Li Na, Shi Laishun, Wang Xiaomei, Guo Fang, Yan Chunying
School of Chemistry and Chemical Engineering, South Campus, Shandong University, Jinan 250061, China.
Int J Anal Chem. 2011;2011:130102. doi: 10.1155/2011/130102. Epub 2011 Jul 26.
The mole ratio r(r = I(-)/ClO(2)) has great influence on ClO(2)-I(-)-H(2)SO(4) closed reaction system. By changing the initiate concentration of potassium iodide, the curve of absorbance along with the reaction time was obtained at 350 nm and 297 nm for triiodide ion, and 460 nm for iodine. The changing point of the absorbance curve's shape locates at r = 6.00. For the reaction of ClO(2)-I(-) in the absence of H(2)SO(4), the curve of absorbance along with the reaction time can be obtained at 350 nm for triiodide ion, 460 nm for iodine. The mole ratio r is equal to 1.00 is the changing point of the curve's shape no matter at which wavelength to determine the reaction. For the reaction of ClO(2)-I(-)-H(+) in different pH buffer solution, the curve of absorbance along with the reaction time was recorded at 460 nm for iodine. When r is greater than 1.00, the transition point of the curve's shape locates at pH 2.0, which is also the point of producing chlorite or chloride for chlorine dioxide at different pH. When r is less than 1.00, the transition point locates at pH 7.0.
摩尔比r（r = I⁻/ClO₂）对ClO₂ - I⁻ - H₂SO₄封闭反应体系有很大影响。通过改变碘化钾的初始浓度，在350 nm和297 nm处获得了三碘离子吸光度随反应时间的曲线，在460 nm处获得了碘的吸光度随反应时间的曲线。吸光度曲线形状的变化点位于r = 6.00处。对于在无H₂SO₄情况下的ClO₂ - I⁻反应，在350 nm处可获得三碘离子吸光度随反应时间的曲线，在460 nm处可获得碘的吸光度随反应时间的曲线。无论在哪个波长测定反应，摩尔比r等于1.00都是曲线形状的变化点。对于在不同pH缓冲溶液中的ClO₂ - I⁻ - H⁺反应，在460 nm处记录了碘吸光度随反应时间的曲线。当r大于1.00时，曲线形状的转变点位于pH 2.0处，这也是二氧化氯在不同pH下生成亚氯酸盐或氯化物的点。当r小于1.00时，转变点位于pH 7.0处。
