溴氰菊酯在团头鲂体内的富集消除规律研究

【目的】对溴氰菊酯(DM)在团头鲂体内的富集及消除规律进行研究,为水环境中污染物残留及水产品的质量安全问题研究提供理论依据。【方法】在(18±0.5)℃水温下,以团头鲂为研究对象,经5μg/L DM药浴后,利用气相色谱法分析不同时间DM在血浆、肝脏、肌肉、皮肤、鳃、胆组织中的药物残留,采用3p97药代动力学软件对DM在血浆中的血药浓度时间数据进行拟合,构建DM在各组织中的消除曲线方程。【结果】DM在血浆中的峰值浓度(Cmax)为75.96μg/L,达峰时间(Tmax)为7.05h,药-时曲线下面积AUC为1 524.69(μg·h)/L,吸收半衰期(T1/2(ka))为3.66h,消除半衰期(T1/2(ke))为6.73h;DM在团头鲂各组织中富集的浓度从高到低依次为鳃血浆肝脏皮肤肌肉胆;肝脏、肌肉、皮肤、鳃及胆组织对DM的消除半衰期(T1/2)分别为13.75,12.55,12.55,5.35和3.28d。团头鲂血浆、肝脏及鳃组织中的DM含量于药浴12h后明显降低,各组织中的DM含量84h后均降至(14.37±11.65)μg/kg以下,低于我国规定的DM在鱼肌肉中的最高残留限量(30μg/kg);但低含量DM在团头鲂体内维持时间较长,768h(32d)时在皮肤、肝脏、鳃及肌肉组织中仍有残留。【结论】DM在团头鲂体内吸收分布迅速,在鳃、血浆和肝脏组织中富集浓度较高,其消除时间也较长,药浴后768h(32d)在大部分组织中仍能检出。     

Sub-lethal effects of deltamethrin on walking behaviour and response to host kairomone of the egg parasitoid Trissolcus basalis

The lethal doses of the pyrethroid deltamethrin were estimated for the egg parasitoid Trissolcus basalis (Wollaston) (Hymenoptera: Scelionidae), and the sub-lethal effects of an LD25 on female walking behaviour were evaluated. Linear speed of treated parasitoids was reduced compared with that of untreated ones for a period of up to 24 h. The sub-lethal effects of deltamethrin on parasitoid response to patches contaminated by a contact kairomone from its host, Nezara viridula L (Heteroptera: Pentatomidae), was also evaluated. Both treated and untreated parasitoids responded to host-contaminated patches by increasing residence time and decreasing linear speed. However, treated females showed a significantly lower residence time compared with untreated females. Both treated and untreated females showed a similar decrease over time in the proportion of time spent in the host-contaminated patch. Hence, we hypothesise that the sub-lethal effect of deltamethrin on host foraging may decrease T basalis efficacy in controlling N viridula.     

Effects of sea louse chemotherapeutants on early life stages of the spot prawn (Pandalus platyceros)

The effects of five salmon aquaculture anti-sea louse chemotherapeutant active ingredients [azamethiphos (AZ), hydrogen peroxide (HP), emamectin benzoate (EB), cypermethrin (CP) and deltamethrin (DM)] were examined in five life stages (egg, Stage I, Stage III, Stage V and juvenile) of Pacific spot prawn (Pandalus platyceros) for two exposure durations (1-h and 3-h). Endpoints affected by exposures to chemotherapeutants included morbidity in all life stages, egg hatch success, hatchling fitness, latency to moult between successive stages and survival to the juvenile stage. Across life stages, 1-h and 3-h median lethal effect concentrations on morbidity ranged from 73 to 809 mg/L HP; 10–236 µg/L AZ; 321 to >1200 µg/L EB; 0.1 to >5 µg/L CP; and 12 to >1000 ng/L DM. Across endpoints, DM was the most toxic, followed by CP, AZ and EB, followed by HP, which was generally observed to be the least toxic regardless of endpoint examined. The embryo and juvenile life stages were generally more resilient to effects than any larval life stage. Longer duration (3-h) exposures were generally more potent than shorter (1-h) exposures, with up to a threefold greater magnitude of effect when these exposure time frames were compared. Considering predicted environmental concentrations, the estimated greatest risk to ELS spot prawns was observed to be posed by DM, followed by CP, AZ and then EB, with a variable relative risk of HP across different endpoints/life stages.     

气相色谱法快速测定水产品中硫丹和溴氰菊酯残留量

建立了气相色谱法快速检测水产品中硫丹和溴氰菊酯残留量的分析方法.样品用乙腈水提取,正己烷除脂,提取液经液液萃取和反萃取,电子捕获检测器检测,外标法定量.通过优化前处理和上机条件,硫丹的检出限为0.004 mg/kg,溴氰菊酯的检出限为0.01 mg/kg.2种农药在检出限1、2、5倍加标水平下,回收率64.6%～88.9%,相对标准偏差4.1%～9.5%.此方法操作简便快速、重现性好且成本低,可以达到日本肯定列表中对2种农药的检测低限,满足水产品进出口检测要求.     

中华稻蝗田间种群对马拉硫磷和溴氰菊酯的敏感性及其毒理机制的研究

采用生物和生化测定方法,研究了3个中华稻蝗种群对马拉硫磷和溴氰菊酯的敏感性及相关酶系的作用。生物测定结果表明,汉中种群对马拉硫磷和溴氰菊酯的LD50值均最高,临猗种群次之,繁峙种群最低。繁峙和汉中种群对溴氰菊酯比对马拉硫磷敏感,临猗种群则相反。结合生物测定结果和各种群的防治背景,认为杀虫剂的选择压力是引起这3个种群对杀虫剂敏感性差异的主要原因。在无杀虫剂选择压力的作用下,抗性会逐渐消退。生化测定结果表明,汉中种群的酯酶活性最高,繁峙种群次之,临猗种群最低。当以α-NA为底物时,汉中种群酯酶活性分别是临猗和繁峙种群的2.54和1.57倍;当以α-NB为底物时,汉中种群酯酶活性分别是临猗和繁峙种群的1.61和1.53倍;当以β-NA为底物时,汉中种群酯酶活性分别是临猗和繁峙种群的1.84和1.59倍。繁峙种群的谷胱甘肽S-转移酶活性最高,临猗和汉中种群的谷胱甘肽S-转移酶活性相近。此外,繁峙种群的乙酰胆碱酯酶活性最高,临猗种群次之,汉中种群最低。3种氧化型有机磷抑制剂对3个种群乙酰胆碱酯酶体外抑制结果表明,用对氧磷作为抑制剂时,汉中种群的双分子速率常数ki值比临猗和繁峙种群分别降低了7.20和8.50倍;当以氧化毒死蜱作为抑制剂时,汉中种群的ki值比临猗和繁峙种群分别降低了1.21和1.77倍;当以甲基内吸磷为抑制剂时,汉中种群的ki值比临猗和繁峙种群分别降低了7.91和13.43倍。从生物测定和生化测定的结果可以推断,酯酶活性的提高和乙酰胆碱酯酶对抑制剂的敏感性降低是引起3个种群对杀虫剂敏感性差异的主要原因,而谷胱甘肽S-转移酶和乙酰胆碱酯酶活性的变化是次要原因。