食品中多氯联苯的安全评估测定

范文编号:HG102  范文字数:11485,页数:25

摘要：多氯联苯是一种全球性毒性污染物，由于多氯联苯的理化性质稳定，非常难以降解(其半衰期长达40年左右)，加上其长期积累以及其中某些异构体和同族体高度的生物富集性和毒性，PCBs已造成了全球性的污染。现已证明PCBs对皮肤、肝脏、胃肠系统、神经系统、生殖系统、免疫系统的病变甚至癌变都有诱导效应。根据资料，发现很多学者对多氯联苯的动物性实验已经做了很充足的研究，在对多氯联苯的微生物实验进行的很少。因此，决定研究观察多氯联苯对微生物生长是否有影响。观察不同浓度的PCB105，PCB118，PCB157和PCB169对细菌的抑制性能的影响，将含有一定量多氯联苯的纸片，平贴在已经接种被测细菌的琼脂培养基上，将平皿置于37℃下培养48小时后观察结果。结果说明了多氯联苯对细菌的生长是有抑制作用的，但是这种抑制作用并不是很明显。其中80ppb的PCB169对细菌的抑制作用较其他几种来说影响比较大。因此，PCBs不能很好的抑制细菌的生长，而且可以在细菌中滞留，危害人体的健康。

关键词: 多氯联苯;安全;评估;测定;毒性; 结构; 来源;细菌

Study of PCBs safety evaluation in food
Abstract: Polychlorinated Biphenyls is a global toxic pollutants, As the stability of physical and chemical properties of PCBs, Is very difficult to degrade(Its half-life of about 40 years), Coupled with its long-term accumulation as well as some of the isomers and congeners with a high degree of bio-accumulation and toxicity, Has resulted in a global pollution. Has proven to PCBs on the skin, liver, gastrointestinal system, nervous system, reproductive system, immune system diseases and even cancer are in maize. According to the information, Many scholars of the PCBs found in animal experiments have been done ample research, PCBs in the experiment of small micro-organisms. Therefore, Decided to study whether the observed impact of PCBs on the microbial growth. Observation of PCBs in the PCB105, PCB118, PCB157 and PCB169 on the inhibition properties of bacteria, PCB containing a certain amount of paper, Flat stick has been tested bacteria inoculated agar medium, The plate at 37 ℃ for 48 hours under observation. Results suggest that PCBs have on the growth of bacteria inhibition, But this inhibition is not very clear. In the four PCBs , 80ppb of PCB169 on the inhibitory effects of several other bacteria is the greatest impact. Therefore,PCBs are not well inhibited the growth of bacteria,And can stay in bacteria, Harm to human health.

Keywords: PCBs;safety; assessment; Determination; toxicity; Frame; Source; Bacterial

目录
   中文摘要........................................................ I
   英文摘要........................................................II
   目  录........................................................ III
 1  绪论........................................................ .1
 1．1 PCBs的定义、结构和性质................................ .1
 1．2 食品中多氯联苯的来源.................................... 4
 1．3 PCBs的毒性 .............................................6
 1．4 多氯联苯污染土壤的微生物.................................8
 1．5 多氯联苯的降解方法................................... ...10
 2 实验部分.......................................................11
 2.1 研究的主要内容......................................... ...11
 2.2 材料.................................................... ..11
 2.3 方法.................................................. ....12
 2.4 结果与分析.................................................13
 4 讨论与展望................................................. ....16
 4．1 讨论......................................................16
 4．2 展望................................................ ......18
 致 谢.......................................................... ..20
 参考文献........................................................21

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