应用斐林试剂与碘液时的几点注意问题     

单林兰 《中学生物学》2006,22(11):40-40

实验原理：淀粉和蔗糖为非还原性糖，它们在酶的作用下，都能水解成还原性糖，还原性糖能与斐林试剂发生氧化还原反应，生成砖红色的氧化亚铜沉淀。  相似文献   

《中文自修》袖珍试卷 上海民办张江集团学校语文组 初三语文试卷     

《中文自修》2011,(12)

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分光光度法测定海带中的碘   总被引：3，自引：0，他引：3  

谢少艾  陈虹锦  马荔  张卫 《实验室研究与探索》2005,24(7):16-17

讨论了用Fe^2＋-邻二氮菲体系分光光度法间接测定海带中微量碘含量的方法。本实验以NH4Fe（SO4）2作为氧化剂，使用邻二氮菲作为显色剂，通过测得吸光度与Fe^2＋溶液浓度成线性关系，可间接测定海带提取溶液中I^-的浓度。该法具有准确度高，重现性好，简便快速的特点，是测定海带中微量碘的一种较理想的方法。  相似文献   

如何避免碘遇淀粉变蓝后又褪色     

刘忠慧 《生物学教学》2004,29(7):35-35

在用碘检验淀粉的实验中,常出现碘使淀粉变蓝后,过一段时间又褪色的情况。主要是碘与淀粉形成的络合物不稳定易分解,所以褪色。实验时,在碘液中加少量的盐酸或变蓝后加少量的盐酸,就会避免褪色。  相似文献   

检验Br^—和I^—的实验研究     

胥光勇 《化学教学》1994,(1):10-13

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Investigation of iodine concentration in salt,water and soil along the coast of Zhejiang,China     

陆颖理  王宁荐  朱岚  王国兴  吴晖  匡琳  朱文明 《Journal of Zhejiang University. Science. B》2005,6(12):1200-1205

Objective: We aim to describe the environment iodine concentration in salt, water and soil along Zhejiang Province coast in the China foreland. It will be helpful for us to judge whether this area is insufficient in iodine and universal iodized salt is necessary or not. Methods: We collected iodized salt samples, drinking water samples (tap water in the towns, and well water or spring water in the villages), water samples from different sources (ditches, lakes, rivers) and soil samples through random sampling in June, 2005. Salt, water and soil iodine was detected by arsenic-cerium redox method. Statistical analysis was expressed as mean±SEMby Windows SPSS 13.0. Results: (1) The iodine concentration in salt was 27.9±4.33 mg/kg (n=108). (2) Seventy-five water samples were collected. The water iodine value was 0.6～84.8 μg/L (mean of 11.66 μg/L). The watershed along the Qiantang River has significantly higher iodine content than the water in Lin'an in mountain area (P＜0.01). The iodine content and mean iodine content of tap water, well or spring water and natural water sources were 4.30±2.43 μg/L (n=34), 23.59±27.74 μg/L (n=19)and 12.72±10.72 μg/L (n=22) respectively. This indicated that among environmental water sources, the ditch iodine content was the highest with river water iodine being the lowest (P＜0.01). (3) Soil iodine value was 0.11～2.93 mg/kg (mean of 1.32 mg/kg).Though there was no statistical difference of soil iodine in different districts (P=0.131), soil iodine content correlated positively with water iodine content. Conclusion: Iodine concentration in salt accords with national policy of adding iodine in salt. Foreland has more iodine in water than mountain area. The data reflected that water and soil iodine in foreland area was not high, which suggests universal iodized salt should be necessary. Environment iodine has relatively close association with pollution.  相似文献   

碘酸钙溶度积的测定     

杨水彬  倪春林 《黄冈师范学院学报》1995,(3)

采用碘量法测定碘酸钙溶度积常数，方法十分简单，测定结果满意．  相似文献   

纳米尺度AgBr/I乳剂颗粒的光电子衰减行为     

刘霁  宋磊  岳军 《浙江大学学报(A卷英文版)》2004,(2):81-87

本文以鱼明胶为保护介质,在不同的鱼明胶-溴化银比值下,采用双注法制备AgBr/I纳米颗粒乳剂,以TEM观测颗粒形态,据此统计得出该乳剂中AgBr/I纳米颗粒平均粒径(d)及粒径分布系数(|±σ|/d).鱼明胶-溴化银比值在0.31 g/mmol-0.62 g/mmol范围内,颗粒平均粒径仅有微小变化,但粒径分布系数随该比值的增大而减小,表明颗粒均一性提高.采用微波光导法对该纳米尺度AgBr/I乳剂颗粒的光电子衰减过程进行测试,结果表明,纳米尺度Ag-Br/I乳剂颗粒的光电子衰减过程为双组分,即初始快衰减和随后慢衰减,其衰减过程皆符合一级动力学规律.该纳米尺度乳剂颗粒光电子寿命较常规乳剂颗粒明显缩短.  相似文献   

快炒家常菜     

徐娇 《启蒙(3-7岁)》2011,(8):41

双耳金仁原料:木耳20克,银耳20克,油菜50克,鸡蛋黄2个,甜杏仁、精盐、料酒、姜末、植物油适量。制作过程:⒈将木耳、银耳分别泡发,洗净,切成稍小些的片,放入开水锅中焯至八成熟,捞出沥水。油菜洗净,切成段。⒉锅中放油烧热,倒入打散的鸡蛋黄翻炒片刻,盛出。⒊锅中留油少许,下入姜末炝锅,倒入  相似文献   

让宝宝爱上蔬菜     

徐娇 《启蒙(3-7岁)》2011,(9):42

鲜蔬果味小炒原料:黄瓜100克,胡萝卜1根,鸡蛋2个,葡萄干20克,西瓜丁、桃丁、精盐、橄榄油适量。制作过程:1.将黄瓜、胡萝卜洗净,去皮,切成丁。鸡蛋打入碗中,搅散。葡萄干洗净。2.炒锅放少许油,烧热,倒入鸡蛋液,炒熟后弄成碎块,盛出。  相似文献