Comparison of two non-specific flow-through sequential extraction approaches to identify the physico-chemical partitioning of potentially harmful elements in a certified reference material

Balarabe S Sagagi; Christine M Davidson; Mark R Cave; Joanna Wragg

doi:10.1016/j.talanta.2020.121685

Comparison of two non-specific flow-through sequential extraction approaches to identify the physico-chemical partitioning of potentially harmful elements in a certified reference material

Talanta. 2021 Feb 1;223(Pt 1):121685. doi: 10.1016/j.talanta.2020.121685. Epub 2020 Sep 24.

Authors

Balarabe S Sagagi¹, Christine M Davidson², Mark R Cave³, Joanna Wragg³

Affiliations

¹ WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK.
² WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK. Electronic address: c.m.davidson@strath.ac.uk.
³ British Geological Survey, Keyworth, NG12 5GG, UK.

PMID: 33303139
DOI: 10.1016/j.talanta.2020.121685

Abstract

Two non-specific sequential extraction methods utilising chemometric data processing (chemometric identification of substrates and element distribution, CISED) have been developed and used to determine the physico-chemical partitioning of potentially harmful elements (PHE) in certified reference material BCR CRM 701 (lake sediment). A miniaturized centrifugation method in which the sample was extracted on a filter insert in a polypropylene centrifuging tube, and a quasi-flow through method in which the sample was supported on a TX40 filter in a 47 mm in-line polycarbonate filter holder, gave similar results. The CISED data processing identified nine components. Seven of these were of geochemical origin - two carbonate components, an Al/Fe oxide/hydroxide component, three Fe-dominated components and one Si-dominated component - while the others represented the TX40 filter blank. The overall extraction capabilities of the methods were similar to that of the well-established BCR sequential extraction (Σsteps 1-3). However, whilst the BCR extraction is operationally defined, the CISED provides information on associations between PHE and the geochemical components identified. The flow through CISED procedure has potential applications in investigating the chemical speciation of PHE associated with urban airborne particular matter.

Keywords: Airborne particulate matter; BCR CRM 701; CISED; Chemometrics; Inductively coupled plasma mass spectrometry; Sequential extraction.