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摘要： 本文采用分光光度法研究了二乙基二硫代氨基甲酸钠与铜在碱性环境中的显色反应和邻菲罗啉与铁在乙酸-乙酸钠缓冲溶液中的显色反应，确定了最佳试验条件，提出一个灵敏度高，简便、快捷测定微量铜、铁的分光光度法。结果表明：在测铜的方法中，我们选择在pH约为9.0的氯化铵-氢氧化铵缓冲溶液中进行，此时最大吸收波长位于440nm处，最佳显色时间为5min。回归方程为：Y=0.06404X，线性范围为0.2-5ug。而在测铁的方法中，我们选择在pH约为5.0的乙酸-乙酸钠缓冲溶液中进行，此时最大吸收波长位于510nm处，最佳显色时间为10min。回归方程为：Y=0.12182X,线性范围为0.4-1.6ug/ml。此法用于粮食及饲料中微量铜、铁的测定，获得了满意的效果。36400
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毕业论文关键词：铜；铁；分光光度法；二乙基二硫代氨基甲酸钠；邻菲罗啉；饲料
The analysis and research on the content of copper and iron in the food and feeds
Abstract: This article makes use of the spectrophotometric method to research the chromogenic reaction on the sodium diethyl dithiocarbamate and copper in the alkaline condition and we also research the chromogenic reaction on the phenanthroline and iron in the buffered solution of acetic acid-sodium acetate. Thus the best experiment conditions were concluded, which will be a high sensitivity, simple and fast spectrophotometric method of copper and iron testing. Results show that determining the content of copper is fit for the condition of the buffered solution of ammonium chloride-ammonium hydroxide which the pH value is about 9.0, the maximum absorption wavelength is located at 440nm and the best reaction time is 5 minutes.The regression equation is: Y=0.06404X，the linearity range is 0.2-5ug. And determining the content of iron is fit for the condition of the buffered solution of acetic acid-sodium acetate which the pH value is about 5.0, the maximum absorption wavelength is located at 510nm and the best reaction time is 10 minutes.The regression equation is: Y=0.12182X, the linearity range is 0.4-2.0ug/ml. This method can be used for the testing of the content of copper and iron in the food and feeds, and we come off the satisfactory results.
Keywords：copper; iron; spectrophotometric method; sodium diethyl dithiocarbamate; phenanthroline; feeds
目录
1 前言 1
1.1研究粮食及饲料中铜、铁离子检测的重要意义 1
1.2粮食及饲料中铜、铁含量的检测方法的介绍 2
1.2.1 分光光度法 2
1.2.2 石墨炉原子吸收光谱法 3
1.2.3 电感耦合等离子体原子发射光谱法 3
1.2.4 火焰原子吸收光谱法 3
1.3分光光度法的原理 4
1.4分光光度法的分类 5
1.4.1 常规分光光度法 5
1.4.2 催化动力学分光光度法 5
2 实验内容 6
2.1 试剂与材料 6
2.2 实验仪器 6
2.3 实验方法 7
2.3.1 溶液的配制 7
2.3.2 标准曲线的绘制 8
2.3.3 未知样品的测定 10
3 结果与讨论 13
3.1 金属离子检测工作条件的确定 11
3.1.1 最大吸收波长的确定 13
3.1.2 显色剂用量的选择 16
3.1.3 适宜酸碱度的测定 18
3.1.4 显色时间的确定 20
3.2 粮食及饲料中铜、铁离子的检测方法 22
3.2.1 工作曲线的绘制 22
3.2.2 样品测定结果 25
4 结论 27