以十二烷基苯磺酸钠为增溶剂阻抑催化光度法测定痕量碘

Inhibitory Catalytic Spectrophotometric Determination of Trace Iodine Using Dodecyl Benzene Sulfonic Acid Sodiumsalt as Solubilizer

在 p H=4 .5的 HAc- Na Ac介质中 ,痕量碘能阻抑以 2 ,2′-联吡啶为活化剂 ,阴离子表面活性剂十二烷基苯磺酸钠 (SDBS)为增溶剂 ,银催化过硫酸钾氧化天青 ( )的褪色反应 ,据此建立了测定痕量碘的阻抑催化动力学光度分析新方法。本法检出限为 3.6× 10 -3 mg/ L ;线性范围为 0 .0 2— 0 .16 mg/ L。用于紫菜、海带中痕量碘测定 。

A new inhibit catalytic spectrophotometric method for the determination of trace iodine has been developed in HAc-NaAc(pH=4.5)buffer medium. This method is based on the iodide can inhibit the azure(Ⅱ) discoloration reaction with potassium persulfate catalyzed by silver in the presence of 2,2′-dipyridyl as an activator and the dodecyl benzene sulfonic acid sodiumsalt (SDBS) as a solubilizer.The detection limit is 3.6×10 -3mg/L,the linear range of determination is in the range of 0.02- 0.16mg/L for iodine.This method has been used to determine trace iodine in laver and kelp sample with satisfactory results.