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摘要：本论文采纳分光光度计仪器，应用碘酸钾在呈现PH<7的情况下容易被还58-原产生I2，同时会遇淀粉变蓝的这一原理，并将用于测定食盐中碘含量的一系列条件通过反复测试检查以获得相对优化的条件，从而可得到相对精确食盐中的碘含量的测试结果。初步可知，显色时长、KI03标液的剂量、饱和KI溶液的剂量、饱和淀粉指示剂的使用剂量、H2SO4溶液的剂量和浓度等要素对本实验会产生一系列的影响，所以要对各条件都进行具体的探讨。结论:通过数几次体系反应测试后，波长580nm对应的吸光度值最大而且较稳固，最佳的显色时间为15分钟。当使用的碘酸钾中碘含量的浓度在 0μg／mL到2μg／mL范畴内时，经过分光光度计所测得的数据呈现出较好的线性关系曲线，该曲线的相关系数计算得 0.9998，相对平均偏差为 0．218％。通过尽可能使试验条件变成最佳，操作尽可能简洁明了，实验结果尽可能准确可靠。本论文实验简便和安全，结果与国标方法无差异，而且避免了国标滴定方法中的人为判断因素影响，适用于测量食盐中的碘含量。41005
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毕业论文关键词：食盐；碘酸钾；改进；722分光光度计；
Study on analysis of iodine content in salt
Abstract: This thesis adopts points spectrophotometric instrument and application of potassium iodate in PH<7 easily reduced I2. At the same time will encounters starch to change the principle of blue, and will be used for the determination of iodine content of salt in a series of conditions through repeated tests to obtain relatively optimal conditions, which can be relatively accurate in salt iodine content of test results. Preliminary knowable, color, long and dose KI03 standard solution, saturated dose of Ki solution, saturated starch indicator, the dosage and H2SO4 solution dosage and concentration and other factors on the will produce a series of influence, so to specific discussion of different conditions. Conclusion: by the number of times the reaction system test, 580nm corresponding absorbance value maximum and more stable, the best color time for 15 minutes. When using potassium iodate iodine concentration in 0ug / ml and the to 2ug / ml category in, after a spectrophotometer measured data shows good linear relationship curve, the curve of correlation coefficient calculated 0.9998, the average relative deviation is 0.218%. As far as possible to make the test conditions to be the best, the operation as simple as possible, as far as possible, the results of the experiment as accurate and reliable. The experiment is simple and safe, and the result is no difference with the national standard method, and it can avoid the influence of the human judgment factor in the national standard titration method.This is great for measuring the salt iodine content.
KeyWords：salt; potassium iodate; improvement; 722 spectrophotometer;
目录
1 前言 1
1.1研究食盐中碘含量分析研究课题的重要意义 2
1.2国内食盐质量标准的趋势及碘含量的指标 2
1.3食盐中碘含量的检测方法的介绍 4
1.3.1分光光度法 5
1.3.2石墨炉原子吸收光谱法 5
1.3.3均三溴偶氮胂褪色分光光度法测定食盐中碘 5
1.3.4结晶紫一草酸体系光度法测定食盐中的碘 5
1.4分光光度法的原理 6
2 实验内容 6
2.1 试剂与材料 6
2.2 实验仪器 7
2.3 实验原理 7
2.4 实验方法 7
2.4.1 测定波长的选择 8
2.4.2 显色时间的选择 8