共查询到18条相似文献,搜索用时 546 毫秒
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用已构建的可降解有机磷酸酯等杀虫药剂的转解毒酶基因工程菌,测定了对特异性底物--乙酸萘酯---NA-和--乙酸萘酯---NA-的分解作用,证明该工程菌高效地表达了解毒酶基因.将该工程菌细胞固定化后,通过对--NA和--NA的降解实验,测定了固定化细胞的酶活.用固定化细胞降解有机氯酸酯类的三氯杀虫酯-7504-、拟除虫菊酯类的溴氰菊酯和有机磷酸酯类的毒死蜱,结果表明,固定化细胞对该3类杀虫剂均具有一定的降解效果.用转解毒酶基因工程菌喂有机磷中毒的鸡,表明该转解毒酶基因工程菌对有机磷中毒的鸡,无论是急性中毒还是慢性中毒都有较明显的解毒作用. 相似文献
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敌敌畏农药是一种广泛使用的中等毒性的有机磷农药,采用传统方法测定难以满足现场测定的需要。试验以戊二醛为交联剂制备了一种基于丁酰胆碱脂酶的ISFET(离子敏场效应管)生物传感器,并将其应用于敌敌畏的测定,考察了不同pH值、底物浓度、抑制时间等对传感器响应(电压)值的影响,得到了最佳测定条件。 相似文献
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用不同浓度的喜旱莲子草水浸液处理钉螺24h,观察其灭螺效果,并用聚丙酰胺凝胶电泳技术比较研究了水浸液对钉螺酯酶同工酶的影响,结果表明:钉螺头足部肌肉的酯酶同工酶在低浓度(0.01g/L)时,活性较强,随水浸液处理浓度升高,活性迅速降低;而肝脏的酯酶同工酶在中等浓度(0.1g/L)时,活性最强,高浓度时(1g/L)有些酶带发生分解、消失。钉螺的死亡率则随着处理浓度的提高,急剧增大。喜旱莲子草干粉水浸液对钉螺酯酶同工酶影响明显,是引起钉螺中毒死亡的原因之一。这为喜旱莲子草作为新型植物灭螺剂的开发打下基础。 相似文献
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丁酰胆碱脂酶电势型生物传感器测定敌敌畏农药残留的抑制性研究 总被引:10,自引:0,他引:10
敌敌畏农药是一种广泛使用的中等毒性的有机磷农药,采用传统方法测定难以满足现场测定的需要。试验以戊二醛为交联剂制备了一种基于丁酰胆碱脂酶的ISFET(离子敏场效应管)生物传感器,并将其应用于敌敌畏的测定,考察了不同pH值、底物浓度、抑制时间等对传感器响应(电压)值的影响,得到了最佳测定条件。 相似文献
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北京市市售鸡蛋和鸭蛋中全氟化合物的污染水平研究 总被引:4,自引:1,他引:3
研究了北京市市售蛋类中全氟化合物的污染水平.分别对14个主要蛋类批发市场中59个摊位的鸡蛋和鸭蛋进行了样品采集,采用高效液相色谱-串联质谱法(HPLC-MS/MS)对17种全氟化合物(11种全氟羧酸盐、3种全氟磺酸盐、1种全氟磺酰胺和2种氟化调聚酸)进行了系统性分析.结果表明北京市市售鸡蛋和鸭蛋样品中均存在一定浓度的全氟化合物污染,其中鸡蛋中共检出9种全氟化合物,以全氟壬酸(PFNA)、全氟庚酸(PFHpA)和全氟辛酸(PFOA)为主,平均含量分别为0.105、0.073和0.069 ng·g-1;鸭蛋中共检出10种全氟化合物,以全氟辛烷磺酸(PFOS)和PFOA为主,平均含量分别为0.378ng·g-1和0.296 ng·g-1.鸡蛋和鸭蛋中均未检出全氟戊酸(PFPeA)、全氟十四酸(PFTA)、全氟丁烷磺酸(PFBS)和8:2饱和调聚酸(FOEA).鸭蛋中总PFCs约是鸡蛋的3.4倍.鸡蛋中PFNA和PFHpA之间(r=0.954)以及鸭蛋中全氟十一酸(PFUnDA)和全氟十三酸(PFTrDA)之间(r=0.915)均存在较强的正相关性.对人体健康风险评价结果显示,北京市市售鸡蛋和鸭蛋中PFOS和PFOA污染水平不会对北京市居民产生即时危害. 相似文献
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Lingyun Wang Gangdou Ding Zhiguang Zhou Xun Liu Yixiao Wang Heidi Qunhui Xie Tuan Xu Pu Wang Bin Zhao 《环境科学学报(英文版)》2017,29(1):165-172
The health risk of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like PCBs (dl-PCBs) to human being should be assessed regularly. To evaluate the contamination levels in various food products in the Chinese market and to assess the dietary exposure of the Chinese population, 11 varieties of food groups totaling 634 samples including beef and mutton, chicken and duck, pork, fish and seafood, milk and dairy products were evaluated. The average concentrations of PCDD/Fs in all groups ranged from 0.291 to 8.468 pg/g whole weight (w.w.). The average toxic equivalency concentrations were from 0.012 pg TEQ/g w.w. for cereal to 0.367 pg TEQ/g fat for marine oil. OCDD and 2,3,7,8-TCDF were the dominant congeners in foodstuffs. The dietary estimated mean intake for the Chinese rural and urban populations were 0.656 and 0.514 pg TEQ/kg body weight/day, respectively, however, the cereal group exposure were higher to the estimate daily intake and contributed 81% for rural and 48% for urban population, followed by fish and seafood which contributed 4% and 16% to the estimate daily intake. The estimated dietary intakes were compared with the toxicological reference values and showed that both rural and urban populations were well below those values. 相似文献
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乐果对土壤中酶活性和微生物数量的影响 总被引:6,自引:0,他引:6
农药对土壤微生物及酶活性的影响,已成为不少国家评价农药使用安全性的重要指标,该文就乐果对土壤中酶活性及微生物数量的影响进行了初步研究。结果表明,乐果对土壤中酸性磷酸酶的影响较大,中性磷酸酶受影响小些;脱氢酶的变化趋势虽与酸性磷酸酶相仿,而受影响程度更大些;乐果对土壤微生物数量的变化影响不大。总之,乐果对土壤微生物及酶活性有一定抑制作用,但恢复较快,这有利于乐果在土壤中的降解。 相似文献
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Biotransfer of heavy metals along a soil-plant-insect-chicken food chain:Field study 总被引:6,自引:0,他引:6
The study investigated the accumulation and transfer of Pb,Zn,Cu,and Cd along a soil-plant-insect-chicken food chain at contaminated sites.The study site nearing the Pb/Zn mine had been contaminated by heavy metals severely.Cadmium and Pb concentrations steadily declined with increasing trophic level (p<0.01),but concentrations of Zn and Cu slightly increased from plant to insect larva (p>0.05).The concentrations of heavy metals were the highest in chicken muscle,with lower values in liver and blood.Bioaccumulation of Pb was observed in the chicken livers.The eliminations of Pb,Zn,Cu,and Cd via insect and chicken feces avoid metal bioaccumulation in insect and chicken body.These results suggest that the accumulation of heavy metals in specific animal organ of tissues could not be neglected,although transfer of metals to chicken from plant and insect is limited. 相似文献
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Oral administration of arsenic trioxide(3 and 6 mg/kg body weight/d) for 30 d caused, as compared with vehicle control, dose-dependent significant reductions in body weight, absolute weight, protein, glycogen, as well as, total, dehydro and reduced ascorbic acid contents both in the liver and kidney of arsenic-treated mice. Succinic dehydrogenase(SDH) and phosphorylase only in the liver activities were significantly reduced in a dose-dependent manner. Acid phosphatase activity was significantly decreased in the liver of low dose arsenic-treated animals;however, significant rise in its activity was observed in high dose group. As compared with vehicle control, treatment also caused significant dose-dependent reductions in SDH, alkaline phosphatase and acid phosphatase activities in the kidney of mice. Vitamin E cotreatment as well as, 30 d withdrawal of arsenic trioxide treatment with or without vitamin E caused significant amelioration in arsenic-induced toxicity in mice. Administration of vitamin E during withdrawal of treatment also caused significant amelioration as compared from only withdrawal of the treatment. It is concluded that vitamin E ameliorates arsenic-induced toxicities in the liver and kidney of mice. 相似文献
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应用植物酯酶抑制技术测定蔬菜水果中农药残留量 总被引:31,自引:2,他引:31
应用植物酯酶的抑制技术,测定蔬菜水果中有机磷和氨基甲酸酯类农药残留量的简易薄层—植物酶抑制(TLC-EI)法。该法对多种农药的最小检出量为毫微克(ng)级,最小检出浓度为0.01pm,添加回收率在80%以上。 相似文献