Application of Rotating Coiled Columns to the Fractionation of Soil Particles and to the Sequential Extraction of Heavy-Metal Species from Silty, Dusty, and Sandy Fractions

Abstract

A complex procedure has been developed for evaluating the degree of soil contamination. Rotating coiled columns (RCCs) were used for both the fractionation of soil samples by their grain-size composition and the sequential extraction of heavy-metal species from silty, dusty, and sandy fractions. During the extraction of heavy-metal species, the soil fraction to be analyzed was retained in the column as a stationary phase, while aqueous solutions of extracting agents (mineral salts, acids, and complexing compounds) were sequentially pumped through the heterogeneous sample. The sequential extraction of element species from various soil fractions was carried out in the dynamic mode favorable to more complete extraction of metals. The use of RCCs allows the extraction of various heavy-metal species from soils to be performed in accordance with their grainsize composition. The process of the extraction of metal species can be automated, and in this case the losses of sample components are reduced to a minimum.

Dynamic leaching and fractionation of trace elements from environmental solids exploiting a novel circulating-flow platform

“…The average of RSDs of the acid bioaccessible metal concentrations in CRM sediment as obtained in five consecutive measurements by the AI method were in all instances better than those of the batch method (AI method: 3.9% for Cu; 6.3% for Zn; 5.4% for Cd; 8.0% for Pb vs batch method: 8.4% for Cu; 17.3% for Zn; 13.6% for Cd; 13.0% for Pb). The RSD values by the AI method were even far below than those reported in previous continuous-flow leaching methods for trace elements using acid extractants [34,37,38].…”

Is there a future for sequential chemical extraction?

“…An alternative means to achieve rapid results is to load the soil or sediment sample into a suitable container and perform the sequential extraction in continuous flow mode. Fritted centrifuge tubes, 345,[376][377][378] microcolumns [379][380][381][382] and rotating coiled columns [383][384][385][386][387] have been used for this purpose. Dedicated extraction cells 388 have been developed including one combining continuous-flow operation and microwave irradiation.…”

A Review of the Different Methods Applied in Environmental Geochemistry For Single and Sequential Extraction of Trace Elements in Soils and Related Materials

“…Some of the useful references in this area are Buanuam et al 2006;Nakazato et al 2006;Tongtavee et al 2005;Sun et al 2004Sun et al , 2005Vaeisaenen and Kiljunen 2005;Chomchoei et al 2004Chomchoei et al , 2005Jimoh et al 2005;Katasonova et al 2005;KrasnodebskaOstrega et al 2003;Davidson and Delevoye 2001.…”