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

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 miniaturised 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 (steps 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.

Atomic spectrometry update – a review of advances in environmental analysis

“…The total mass recovery was 72% of that obtained by conventional offline extraction because lower extractant concentrations and shorter extraction times were used. To determine the physico-chemical partitioning of PTEs in airborne PM, Sagagi et al 124 developed two non-specific flow-through sequential extraction procedures with chemometric identification of substrates and element distribution (CISED) methodology. One method was based on reduction of sample requirement (2 g of sample and 10 mL of extractant) for a standard CISED extraction to 0.1 g of sample and 3 mL extractant.…”