Development and validation of extraction methods for determination of zincand arsenic speciation in soils using focused ultrasound - Application to heavy metal study in mud and soils

To evaluate metal availability in soils many extraction procedures exist wh ich can be divided in two groups: sequential extraction and simple extracti on. Both extraction procedures are time consuming, because they need long m echanical shacking time. Nowadays, ultrasonic extraction is merging as an a lternative to develop more rapid methods. Methods have been optimised and validated for replacing extraction with mec hanical shaking by sonication in order to simplify analytical procedures, w hich is highly necessary when many samples have to be tested. Zinc and arse nic have been selected for developing total and sequential extraction proce dures. Chemical species of arsenic have been determined. These methods have been successfully applied to the determination of heavy metal content in f ractions and soluble metal in mud coming from Aznalcollar spill, soils cont aminated with them and control soils to evaluate the degree of contaminatio n and bio-availability of different metals. (C) 2001 Elsevier Science B.V. All rights reserved.