Comparison of two sequential extraction procedures for the fractionation of zinc in agricultural calcareous soils

Abstract

Twenty soil samples with a wide range of chemical and physical properties were collected from typical uncontaminated soils of south-west Iran, characterised by their high calcium carbonate contents (mean value of 321 g kg À 1 ) and zinc deficiency (mean value of 0.2 mg kg À 1 for DTPA-extractable Zn). The extractability and solid-phase fractionation of Zn in the soils was determined by the single extraction procedure (DTPA extractability) and two different sequential extraction procedures: a seven-step Singh method (procedure A) and the modification of three-step BCR (Community Bureau of Reference) method (procedure B). The DTPA extractable zinc levels were low (on average 3.34%). Zinc was mainly contained in the residual fraction (91.43% for procedure A and 75.25% for procedure B). In comparison with procedure B, few relationships were established between the zinc fractions isolated by procedure A and the soil properties. The Singh scheme provided better information than the BCR scheme about Zn distribution in the soils studied.

Application of flexible multi-elemental ICP-OES detection in fractionation of potentially toxic element content of solid environmental samples by a sequential extraction procedure

“…When for determination the PTE-contents of these solutions the multi-elemental capacity of spectrochemical analytical techniques like inductively coupled plasma optical emission spectrometry (ICP-OES) or inductively coupled plasma mass spectrometry (ICP-MS) should be utilized, we have to calculate with significant solvent-matrix interferences, which may strongly influence the reliability of analytical results. Up to now methodological developments to improve the BCR system have been mainly focused on extraction procedures: continuous flow systems were developed [ 12,13,14,15,16,17], alternative reagents were applied [18,19,20,21,22] and acceleration of batch leaching by sonication [23] or microwave treatment [24] was applied. A review of the methodological development of the BCR sequential extraction procedure was given in our previous papers [25a,b].…”

Longterm study of transformation of potentially toxic element pollution in soil/water/sediment system by means of fractionation with sequential extraction procedures

“…These changes should be considered in long term studies of PTE-contamination when consistency with former data is required [17]. The original and the modified BCR-procedures were successfully applied for risk assessment of PTE contaminations in aquatic sediments and soils, however, CRM sample for fractionation of PTE-content of soils was not issued up to now [17][18][19][20][21][22][23][24][25][26][27]. Application in environmental risk assessment of PTE-fractionation based on the classification of Tessier [5] should require more and more the standardization of the sequential extraction procedures but the methodological problems hindered this up to now.…”