食品中多氯聯(lián)苯的安全評估測定

化工論文編號:HG102  論文字?jǐn)?shù):11485,頁數(shù):25

目錄
   中文摘要........................................................ I
   英文摘要........................................................II
   目  錄........................................................ III
 1  緒論........................................................ .1
 1．1 PCBs的定義、結(jié)構(gòu)和性質(zhì)................................ .1
 1．2 食品中多氯聯(lián)苯的來源.................................... 4
 1．3 PCBs的毒性 .............................................6
 1．4 多氯聯(lián)苯污染土壤的微生物.................................8
 1．5 多氯聯(lián)苯的降解方法................................... ...10
 2 實(shí)驗(yàn)部分.......................................................11
 2.1 研究的主要內(nèi)容......................................... ...11
 2.2 材料.................................................... ..11
 2.3 方法.................................................. ....12
 2.4 結(jié)果與分析.................................................13
 4 討論與展望................................................. ....16
 4．1 討論......................................................16
 4．2 展望................................................ ......18
 致 謝.......................................................... ..20
 參考文獻(xiàn)........................................................21

摘要：多氯聯(lián)苯是一種全球性毒性污染物，由于多氯聯(lián)苯的理化性質(zhì)穩(wěn)定，非常難以降解(其半衰期長達(dá)40年左右)，加上其長期積累以及其中某些異構(gòu)體和同族體高度的生物富集性和毒性，PCBs已造成了全球性的污染。現(xiàn)已證明PCBs對皮膚、肝臟、胃腸系統(tǒng)、神經(jīng)系統(tǒng)、生殖系統(tǒng)、免疫系統(tǒng)的病變甚至癌變都有誘導(dǎo)效應(yīng)。根據(jù)資料，發(fā)現(xiàn)很多學(xué)者對多氯聯(lián)苯的動物性實(shí)驗(yàn)已經(jīng)做了很充足的研究，在對多氯聯(lián)苯的微生物實(shí)驗(yàn)進(jìn)行的很少。因此，決定研究觀察多氯聯(lián)苯對微生物生長是否有影響。觀察不同濃度的PCB105，PCB118，PCB157和PCB169對細(xì)菌的抑制性能的影響，將含有一定量多氯聯(lián)苯的紙片，平貼在已經(jīng)接種被測細(xì)菌的瓊脂培養(yǎng)基上，將平皿置于37℃下培養(yǎng)48小時后觀察結(jié)果。結(jié)果說明了多氯聯(lián)苯對細(xì)菌的生長是有抑制作用的，但是這種抑制作用并不是很明顯。其中80ppb的PCB169對細(xì)菌的抑制作用較其他幾種來說影響比較大。因此，PCBs不能很好的抑制細(xì)菌的生長，而且可以在細(xì)菌中滯留，危害人體的健康。

關(guān)鍵詞: 多氯聯(lián)苯;安全;評估;測定;毒性; 結(jié)構(gòu); 來源;細(xì)菌

Study of PCBs safety eva luation 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