Electrospun nanofibrous mercury filter: Efficient concentration and determination of trace mercury in water with high sensitivity and tunable dynamic range

•We reported a simple and highly sensitive method for the determination of trace mercury in water samples based on a novel thiol-containing electrospun nanofibrous mercury filter (ENMF) and the direct mercury analyzer (DMA).•A novel electrospun nanofibrous mercury filter (ENMF) was developed for concentration and determination of mercury in water.•This strategy provided a amplification-free approach to the highly sensitive mercury determination, and extended the application of electrospun nanofibrous membranes for environmental pollutants analysis.

Herein, we reported a simple and highly sensitive method for the concentration and determination of trace mercury in water samples based on a novel electropsun nanofibrous mercury filter (ENMF). The method consisted of two simple steps: first, the concentration of mercury on a piece of thiol-containing ENMF; and second, the determination of mercury captured on the ENMF using a direct mercury analyzer (DMA). By changing the volume of water sample, the dynamic range of the method could extend from 0.0025 to 6.0 ng/mL with the lowest limit of detection (LOD) of 2.5 pg/mL (2.5 ppt, 12.5 pM). The proposed method exhibited good precision with the relative standard deviations (RSDs, n = 11) of 9.4%, 5.5%, and 3.7% at the concentrations of 0.01, 0.1 and 1.0 ng/mL, respectively, as well as satisfying accuracy for the analysis of certified reference materials (GSB 07-3173-2014 202033 and GBW 08603). The proposed method showed good agreement with the Chinese AFS standard method (GB/T 5750.6) in the measurement of three different real water samples, with the relative errors of −6.2-2.6% and standard addition recoveries of 90.6-108.2%. This strategy provided a simple and efficient approach to the highly sensitive determination of trace mercury in water, and extended the application of electrospun nanofibrous membranes for environmental pollutant analysis.

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