAS) in surface water and sediment of the Fuchun River, a tributary of the Qiantang River Basin. Surface water samples were analyzed using ultra-performance liquid chromatography coupled with high-resolution mass spectrometry. Total PFAS concentrations (∑PFAS) in surface water ranged from 30.04 to 105.26 ng/L, with mean and median values of 59.64 ng/L and 51.43 ng/L, respectively. The dominant compounds were perfluorooctanoic acid (PFOA), hexafluoropropylene oxide dimer acid (GenX), and perfluorobutanoic acid (PFBA). Concentrations generally decreased from upstream to downstream, consistent with previous studies. Notably, GenX levels were significantly elevated compared to earlier reports. In sediment, ∑PFAS concentrations ranged from not detected (ND) to 0.59 ng/g dry weight, with mean and median values of 0.14 ng/g and 0.11 ng/g, respectively. PFOA and perfluorooctanesulfonic acid (PFOS) were the primary sediment contaminants. Source apportionment indicated that industrial wastewater discharge and sewage treatment plant effluents were the main sources of PFAS in the river. Risk assessment using risk quotients suggested low ecological risks to aquatic organisms for most detected PFAS. However, the presence of short-chain and novel PFAS warrants further investigation due to potential unknown risks.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025112603
The cycloaddition of carbon dioxide (CO2) to epoxides (CCE) is a 100% atom-economical transformation yielding cyclic carbonates, which are valuable chemical products. This reaction valorizes CO2 as a carbon feedstock, mitigating the greenhouse effect and aligning with carbon neutrality goals. Conventional covalent organic framework (COF) catalysts often require co-catalysts to achieve high efficiency. To address this, we designed and prepared a series of ionic COFs, denoted EB-BT(nOH), that simultaneously incorporate acid (hydroxyl), base (nitrogen), and nucleophilic bromide (Br−) functionalities. These materials efficiently catalyze the CCE reaction without any co-catalyst. Among them, EB-BT(OH) exhibited the highest catalytic activity, achieving a 99% yield of the target product at 120 °C and 2.0 MPa CO2 pressure. By systematically varying the hydroxyl content in the COF backbone, we investigated the critical role of hydrogen bond donors (HBDs) in the CCE reaction. This work provides new design principles for COF-based catalysts for CCE, eliminating the need for co-catalysts and enhancing process sustainability.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025021401
This study investigated the occurrence, distribution, sources, and ecological risks of 19 organophosphate triesters (OPEs) and 8 diesters (di-OPEs) in surface water and sediments from the Hangzhou section of the Qiantang River. Samples were analyzed using liquid chromatography-high resolution mass spectrometry. Concentrations of ΣOPEs in water ranged from 31.5 to 98.9 ng/L, and in sediments from 10.8 to 341 ng/g dry weight (dw). Σdi-OPEs ranged from 2.19 to 104 ng/L in water and 0.437 to 106 ng/g dw in sediments, indicating moderate to low contamination. TCIPP and TCEP dominated OPEs in water, while TEHP was the predominant OPE in sediments. DBP was the major di-OPE in water, and DPHP in sediments. Source apportionment via correlation and principal component analysis identified industrial production and human activities, including household, tire, plastic manufacturing, and agricultural practices, as primary sources. Ecological risk assessment revealed negligible risks for most OPEs in water, but notable risks in sediments: TEHP and EHDPP posed risks to crustaceans, and TPHP to algae. Moreover, combined toxicity at multiple sediment sampling sites raised concern, warranting further attention.