The determination of iodine in geochemical samples: The use of pyrohydrolytic decomposition

A relatively fast and efficient extraction method for iodine is essential as awareness of the importance of the element in biological and environmental systems grows. The pyrohydrolysis method described here has been tested and developed specifically for the release of iodine from geochemical samples. Vanadium pentoxide is used as a flux for pyrohydrolysis of the sample at 1060°C for fifteen minutes with absorption of the released iodine in 0.05M NaOH solution. Iodine is subsequently determined by automated colorimetry. A detection limit of 0.05 μgg−1 I in the solid phase is achieved.