论文总字数：15532字

摘 要

因为受到工业污水的影响，市场上的淡水鱼有重金属超标的可能，这对普通人群的身体健康产生风险。本课题对南京市场上在售的淡水鱼进行抽样调查，对不同种类的淡水鱼中总汞和甲基汞的含量进行分析，了解汞污染对人体的危害。

从南京市场上购买四种淡水鱼：鲤鱼、草鱼、鳙鱼和黑鱼。将其肌肉组织碾磨细碎，通过高效液相色谱-紫外消解-原子荧光（HPLC-UV-AFS）测定其中所含的总汞和甲基汞。通过测定标准物质来确定方法的可靠性。鱼类样品加入4 mL硝酸和2 mL氧化氢在150 ℃微波消解20分钟，离心15分钟，取上清液稀释测定总汞。另一部分样品用0.6% L-半胱氨酸萃取震荡24 h，取上清液稀释测量甲基汞。鱼类总汞和甲基汞含量由高到低分别是黑鱼，鳙鱼，草鱼，鲤鱼。鱼类所含汞含量与其食物链位置有关，草食性鱼所含汞均较低，小于肉食性鱼类。甲基汞占总汞含量约为80%，甲基汞的含量与总汞成正比。本实验所用方法简便，快速，有一定可靠性，可用于淡水鱼类总汞和甲基汞的测量。实验结果表明南京市场上四种常用食用淡水鱼的总汞和甲基汞含量均低于我国国家淡水鱼食品卫生标准，可放心食用。

关键词：淡水鱼 总汞 甲基汞 HPLC-UV-AFS

Abstract

Suffered from industrial pollution, it is highly likely that the content of heavy metal existing in freshwater fish in the market may exceed the standard, which may generate risks to the health of ordinary people. This project aims at making a sampling survey on the freshwater fish sold in Nanjing market, and analyzing total mercury and methylmercury existing in various kinds of freshwater fish so as to learn the harmful effects of mercury pollution on the human body.

Four kinds of freshwater fishes were purchased in Nanjing market: carp, grass carp, bighead carp and snakehead. Then their muscle tissues were ground to measure the content of total mercury and methylmercury by HPLC-UV-AFS. And, to ensure the reliability of the method, the reference materials are measured. To do this, the samples were added 4 mL nitric acid and 2 mL hydrogen peroxide in fish samples, microwaved for 20 minutes at 150℃, and treated in centrifuge for 15 minutes. Then the supernatant dilution liquid can be measured for total mercury, while the supernatant dilution liquid from another sample after extracted with 0.6% L- cysteine, and shaken for 24 hours can be used to measure total mercury. The content of the total mercury and methylmercury in fishes, from the highest to the lowest, are blackfish, bighead, grass carp and carp. The mercury content of fish is linked to its position on the food chain. The mercury found in herbivorous fishes was less as compared to carnivorous ones. The method of this experiment is simple, rapid, and reliable to some degree，so it can be used to measure the methylmercury and the total mercury of freshwater fish. The experiment result shows that the total mercury and methylercury of the four kinds of freshwater food fishes in Nanjing market is lower than our national Hygienic standard for freshwater fish, so they are safe to eat.

Key Words: freshwater fish; total mercury; methylmercury; HPLC-UV-AFS

摘 要 I

Abstract II

第一章 绪 论 1

1.1研究背景 1

1.1.1汞的基本理化性质和主要来源 1

1.1.2汞的危害 1

1.1.3汞的转移循环 2

1.2汞分析方法 2

1.2.1原子吸收光谱法 2

1.2.2原子荧光光谱法 3

1.2.3汞分析检测联用技术 4

1.2.4其他分析法 5

1.3本课题研究的目的及意义 5

第二章 鱼肉中总汞含量分析 6

2.1 引言 6

2.2实验部分 6

2.2.1实验主要仪器 6

2.2.2实验主要试剂 6

2.2.3仪器工作条件 7

2.2.4试剂及标准的配置 7

2.2.5鱼肉样品处理方法 7

2.3结果与讨论 8

2.3.1实验结果 8

2.3.2讨论 9

第三章 鱼肉中甲基汞含量分析 10

3.1引言 10

3.2实验部分 10

3.2.1实验主要仪器 10

3.2.2实验主要试剂 10

3.2.3仪器工作条件 11

3.2.4试剂及标准的配置 11

3.2.5鱼肉样品中甲基汞含量的测量 12

3.3结果与讨论 13

3.3.1实验结果 13

3.3.2讨论 15

第四章 结论与展望 16

参考文献 17

致 谢 19

1. 绪 论

1.1 研究背景

汞在自然界分布极广，在科学研究和工业生产中都是重要原料，在人类的生产生活中起着重要作用。但汞同样危害着人类和各种高等生物的健康^[1,2]。世界上最大的汞排放国家就是我国。排放的汞中90%都会进入生态循环系统^[3]。因此，汞污染具有一定流动性，也成为了全球性的污染问题。汞污染和汞中毒事件也在全球接连发生。因此，水环境^[4]，水产品^[5]这些人类日常接触或者使用的方面，尤其是食用淡水鱼类，成为汞污染检测研究的关注点之一。

请支付后下载全文，论文总字数：15532字