油菜素内酯降低油菜毒死蜱残留的最佳浓度研究

以书香小油菜的毒死蜱残留量为调查对象,研究不同浓度的油菜素内酯降低油菜毒死蜱残留的作用,并采用气相色谱方法检测油菜中毒死蜱的含量。结果表明,油菜素内酯降低毒死蜱残留的最佳浓度是将其稀释1 000倍。     

Chronic chlorpyrifos-induced oxidative changes in the testes and pituitary gland of Wistar rats: Ameliorative effects of vitamin C

Chlorpyrifos (CPF), a chlorinated organophosphate insecticide that is widely used in agriculture and public health, has been implicated in male reproductive toxicity. Apart from acetylcholinesterase inhibition, CPF has been shown to induce changes characteristic of oxidative stress. Therefore, the aim of the present study was to evaluate the effects of vitamin C on oxidative changes in the testes and pituitary gland of rats chronically exposed to CPF. Twenty adult male Wistar rats were divided into four groups of five animals each: Group I (S/oil) received soya oil (2 ml/kg); Group II (VC) was administered with vitamin C (100 mg/kg); Group III (CPF) was given CPF (10.6 mg/kg; ∼1/8th LD₅₀); Group IV (VC + CPF) was pretreated with vitamin C (100 mg/kg) and then given CPF (10.6 mg/kg), 30 min later. The regimens were administered orally by gavage once daily for 15 weeks. Thereafter, the rats were sacrificed and the testes and pituitary glands were evaluated for the concentration of malonaldehyde (MDA) and activities of superoxide dismutase (SOD) and catalase (CAT). The result shows that CPF increased MDA concentration and reduced activities of SOD and CAT, which were ameliorated by pretreatment with vitamin C.     

Oxidative stress response and histopathological changes due to atrazine and chlorpyrifos exposure in common carp

Atrazine (ATR) and chlorpyrifos (CPF) are the most common pesticides found in freshwater ecosystems throughout the world. Herein, we investigated the oxidative stress responses and histopathological changes in the liver and gill of common carp after a 40-d exposure to CPF and ATR, alone or in combination, and a 20-d recovery treatment. We found that exposure to ATR, CPF or their mixture for 40 d could induce decrease in antioxidant enzyme (SOD, CAT and GSH-Px) activities and increase in MDA content in a dose-dependent manner in the liver and gill of common carp. Especially with regard to the pathological changes, the tissue damage increased in severity in a dose-dependent manner. The liver tissue of common carp revealed different degree of hydropic degeneration, vacuolisation, pyknotic nuclei, and fatty infiltration. The gills of common carp displayed varied degrees of epithelial hypertrophy, telangiectasis, oedema with epithelial separation from basement membranes, general necrosis, and epithelial desquamation. After a 20-d recovery treatment, the antioxidant enzyme activities and MDA content were significantly lower (p < 0.05) than in the corresponding exposure groups in all of the highest doses, but not in the lower doses. To our knowledge, this is the first report of subchronic oxidative stress and histopathological effects caused by ATR, CPF and their mixture in the common carp. Thus, the information presented in this study is helpful to understand the mechanism of ATR-, CPF- and ATR/CPF-mixture-induced oxidative stress in fish.     

Lipid peroxidation and oxidative stress in rat erythrocytes induced by chlorpyrifos and the protective effect of zinc

Male and female rats were orally administered chlorpyrifos at a dose of 6.75 mg kg⁻¹ body weight for 28 consecutive days. An additional chlorpyrifos group received zinc (227 mg l⁻¹) in drinking water throughout the experimental duration. Two groups more served as controls; one received water only and the other received zinc in drinking water. Administration of chlorpyrifos resulted in a significant increase in lipid peroxidation (LPO) level and significant decrease in the activities of superoxide dismutase (SOD), glutathione-s-transferase (GST), catalase (CAT) and acetylcholinesterase (AChE) in erythrocytes of male and female rats. In contrast, zinc-chlorpyrifos treatment showed insignificant differences (p ? 0.05-0.01), compared to control results, regarding LPO, SOD, GST and CAT. In case of AChE, supplementation of zinc showed little alteration in the activity of this enzyme in the rats treated with chlorpyrifos. It can deduce that chlorpyrifos induced oxidative stress and lipid peroxidation in erythrocytes of male and female rats. The overall results reveal the pronounced ameliorating effect of zinc in chlorpyrifos-intoxicated rats and variation in the response of male and female animals regarding alteration in the level of some biochemical parameters and LPO.     

蔬菜中残留毒死蜱的检测方法

通过对5种蔬菜中添加毒死蜱标样的回收率试验,研究蔬菜毒死蜱监测方法中震荡提取时间、淋洗液配比、层析硅胶用量、淋洗液选择时间等关键步骤的最佳定量组合。结果表明提取时间为30min,淋洗液用单一的丙酮,层析柱中填充1g硅胶,淋洗过程中取6min以后的过柱淋洗液做色谱分析,既可大量清除蔬菜中含有的对色谱峰的干扰因素,同时也保证回收率达到90%～120%之间,得到较好的效果。     

白蚁防治药剂在模拟房屋白蚁预防施工土壤中残留降解性动态研究

[目的]研究房屋白蚁预防药剂毒死蜱和联苯菊酯在合肥地区土壤中的降解动态。[方法]以毒死蜱和联苯菊酯为供试药剂,研究白蚁预防药剂在土壤中的残留降解性.[结果]添加浓度为50mg／kg时,毒死蜱和联苯菊酯的回收率分别为96．90％和93．25％,变异系数分剐为2．76％和4．02％、毒死蜱在土壤中的降解可以分为先快后慢2个阶段,而联苯菊酯在土壤中的降解符合一级动力学方程,、2种药剂的降解速度都较快,但联苯菊酯的降解速度比毒死蜱慢,毒死蜱的半衰期为79．68d,联苯菊酯的半衰期为94．96d。由2种药剂的降解方程计算得联苯菊酯的有效期为911d,毒死蜱的有效期为478d。[结论]该研究为白蚁防治药剂在房屋白蚁预防工程中的合理应用、安全性评价以及制定行业质量标准提供了理论依据。     

毒死蜱在大白菜上的消解动态研究

采用气相色谱法测定不同施药浓度毒死蜱在大白菜中的消解规律。结果表明:毒死蜱在白菜中的半衰期为3.2~3.6 d,在正常喷施浓度下,施药后15天毒死蜱在大白菜中的残留量仍超过我国最高限量标准0.1 mg/kg。用40%毒死蜱乳油防治大白菜害虫,由于地理位置、栽培方式、气候条件、施药浓度、施药次数的不同,安全间隔期差别也较大。     

基于活的但非可培养细菌降解毒死蜱的研究

[目的]探索降解毒死蜱的新的微生物资源.[方法]应用最大或然数（MPN）法,通过添加适量复苏促进因子（Rpf）从多种土壤及污水生物处理系统中分离活的非可培养（VBNC）资源菌种,根据文献报道的已知毒死蜱降解菌株的系统关系综合分析,初步筛选出与已知降解毒死蜱菌种近缘的VBNC菌株并进行降解试验.[结果]共筛选出6株具有毒死蜱降解能力的菌株,其中菌株CHZYR63对毒死蜱的生物降解能力最强,经Box-behnken响应面法优化后降解率可达70.15％.[结论]可培养化VBNC菌种资源在残留农药降解方面有较大的利用价值,为揭示受染环境中VBNC微生物的形成及其活性化、环境污染物质的共代谢等微生物群体的相互作用机制提供了参考.     

40%毒死蜱乳油在番茄果实中的残留降解动态研究

利用高效气相色谱法研究了40%毒死蜱乳油在番茄果实中的残留降解动态。结果表明,在推荐剂量75 mL/hm2下,其降解半衰期为2.49 d;在加倍剂量150 mL/hm2下,降解半衰期为2.55 d,药后7 d的残留量为0.200 0 mg/kg,符合我国对毒死蜱在番茄上残留≤0.5 mg/kg的要求。     

白蚁防治剂毒死蜱和氰戊菊酯在土壤中的吸附行为

应用平衡法研究了毒死蜱和氰戊菊酯在取样于宁波地区的3种典型土壤（淡涂泥土、黄斑青紫泥土和山地黄泥砂土）的吸附行为。结果表明,淡涂泥土、黄斑青紫泥土和山地黄泥砂土对毒死蜱的吸附常数分别为121.4088、477.7604、3537.0809;对氰戊菊酯的吸附常数分别为15.7476、100.8772、102.3091,表明无论是山地黄泥砂土、黄斑青紫泥土,还是淡涂泥土,对毒死蜱的吸附性均远高于氰戊菊酯。通过吸附常数Kd与土壤的有机质含量、pH值以及阳离子代换量等理化性质进行单因子回归分析,表明毒死蜱和氰戊菊酯的土壤吸附率（Y）除与土壤有机质含量呈显著正相关外,与土壤阳离子交换量的相关性也呈显著相关性