Agrawal O, Sunita G, Gupta V K
School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur, M.P., India.
Talanta. 1999 Jul 12;49(4):923-8. doi: 10.1016/s0039-9140(99)00091-0.
More than 70% of the earth surface is covered by water bodies. Marine pollution is associated with the discharge of oils, petroleum products, sewage agricultural wastes, pesticides, heavy metals, waste substances and dumping of radioactive waters in sea. This in turn results in hazards to human health, hindrance to aquatic organisms and impairment of quality for use of sea water. Sea water is reported to contain iodine but the concentration varies according to the location and depth. Here a simple and sensitive method is described for the determination of iodine using leucocrystal violet as a reagent in different samples of sea water. The method is based on the oxidation of iodine to iodate with bromine water and the liberation of free iodine from the iodate by addition of potassium iodide in acedic medium. This iodine selectively oxidises leucocrystal violet to form the crystal violet dye. Beer's law is obeyed over the concentration range of 0.04-0.36 ppm of iodine at lambda(max) 592 nm. The dye was further extracted in chloroform. The extracting system obeys Beer's law in the range of 0.008-0.08 ppm at lambda(max) 588 nm.
地球表面70%以上被水体覆盖。海洋污染与石油、石油产品、污水、农业废弃物、农药、重金属、废物的排放以及放射性废水倾倒入海有关。这进而对人类健康造成危害，阻碍水生生物生存，并损害海水的使用质量。据报道，海水中含有碘，但其浓度随位置和深度而变化。本文描述了一种简单灵敏的方法，使用无色结晶紫作为试剂测定不同海水样品中的碘。该方法基于用溴水将碘氧化为碘酸盐，并在酸性介质中加入碘化钾使碘酸盐释放出游离碘。这种碘选择性地将无色结晶紫氧化形成结晶紫染料。在592nm波长下，碘浓度在0.04 - 0.36ppm范围内符合比尔定律。染料进一步用氯仿萃取。萃取体系在588nm波长下，碘浓度在0.008 - 0.08ppm范围内符合比尔定律。
