One-minute highly selective Cr(VI) determination at ultra-trace levels: An ICP-MS method based on the on-line trapping of Cr(III)

Davide Spanu; Damiano Monticelli; Gilberto Binda; Carlo Dossi; Laura Rampazzi; Sandro Recchia

doi:10.1016/j.jhazmat.2021.125280

One-minute highly selective Cr(VI) determination at ultra-trace levels: An ICP-MS method based on the on-line trapping of Cr(III)

J Hazard Mater. 2021 Jun 15:412:125280. doi: 10.1016/j.jhazmat.2021.125280. Epub 2021 Jan 30.

Authors

Davide Spanu¹, Damiano Monticelli¹, Gilberto Binda¹, Carlo Dossi², Laura Rampazzi³, Sandro Recchia⁴

Affiliations

¹ Department of Science and High Technology, University of Insubria, via Valleggio 11, Como 22100, Italy.
² Department of Theoretical and Applied Science, University of Insubria, via Dunant 3, Varese 21100, Italy.
³ Department of Human sciences and Innovation for the Territory, University of Insubria, via Sant'Abbondio 12, Como 22100, Italy.
⁴ Department of Science and High Technology, University of Insubria, via Valleggio 11, Como 22100, Italy. Electronic address: sandro.recchia@uninsubria.it.

PMID: 33550126
DOI: 10.1016/j.jhazmat.2021.125280

Abstract

An analytical method derived from the coupling of frontal chromatography (FC) with Inductively Coupled Plasma - Mass Spectrometry (ICP-MS) is proposed for the fast determination of Cr(VI) ultra-traces. The insertion of a short, homemade column filled with a strong cationic exchange resin in the flow-path of a commercial ICP-MS allows on-line trapping of cationic Cr(III) and elution of anionic Cr(VI). As a result, only the Cr(VI) front reaches the detector. This separation mechanism enables the highly selective quantification of Cr(VI) ultra-traces (LOD = 0.026 µg/kg - defined as 3 s of 10 replicated measurements of a 0.050 µg/kg solution) over a wide linearity range (tested up to 1024 µg/kg), even in the presence of Cr(III) concentration as high as 50 mg/kg. Key advantages of the proposed method are the extremely short analysis time (one minute), together with the simplicity and cost-effectiveness of the modifications applied over a commercial ICP-MS instrumental configuration. No time- or chemical-consuming pretreatments are needed: it is only necessary to acidify the sample prior Cr(VI) determination, as normally performed for common ICP-MS analysis. The applicability of the method was demonstrated over mineral water samples and toy migration solutions.

Keywords: Chromium speciation; Hexavalent chromium; ICP-MS; Mineral water; Trace determination.

Publication types

Research Support, Non-U.S. Gov't