On-site Determination of Arsenic, Selenium, and Chromium(VI) in Drinking Water Using a Solid-phase Extraction Disk/Handheld X-ray Fluorescence Spectrometer

Abstract

A rapid, simple technique combining disk solid-phase extraction and handheld X-ray fluorescence (XRF) spectrometry was developed for the on-site determination of As, Se, and Cr(VI) in drinking water. For the pre-concentration of As, Se, and Cr(VI), a 50 mL aqueous sample was adjusted to pH 4, followed by passage through a Ti-loaded anion-exchange disk (Ti-AED). Both sides of the Ti-AED were coated with an adhesive cellophane tape prior to drying using a cordless hair iron, followed by handheld XRF measurement. The Ti-AED adsorbed As(III), As(V), Se(IV), Se(VI), and Cr(VI) in water without requiring oxidation and reduction. The detection limits of As, Se, and Cr(VI) were all 1.0 g L 1 . Good recoveries were obtained by measuring certified reference materials, and spiking natural mineral water with As, Se, and Cr(VI). As the proposed method does not require power supply or toxic reagents in any analytical step, it is suitable for the on-site determination of toxic elements in drinking water.

Solid-Phase Extraction for Environmental Analysis

“…Hagiwara et al reported the on-site determination of As, Se, and Cr(VI) in drinking-water samples using handheld XRF spectrometry with a Ti-loaded anion-exchange disk SPE. 10 The detection limits of the metal ions were all 1.0 μg L -1 . He et al reported the use of universal polymeric reversed-phase and polymeric strong cation exchange cartridges combined with LC-MS/MS analysis for the determination of caffeine and its seven metabolites in wastewater samples.…”

Real-Time On-Site Multielement Analysis of Environmental Waters with a Portable X-ray Fluorescence (pXRF) System

“…Hagiwara et al reported a method utilizing an anion-exchange disk to preconcentrate metals. 11 The disks were analyzed with a pXRF, and the metal concentration of the initial water sample was calculated using empirical calibration. Although the system does not require an electrical outlet or use of toxic chemicals, it still requires the operator to prepare the sample disks for the XRF measurement by taping them on both sides with cellophane tape and drying the disks with a cordless hair iron.…”

“…In recent years, different preconcentration procedures combined with portable X-ray fluorescence (pXRF) spectrometry to analyze metal concentrations in aqueous samples have been reported. − Preconcentration improves the analytical detection limits of the XRF technology from a milligrams per liter (mg/L) to a micrograms per liter (μg/L) level to meet the environmental guidelines for dissolved metals. The analytical method to be utilized in field conditions needs to be simple with minimal sample preparation.…”

X-ray Fluorescence Spectrometry

“…Hagiwara et al proposed a rapid, simple technique that combines disk solid-phase extraction and handheld XRF spectrometry for the on-site determination of As, Se and Cr(VI) in drinking water. 5 A Ti-loaded anion-exchange disk was used to collect As(III), As(V), Se(IV), Se(VI), and Cr(VI) in water without requiring oxidation and reduction. The detection limits of As, Se, and Cr(VI) were all 1.0 μg L -1 .…”