DETERMINATION OF THE TOTAL AND LEACHABLE AMOUNTS OF ORGANOHALOGENS INSOIL

Different pretreatments of soil samples were combined with incineratio n in oxygen atmosphere and microcoulometric titration of formed hydrog en halides to determine the total and leachable amounts of organically bound halogens (TOX and LOX, respectively). The results showed that t he investigated procedures can be standardised to provide reproducible results. In general, inorganic chloride present in soil particles and microorganisms did not have any significant impact on measured LOX co ncentrations. The possible impact of chloride on the determination of TOX in soil is more uncertain. However, even though analytical artifac ts cannot be completely ruled out, there was strong evidence that the TOX measurements resulted in adequate estimates of the true organohalo gen content of the analysed soil samples. A substantial part of the TO X was recovered as LOX by leaching with NaOH, and there was a good agr eement between TOX-to-l.o.i. ratios of dried and ground soil samples a nd AOX-to-TOC ratios of leachates of the same samples.