１引言 碘是人体必需营养元素之一，成年人缺碘会导致甲状腺机能亢进，患大脖大病，小孩缺碘会导致甲状腺发育不良，生长发育迟缓，智力低下，甚至于痴呆。食盐中加碘是防止碘缺乏病最主要、最经济、最简单的方法。测定微量碘最常用的方法是重铬酸钾法，也有用催化光度法、离子 1 INTRODUCTION Iodine is one of the essential nutrients of the human body. Idiopathic iodine in adults can lead to hyperthyroidism and big neck disease. Child iodine deficiency can lead to hypothyroidism, growth retardation, mental retardation and even dementia. Iodized salt is to prevent iodine deficiency disorders the most important, most economical and easiest way. Determination of trace iodine is the most commonly used method of potassium dichromate, but also useful catalytic spectrophotometry, ions