1-(2-吡啶偶氮)-2-萘酚(PAN)褪色光度法测定食盐中碘的研究

Study on Determination of Iodine in Edible Salt with 1-(2-pyridylazo)-2-Naphthol(PAN)Fading Spectrophotometry

在酸性介质中,溴化钾存在下,碘酸根对1-(2-吡啶偶氮)-2-萘酚(PAN)有褪色作用,且褪色程度与碘酸根的量有关,从而建立了碘的光度测定新方法。方法的最大吸收波长在430nm处,碘定量测定的线性范围为0～18μg/25mL。方法操作简单,快速、重现性好,用于加碘食盐中碘的测定,结果满意。

In acid media and with the existence of potassium bromide,iodate radical has fading effect on 1-（2-pyridylazo）-2-naphthol（PAN）,whose fading degree is relevant to the quantity of iodate radical, thus new determination method of spectrophotometry is established.The maximum absorption wave length in the method is at 430nm and quantitative determination linear range of iodine is 0-18μg/25mL.The method,simple and quick to operate and with good reproductivity, is applied in the iodine determination of iodized edible salt with satisfactory results achieved.