Factors affecting 2,4-D extractability from high humic matter content soil samples.

MERINI, LJ; CUADRADO, V; GIULIETTI, AM

Neuquen

Congreso; XVI Congreso Argentino de Toxicología.; 2007

The 2,4-dichlorophenoxyacetic acid (2,4-D) is a hormone-like herbicide widely used in agriculture. Although its half life in soil is approximately 1 to 2 weeks, the thousand of tons introduced in the environment every year represent a risk for human health and the environment. Due to the toxic properties of this compound and some of its degradation products the assessment and monitoring of 2,4-D residues in agricultural soils is important. At the same time, several experiments of phyto/bioremediation are carried out to find an economic and environmental friendly tool to restore the polluted soils. In both cases, it is very important to accurately measure the amount of 2,4-D and its metabolites in soils. There is evidence that 2,4-D extraction from soil samples seriously depends on the physical and chemical properties of the soil, especially those soils with high content of humic acids. The issue of this work is to assess the multiple variables that influence the recovery and subsequent analysis of 2,4-D and the main metabolites from soil. The results obtained show that recovery efficiency is affected mainly by: the solvent and method used for the extraction, the amount and solvent used for dissolving the herbicide and the soil water content at the moment of spiking. An optimized protocol for the extraction and quantification of 2,4-D and its main metabolite from soil samples is presented.