Single-Step Extraction to Determine Soluble Lead Levels in Soil

Abstract

This study investigated single-step extraction using EDTA to extract the amount of potentially soluble Pb in soil, which would be almost as much as that in the first four Pb fractions of Tessier’s sequential extraction procedure (SEP), with or without the immobilization amendment hydroxyapatite under different extraction conditions such as concentration and extractant pH. The results clearly showed that 0.1M EDTA (pH 7.5) with a soil/extractant ratio of 1:100 can extract almost 90% of the first four Pb fractions of SEP, and EDTA-extracted Pb was positively correlated with the first four Pb fractions even in Pb-immobilized soil. In conclusion, single-step extraction using EDTA was found to be a useful method to evaluate potentially soluble Pb even in Pb-immobilized soils.