A critical study of the use of hydrogen peroxide to determine trace metalsbound to soil organic matter

The risk due to the presence of large amounts of trace metals in soils is r elated strongly to their speciation, which is usually estimated by sequenti al extraction procedures. However, this approach is now very controversial. As one of the soil compartments responsible for the trace metal fixation i s the organic matter, the aim of this work was to study the reliability of the use of a chemical reagents such as hydrogen peroxide in determining the trace metal quantities bound to the soil organic matter. A comparison of t he quantities of trace metals extracted by H+ or H+ + H2O2 for different va lues of the final pH, has shown that an optimal pH is required in order to provide the best estimate of trace metals bound to soil organic matter, whe n using for this goal the hydrogen peroxide, Using this approach, we found for example that more than 60% of copper is truly bound to organic matter.