Comparison of original and modified BCR sequential extraction procedures for the fractionation of copper, iron, lead, manganese and zinc in soils and sediments

• Published in: Analytica chimica acta Vol. 478; no. 1; pp. 111 - 118
• Main Authors: Mossop, Katherine F, Davidson, Christine M
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 12.02.2003; Elsevier
• Subjects: Analysis methods; Analytical chemistry; Applied sciences; BCR sequential extraction; Chemistry; Exact sciences and technology; Extractable trace metals; General, instrumentation; Operational; Pollution; Soil and sediments pollution; Extractable trace metals; Operational; BCR sequential extraction; Trace analysis; Fractionation; Chemical analysis; Sequential extraction; Iron; Hydroxylammonium compounds; Soil pollution; Sediments; Sewage sludge; Zinc; Chemical enrichment; Ammonium chloride; Soils; Lead; pH; Copper; Comparative study; Manganese
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/S0003-2670(02)01485-X

This article describes a detailed comparison between the original BCR sequential extraction procedure, step 2 of which involves treatment with 0.1 mol l −1 hydroxylammonium chloride at pH 2, and the revised BCR procedure (step 2: 0.5 mol l −1 hydroxylammonium chloride at pH 1.5). An intermediate protocol was also evaluated in which 0.5 mol l −1 hydroxylammonium chloride at pH 2 was used. The procedures were applied to five soil and sediment substrates: a sewage sludge-amended soil, two different industrially contaminated soils, a river sediment and an inter-tidal sediment. Extractable iron and manganese concentrations were measured to assess the effects of the procedural modifications on dissolution of the reducible matrix components. Trace elements copper, lead and zinc were also determined. Statistical analysis (two-tailed t-tests at 95% confidence interval) indicated that recovery of iron in step 2 was not markedly enhanced when the intermediate protocol was used. However, significantly greater amounts were isolated with the revised BCR scheme than with the original procedure. Copper behaved similarly to iron. Lead recoveries were increased by use of both modified protocols, with the greatest effect occurring for the revised BCR extraction. In contrast, manganese and zinc extraction did not vary markedly between procedures. The work indicates that the revised BCR sequential extraction provides better attack on the iron-based components of the reducible matrix for a wide range of soils and sediments.