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摘要：随着饮食安全越来越受重视，食物和饮用水中亚硝酸盐的含量也已经成为了大家关注的焦点。本文使用了722型分光光度计，采用盐酸萘乙二胺法，在弱酸性条件下，亚硝酸盐与对氨基苯磺酸发生重氮化反应，再与盐酸萘乙二胺偶合生成紫红色偶氮染料，从而对隔夜菜和千滚水中亚硝酸盐含量进行分析研究。显色15~30分钟，生成染料颜色的深浅与亚硝酸盐含量成正比。在波长539nm处，亚硝酸盐含量与吸光度有着最大吸收波长。亚硝酸盐测定范围0.014~1.130μg/mL，线性方程为y=0.0133x+0.0283，相关系数r=0.9994，测定下限为0.046μg/mL。利用此方法测定放置不同时间的隔夜菜和烧开不同次数、不同时间的千滚水中亚硝酸盐含量的变化。测定结果表明：隔夜菜中亚硝酸盐含量随着放置时间的增长而增长；千滚水会因为煮沸次数和煮沸时间的增加而使亚硝酸盐含量增加。两者加标回收率在94%~103%之间。此法简单方便、实用性强、准确度高，是测定亚硝酸盐含量的好方法。27788
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毕业论文关键词：亚硝酸盐；盐酸萘乙二胺法；隔夜菜；千滚水
The analysis and research of the NO2-content in the food and drinking water
Abstract：As people pay more and more attention to food security, the nitrite content in food and drinking water has become the focus of attention. This article uses the type 722 spectrophotometer, using hydrochloric acid naphthyl ethylenediamine method. The method is based on the diazo-reaction of sulfanilic acid with nitrite in weak acid, and then coupled with N-ethylenediamine generated purple azo dyes. This method is used to analysis and research the nitrite content in overnight food and thousands of boiling water. Color for 15 minutes, the depth of dyes color is proportional to the content of nitrite. At the wavelength of 539 nm, nitrite content has a maximum absorption wavelength. Nitrite in 0.014 ~ 1.130μg/mL， has a linear function linear equation is y = 0.0133x+0.0283, correlation coefficient r = 0.9994,limit of determination is 0.046μg/mL. This method has been applied to the determination the change of nitrite content in overnight food storaged at different times and thousands of boiling water boiled at different times and times. The determination results show that the nitrite content in overnight food will increase while the increasing of storage time; the nitrite content in thousands of boiling water will increase while the increasing of boiling times and boiling times. The standard addition recovery rate is between 94%~103%. This method is simple, convenient, strong practicability, high accuracy, is a good method for determination of nitrite content.
Keyword: Nitrite; Hydrochloric acid naphthyl ethylenediamine method; overnight food; thousands of boiling water
目录
1 前言 1
1.1 亚硝酸盐 1
1.1.1 亚硝酸盐的性质及用途 1
1.1.2 饮食中亚硝酸盐来源 2
1.1.3 亚硝酸盐中毒 2
1.2 亚硝酸盐测定的方法 3
1.2.1 分光光度法 3
1.2.2 色谱法 3
1.2.3 电化学法 4
1.2.4 毛细管电泳法 4
2 实验部分 5
2.1 实验原理 5
2.2 样品材料 5
2.3 实验内容 5
2.3.1 实验仪器与试剂 5
2.3.2 亚硝酸钠标准溶液的标定（0.1000mol/L） 5
2.3.3 最大吸收波长的确定 6
2.3.4 亚硝酸盐标准曲线测定 6
2.3.5 样品处理 6
2.3.6 样品中亚硝酸盐含量测定 6
3 结果及讨论 6
3.1 亚硝酸盐标准溶液的标定结果 6