Volume 28, Number 9, November 2000Endocrine disruptors
|Page(s)||808 - 812|
Efficiency of extractants to release As, Cd and Zn from main soil compartmentsJ. Száková, P. Tlustos, J. Balík, D. Pavlíková and M. Balíková
Department of Agrochemistry and Plant Nutrition, Czech University of Agriculture, 165 21 Prague 6, Suchdol, Czech Republic
(Received June 29, 2000; revised September 28, 2000; accepted October 10, 2000.)
Various soil extraction methods were developed for the determination of total and/or plant-available concentrations of potentially toxic elements. In this experiment, four single extraction procedures (aqua regia, HNO3, acetic acid, DTPA) were tested for the determination of extractable contents of As, Cd and Zn. 35 soils differing in their physicochemical properties and in total element contents were used in this experiment. Extractability of elements from soil samples varied following the individual elements and/or extraction agents used. The strong acids were not able to release the elements tightly bound into the silicate sample matrix. However, such techniques remain utilizable for the approximate determination of "pseudototal" element contents in soil, especially if soil samples are affected by anthropogenic contamination. The concentrations of As, Cd, and Zn determined in soil extracts by both mineral and organic acids covered in most cases the element portion representing more than one soil element fraction determined using SM&T sequential extraction procedure. Solutions of acetic acid and DTPA were able to release a part of the element fraction bound in Fe/Mn oxides and organic matter of soil sample. Arsenic represents an exception because it is not released by DTPA.
Key words: As -- Cd -- Zn -- soil -- extractionaqua regia -- nitric acid -- acetic acid -- DTPA.
© EDP Sciences, Wiley-VCH 2000