Optimalization and application of iodine spectrophotometric determination in soils.

This work deals with the content of iodine in soils, furthermore with obtaining and processing samples from four selected sampling areas, all of which are in the proximity of the Arnoštov settlement in district Prachatice in the foothills of Šumava. The soil samples were obtained from forest, meadow, pasture and fallow soil in 2009 to 2011. The iodine content in the soils was determined by using the spectrophotometric method, which had been optimized for the soil samples. Iodine concentration in lysimeter water was determined by using method inductively coupled plasma - mass spectrometry. The results obtained from each sampling areas were compared with each other and with the results from other areas. Consequently, the iodine concentration results in the soils were compared with the iodine concentration in lysimeter waters. It was found, that the highest iodine content in soils was measured in a sample obtained from Area 1 (meadow), part B in a depth of 16 - 30 cm in June of 2009, namely a content of 8,67 mg of I per kg of dry soil. The lowest content of 1,42 mg of I per kg of soil was found in the area 4 (forest), sample obtained in June of 2010, in the L horizon. By comparing iodine content with iodine concentrations in lysimeter waters, it was concluded that the concentration of iodine in lysimeter waters does not depend on iodine concentrations in soils and that it does not even represent the absolute iodine content in soil, as was determined by comparing the results from Arnoštov with data acquired from Agrovýzkum Rapotín in Jeseníky