Fractionation of various elements in CRMs and in polluted soils

Abstract

An optimised BCR three steps sequential extraction procedure (BCR SEP) and several single extractions with KCl, NH(4)Cl, Na(4)P(2)O(7) and 0.5 mol L(-1) HCl were used for the fractionation of Al, Cu, Fe, Mn, Pb and Zn in CRMs and in samples from a mining area with sulphidic deposits. A good interlaboratory comparability was obtained for Cu, Pb and Zn in CRM 483, CRM 701, SRM 2710 and SRM 2711 by BCR SEP. The reliability of the results obtained is also very satisfactory. Some differences were found between our results and the indicative data for Al and Fe fractionation. However, serious discrepancies were found for Mn, not only for individual steps of the fractionation, but for the data obtained overall (sum of 1-3 steps), and for the total concentration as well. Our results could be utilized as a contribution to the existing indicative values for CRM 483, SRM 2710 and SRM 2711 for interlaboratory study. Moreover, data for the fractionation of elements mentioned above for CRM 701 are first presented here.A high correlation between 0.5 mol L(-1) of HCl-extractable amounts of the elements studied, and the sum of the three steps of BCR SEP in acid sulphatic weathering products and naturally acidified soils was established, which allows us to suggest this rapid and cost-effective single extraction procedure as a valuable tool in contamination assessment.

Comparative study of optimised BCR sequential extraction scheme and acid leaching of elements in the certified reference material NIST 2711

“…Whilst results have previously been reported for Pb, Al, Mn, Fe, Cu and Zn using the optimised BCR procedure [24,25], discrepancies existed between those studies for Pb, Al and Mn. This work clarifies those discrepancies, and provides partitioning results for Cd, Sb, Cr, Co, Ni and As under the optimised BCR procedure.…”

“…Original results for Mn were incorrectly published and revised results are shown [29]. d Optimised BCR procedure [25].…”

“…The partitioning between phases of Pb, Al, Mn, Fe, Cu and Zn in NIST 2711 has previously been investigated using the optimised BCR procedure by Sutherland et al and also by Kubová et al [24,25], and prior to this Ho and Evans [23] have reported the fractionation of Cd, Cu, Pb and Zn using the original BCR procedure. As mentioned previously, the original BCR procedure was modified with the main difference being an increase in the concentration of the reducing agent used in Previous results for Cd, Cu, Pb and Zn partitioning in NIST 2711 by Ho and Evans [23] using the original BCR procedure have also been included in Table 3.…”

“…A number of other reference materials, including NIST 2711 (soil certified for total metals and non-certified EPA Method 3050 leachable concentrations), have been used for assessing sequential extraction procedures. NIST 2711 is a moderately contaminated soil intended for quality assurance of analysis of soils and sediments, and although no certified values exist for sequential extractions performed upon NIST 2711, a variety of sequential extraction procedures have been applied to this reference material [21][22][23][24][25].…”

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

“…Several studies of application of sequential extraction methods to different reference materials had been carried out by various workers and few selected examples are Zemberyova et al 2006Zemberyova et al , 2007Vasile et al 2006;Larner et al 2006;Matus et al 2006;Kubova et al 2004Kubova et al , 2005Pueyo et al 2005;Tack 2002, 2003;Rauret and LopezSanchez 2001;Rauret et al 1999;Ho and Evans 1997;Hall et al 1996a, b;Li et al 1995a, b etc.…”