IO_3^--I^--吖啶红-聚乙烯醇体系分光光度法测定食品中微量碘  

Spectrophotometric Determination of Iodine with the System of IO_3^--I^- Acridine Red-polyvinyl Alcohol

作　　者：彭金云[1] 唐宁莉[1] 

机构地区：[1]桂林工学院材料与化学工程系,广西桂林541004

出　　处：《食品科学》2007年第4期283-284,共2页Food Science

摘　　要：在磷酸介质中,IO_3^-氧化I^-离子形成I_3^-络阴离子,I_3^-络阴离子进一步与吖啶红(AR)阳离子形成离子缔合物,在聚乙烯醇存在下,溶液清亮。以试剂空白参比,波峰λ_(max)位于584nm处,吸光度A与IO_3^-的浓度成正比。表观摩尔吸收系数ε=5．27×10~5L/mol·cm,IO_3^-含量为0～7．0μg/25ml时服从比尔定律。方法用于碘盐和生物样品检测,结果令人满意。A highly sensitive spectrophotometric method was developed for the determination of trace amounts of Iodine based on the oxidation of I^- to I3^- by IO3^-and the further reaction of I3^-with acridine red to form the ion-association complex [AO] [L]in dilute phosphoric acid solution. In the presence of polyvinyl alcohol the solution is transparent. The λmax of the absorption spectrum is 584 nm against reagent blank. It was discovered that the absolute value of the λmax is proportional to the IO3^-concentration. The molar absorptivity is ε =5.27 × 10^5 L/mol · cm for normal assay at 584nm. Beer＇s law is obeyed in the range of 0-7.0μ g/25ml. The method has been applied to the determination of iodine in biological samples with satisfactory results.

关 键 词：碘 吖啶红 离子缔合物 分光光度法 

分 类 号：Q657.32[生物学—生物物理学]