【作者】 刘颖；

【导师】 刘立侠； 陈珊；

【作者基本信息】 东北师范大学 ， 植物学， 2010， 博士

【摘要】 碘是人体中必不可少的微量元素之一,可以维持基本生命活动,维持脑垂体的生理功能,促进身体和大脑发育。人体长期摄入不足可引起碘缺乏病,如地方性甲状腺肿和地方性克汀病等。分析和研究不同生物样品特别是中国人饮食结构中碘元素的含量,推断人体从食物中碘的摄入量,对确定合理碘的需求对人体健康的重要性有一定的指导意义。碘的化学特征不稳定,是较难检测的元素之一。由于生物材料中碘的含量很低,化学成分复杂,且个体差异大和干扰成分多,因此建立一种准确性高、稳定性好、快速、灵敏的微量碘测定方法具有十分重要的意义。目前微量碘的检测一般采用手工方法,这种方法因难以严格控制反应温度和反应时间导致测定结果不稳定,实验过程中各种干扰因素及碘的污染问题也是分析准确度差的一个重要原因。本研究的目的是研究和建立顺序注射催化分光光度微量碘仪器分析方法,消除手工检测的人为局限,用以检测不同来源生物样品中碘的含量,为目前加碘食盐浓度的调整和碘营养监控提供一定的科学依据。本研究采用顺序注射溶液配送原理,应用程控注射泵方案推动载液和试剂,设计微量碘分析仪器。采用自行研制的16孔程控选择阀,实现顺序注射进样、流动配送、停留稳定和停留检测的自动化成,建立了顺序注射微量碘检测方法。其特点是测定条件稳定、分析速度快、线性范围宽、灵敏度高,检测自动化,可准确快速检测生物材料中的微量碘,具有很好的应用前景。本方法线性范围为15～600μg/L,检出限为5.01μg/L(n=11),回收率为94.1%～105.1%。对国家标准参考物质(GBW09109和GBW09110)的测定结果在给定的标准值范围内。应用本仪器及方法检测了不同来源的生物样品中碘的含量。检测的哈尔滨市售27种食物样品(肉蛋、粮食、蔬菜和水果等)中碘含量在10～2000μg/kg不等,其中鲜海带含碘量最高为2424.2μg/kg,肉蛋高于粮食,蔬菜水果含碘量较低。根据检测结果,结合人们日常生活各种食物的摄入量,判断目前哈尔滨市区人群每天碘的摄入总量,略高于国际组织对碘需要量的推荐标准(150μg/d),主要是从盐中摄入的碘浓度(35±15mg/kg)大于从各种食物中摄入碘的总量。建议居民应适量减少碘盐的摄入,政府有关部门应根据实际情况适当调整碘盐浓度,有助于将碘的摄入量维持在正常水平。本实验检测了哈尔滨市部分育龄妇女、孕妇和学龄儿童的尿样,食用盐样和饮用水样。尿碘范围在70-370μg/L之间,统计学分析育龄妇女与孕妇的尿碘及孕妇与学龄儿童的尿碘之间有显著性差异,且孕妇与育龄妇女的尿碘水平普遍比学龄儿童低。调查结果判断部分孕妇的碘营养状况还存在一些问题,鉴于孕妇生理特点的特殊性,应重点加强此部分人群的碘营养监测与保健工作。检测的食用碘盐浓度为31.2mg/kg,饮用水碘浓度为5.6μg/L。本实验检测了海藻中的生物碘含量,研究海藻在不同的浸溶条件下碘的溶出情况。在浸泡海带的过程中,浸溶出的海带碘量与浸溶时间的长短、浸溶水量、浸溶温度及浸溶液的酸碱度均有一定的关系,而浸溶时间与浸溶温度影响最为显著。建议可利用海藻碘作为一种生物活性碘源,通过在土壤和植物生长过程中的使用,放大环境中碘的含量,达到提高作物碘含量的目的,使碘在环境中的生物地球化学转移成为可能,探寻更为高效、安全的人体自然补碘新途径。更多还原

【Abstract】 Iodine is one of essential micronutrients in the human body, which can maintain basic life activities and the physiological functions of the pituitary gland and promote the physical and brain development. Long-term insufficient iodine intake, such as endemic goiter and endemic cretinism, can cause iodine deficiency disorders. Analysis of iodine content in different biological samples and the Chinese people’food in particular and speculation of the iodine intake of the body from food can provide some guidance for determining the significance of reasonable iodine need for human health. Iodine is one of the elements difficult to detect because of its unstable chemical characteristics. Iodine in biological materials has its low content, complex basic ingredients, large individual differences and interfering with many components. Therefore, it is of great significance to develop a highly accurate, stable, rapid and sensitive method for trace iodine determination. At present, microamount of iodine is commonly detected by manual method, by which the reaction temperature and reaction time are difficult to be controlled strictly. Thus, this method can lead to unstable measurement results. Besides, various interference factors in experimental process and iodine pollution are important reasons for poor accuracy. In the present study, we aimed to investigate and establish the instrumental analyzing method of the sequential injection catalytic spectrophotometric determination of microamount of iodine, to eliminate the artificial limitations of manual detection and to detect iodine content in biological samples from different sources, which can provide a scientific basis for the adjustment of iodized salt concentration and monitoring of iodine nutrition.In the present study, the analyzing instrument for microamounts of iodine determination was designed on basis of sequential injection solution delivery principle and by using the programmable syringe pump to push carrier liquid and reagents. The self-designed 16-hole program-controlled selection valve was used to achieve automation of sequential injections of the samples, mobile delivery, residence stabliztion and residence testing. The sequential injection detection of microamounts of iodine was established which was characterized by stable determination condition, rapid analysis, broad linear range, high sensitivity, automatic detection, accurate and rapid detection of iodine in biological samples, and had good application prospects. This method had its linear range of 15~600μg/L, the detection limit of 5.01μg/L (n=11), recovery of 94.1%~105.1% and the determination results of the national standard reference material (GBW09109 and GBW09110) in a given standard value range. The detection of iodine content in biological samples from different sources showed that the iodine contents of 25 types of food (from Harbin) samples (Meat, eggs, grain, vegetables, fruits, etc.) varied from 10μg/kg to 2000μg/kg, with a highest iodine content of 2424.2μg/kg in fresh Kelp, higher iodine content in meat and eggs than grain, a low iodine content in fruits and vegetables. According to the detection results and people’s daily intake from various food, we determined that total daily intake of iodine of the urban population in Harbin was slightly higher than the recommended amounts of the normal population (150μg/d). The iodine intake from salt (35±15 mg/kg) was greater than from other types of food, therefore, reducing the intake of iodized salt, or declining the iodine content of iodized salt by government appropriately based on actual situation were proposed and contributed to keep iodine intake normal.The urine, salt samples of several women of childbearing,pregnant women and school-age children were determined and the result showed that urine iodine range was 70-370μg/L.The urine iodine values of women of childbearing group and pregnant woman group as well as pregnant women and school-age children were statistically analyzed and the result showed there were significant differences between both groups and the urine iodine of pregnant women and childbearing women were lower than that of school-age children. The investigation showed that there were still some problems with the iodine nutrition status of some pregnant women. Given the special physiological characteristics of pregnant women, the odine nutrition surveillance and health care of this part of the population should be strengthened. The urine content of salt was 31.2 mg/kg.The urine content of drinking water was 5.6μg/L.The biological iodine in the seaweed was dected by our instrument and method. The dissolution of iodine in the seaweed at different soaking conditions was studied. We found that during kelp soaking, the amount of soaked iodine was associated with soaking time, the volume of soaking water, soaking temperature and the pH value of soaking solution, and the effect of the soaking time and soaking temperature on the amount of soaked iodine were most remarkable.The seaweed iodine can be recommended as an active biological iodine source.The use of seaweed iodine in the soil amplifies the iodine content of the environment, which increases the feasibility of bio-geochemical study on iodine in the environment, elevates the iodine in the crop, and contributes to explore a more efficient and safe way of iodine supplement for human bodies.更多还原