β-环糊精增敏橙黄Ⅳ分光光度法测定亚硝酸根离子

Determination of Nitrite Ion by β-cyclodextrin Sensitizing Orange Ⅳ with UV-vis Spectroscopy

利用β-环糊精(β-CD)对橙黄Ⅳ的超分子包合作用,建立了β-CD增敏橙黄Ⅳ测定亚硝酸根离子的新方法。结果表明,β-CD与橙黄Ⅳ在不同的温度下均形成了1∶1的包合物,从包合常数K_a可知高温不利于包合反应的进行。由于β-CD对橙黄Ⅳ的亚硝化产物的包合作用,使吸光度增大,检测灵敏度提高。NO^-_2在0~0.82μg·m L^(-1)范围内符合朗伯-比尔定律。

A new method was developed for the determination of nitrite ion by β-cyclodextrin （β-CD） sensitizing orange IV being supramolecular inclusion of β-CD and orange IV. The result showed that 1 ： 1 （orange IV ： β-CD） inclusion complexes were formed, higher temperature did not favor the inclusion reaction concluded from the binding constants at different temperatures. The inclusion of β- CD and nitrosation product from orange IV enhanced obsorbance, thus increased the sensitivity of the determination. Beer＇s law was obeyed over the range of 0 ~ 0. 82 μg· mL^-1 for nitrite ion.