Determination of Trace Heavy Metals Tl(I) in Water by Energy Dispersive X-Ray Fluorescence Spectrometry Using Prussian Blue Dispersed on Solid Sepiolite

Abstract

X-ray fluorescence (XRF) offers the advantage of performing measurements without damaging or consuming the sample, enabling rapid and simultaneous multi-element analysis. It has been widely applied in environmental monitoring, materials science, geology, and medicine, but not used in water. Here, a novel method is proposed that combines energy-dispersive X-ray fluorescence spectroscopy (EDXRF) with sepiolite-based Prussian blue nanomaterials (PB /SEP) and an integrated enrichment-separation device to detect trace heavy metal thallium (Tl(I)) in water environments. The water sample passes through the detachable enrichment component, and subsequently, PB/SEP is used as a solid adsorbent for the pre-enrichment of Tl(I) in the water sample. This process eliminates the cumbersome separation steps and saves analysis time. The research demonstrates the effects of sample pH, sample flow rate, sample volume and interfering ions on the elemental recoveries also are elucidated. The results demonstrate that the proposed method exhibited a low detection limit (0.057 μg/L) and good precision (RSD < 4.39%). Furthermore, the PB/SEP magnetic nanocomposite was successfully applied to tap water sample and river water sample with recoveries ranging from 93.5% to 128.3%, confirming the accuracy and practicality of the analytical method.

Keywords: Energy dispersive X-ray fluorescence spectrometry, Tl(I), PB/SEP, Water analysis, Pre-enrichment