Study of application of BCR sequential extraction procedure for fractionation of heavy metal content of soils, sediments, and gravitation dusts

This article deals with the application of original and modified Community Bureau of Reference (BCR) sequential extraction scheme for fractionation of contaminant metallic elements (Zn, Cd, Pb, Ni, Cr, and Cu) in sediments, soils, and aerial gravitation dusts. Contamination level and extractability of contaminant element in our internal laboratory soil, sediment, and gravitation dust reference samples was studied by original BCR procedure proposed to certified reference material (CRM) 601 sediment reference material. A preliminary comparative study was performed to control the extraction ability of original and modified BCR procedure using CRM 601 and 701, respectively. It was established that original BCR scheme can be applied for different kinds of samples (sediment, soil, dust) when necessary sample amount is available; however, one has to calculate with analyte losses due to pH instability during the second and third leaching steps and readsorption may occur after third leaching step during the phase separation. This latter observation was verified by direct solid sample analysis of original samples and third-step solid residue.