溴氰菊酯农药在粮食中残留量分析方法的探讨

本文采用毛细管气相色谱法,对测定粮食中溴氰菊酯农药残留量的多种提取、净化、检测条件进行了比对,样品粉碎后经石油醚(30℃～60℃)提取、柱色谱净化,选择用石油醚加乙酸乙酯(95 5,体积分数)作为洗脱溶剂,净化液收集浓缩后,采用毛细管柱柱DB1(30 m×0.25 mm×0.25μm)和电子捕获检测器(ECD)分析检测溴氰菊酯的残留量.     

溴氰菊酯在罗非鱼组织中的累积及对谷胱甘肽-S-转移酶的影响

以罗非鱼Tilipia为试验鱼类,研究了其暴露于不同浓度溴氰菊酯后其组织中溴氰菊酯的含量和谷胱甘肽-S-转移酶GST活性的动态变化。结果表明,罗非鱼肌肉和肝脏组织中的GST的正常值分别为(4.39±0.2)U.mg.prot-1和(13.3±0.3)U.mg.prot-1。采用不同浓度的溴氰菊酯处理罗非鱼25 d,除了1.0μg.L-1浓度组罗非鱼体内无明显累积,GST与对照组相比无显著差异外,其余各浓度组均有一定的累积,同时GST发生了明显的变化。GST的变化规律为先升高后降低,即溴氰菊酯对罗非鱼体内的GST是先诱导后抑制,且这种变化幅度肝脏比肌肉大。2.0￣10.0μg.L-1浓度组经15￣20 d可在肌肉和肝脏中达到累积-释放的动态平衡,最大累积系数分别为1.85和2.20。溴氰菊酯在罗非鱼组织中达到累积平衡时,其累积量与GST活性呈较明显的负相关。研究表明,1.0μg.L-1以下的溴氰菊酯对罗非鱼没有生化毒性影响,罗非鱼组织中的溴氰菊酯累积量和GST可用来评价农药对鱼类的毒性效应。     

固相萃取-高效薄层色谱测定茶叶中甲氰菊酯和溴氰菊酯残留

本文建立了简便快速测定茶叶中甲氰菊酯和溴氰菊酯残留的固相萃取-高效薄层色谱分析方法。以乙腈为提取剂, 活性炭固相萃取柱和中性氧化铝固相萃取柱串联净化,高效薄层色谱检测。 结果表明,在给定色谱条件下甲氰菊酯（Rf= 0.49 ）和溴氰菊酯（Rf=0.64）的最小检测限分别为20.0ng和10.0ng。 茶叶中甲氰菊酯和溴氰菊酯的添加回收率为94.8-108% 和90.5-102%（添加浓度0.50-10.0 mg/kg）,相对标准偏差为1.71-6.22% 和3.82-6.39%。 本文所建立方法的准确性、精确性均满足农药残留分析的要求。     

溴氰菊酯对加州腔蚓的急性中毒效应

于不同时间地点观察加州腔蚓在溴氰菊酯浓度为40mg／kg、20mg／kg、10mg／kg、5mg／kg、2．5mg／kg土壤中的急性中毒症状、异常行为及死亡状况,结果发现：与低浓度相比,高浓度（≥20mg／kg）下蚯蚓环带红肿、粘液分泌、身体翻滚等症状出现的时间较短,不足7min,在浓度为2．5mg／kg时上述症状出现的时间最长,约为60min;蚯蚓中毒翻滚持续时间,在40mg／kg浓度下最短,为233．1min,在2．5-10mg／kg浓下时持续最长,约600min;蚯蚓中毒致死时间,在40mg／kg和5mg／妇浓度下达极值,分别为317．9min和2140min,前者死亡时体重下降9．48％,后者死亡时体重下降近30％。统计分析表明：溴氰菊酯对加州腔蚓的急性毒性效应与中毒时间和农药剂量存在相关性。     

Genetics and evidence for an esterase-associated mechanism of resistance to indoxacarb in a field population of diamondback moth (Lepidoptera: Plutellidae)

Bioassays (at generation G2) with a newly collected field population (designated CH3) of Plutella xylostella L. from farmers' fields in the Cameron Highlands, Malaysia, indicated resistance ratios of 813-, 79-, 171-, 498- and 1285-fold for indoxacarb, fipronil, spinosad, deltamethrin and Bacillus thuringiensis toxin Cry1Ac respectively compared with a laboratory susceptible population (Lab-UK). At G2 the field-derived population was divided into two subpopulations: one was selected (G2 to G7) with indoxacarb (indoxa-SEL), while the second was left unselected (UNSEL). A significant reduction in the resistance ratio for each compound was observed in UNSEL at G8. For indoxa-SEL, bioassays at G8 found that selection with indoxacarb gave a resistance ratio of 2594 compared with Lab-UK and of 90 compared with UNSEL. The toxicity of fipronil, spinosad and deltamethrin was not significantly different in indoxa-SEL at G8 compared with G2 but was significantly greater than UNSEL at G8. The toxicity of Cry1Ac was significantly reduced in indoxa-SEL at G8 compared with G2 but was also significantly greater than UNSEL at G8. This suggests that indoxacarb selection maintained resistance to these compounds in the indoxa-SEL population. Synergist studies indicated that resistance to indoxacarb in indoxa-SEL was esterase associated. Logit regression analysis of F1 reciprocal crosses between indoxa-SEL and Lab-UK indicated that resistance to indoxacarb was inherited as an autosomal, incompletely recessive (D(LC) = 0.35) trait. Tests of monogenic inheritance suggested that resistance to indoxacarb was controlled by a single locus.     

Neurotoxic implications of the agonistic action of CS-syndrome pyrethroids on the N-type Ca(v)2.2 calcium channel

BACKGROUND: Cismethrin (T-syndrome) and deltamethrin (CS-syndrome) pyrethroids have been previously shown to increase membrane depolarization and calcium influx, but only deltamethrin increased Ca(2+)-dependent neurotransmitter release from rat brain synaptosomes. Deltamethrin's action was blocked by omega-conotoxin GVIA, delineating a separate action at N-type Ca(v)2.2 channels that is consistent with the in vivo release of neurotransmitter. It is hypothesized that other CS-syndrome pyrethroids will elicit similar actions at presynaptic nerve terminals.RESULTS: Nine additional pyrethroids were similarly examined, and these data were used in a cluster analysis. CS-syndrome pyrethroids that possessed alpha-cyano groups, cypermethrin, deltamethrin and esfenvalerate, all caused Ca(2+) influx and neurotransmitter release and clustered with two other alpha-cyano pyrethroids, cyfluthrin and cyhalothrin, that shared these same actions. T-syndrome pyrethroids, bioallethrin, cismethrin and fenpropathrin, did not share these actions and clustered with two non-alpha-cyano pyrethroids, tefluthin and bifenthrin, which likewise did not elicit these actions. Deltamethrin reduced peak current of heterologously expressed wild-type Ca(v)2.2, increased peak current of T422E Ca(v)2.2 and was 20-fold more potent on T422E Ca(v)2.2 than on wild-type channels, indicating that the permanently phosphorylated form of Ca(v)2.2 is the preferred target.CONCLUSIONS: Ca(v)2.2 is directly modified by deltamethrin, but the resulting perturbation is dependent upon its phosphorylation state. The present findings may provide a partial explanation for the different toxic syndromes produced by these structurally distinct pyrethroids.     

三角帆蚌稚蚌培育阶段摇蚊幼虫的药物杀灭试验

为杀灭三角帆蚌(Hyriopsis cumingii)稚蚌培育池中的摇蚊幼虫,以吡喹酮、伊维菌素、阿维菌素、氰戊菊酯等8种常用水产杀虫药,进行稚蚌培育池中摇蚊幼虫杀灭效果试验,再对筛选出的药物进行急性毒性试验,并据此进行稚蚌培育池中杀灭摇蚊幼虫的药物应用试验.结果显示:溴氰菊酯是稚蚌培育池杀灭摇蚊幼虫的理想药物;在平均...     

Deltamethrin resistance in the sea louse Caligus rogercresseyi (Boxhall and Bravo) in Chile: bioassay results and usage data for antiparasitic agents with references to Norwegian conditions

The sea louse Caligus rogercresseyi is a major threat to Chilean salmonid farming. Pyrethroids have been used for anticaligus treatments since 2007, but have shown reduced effect, most likely due to resistance development. Pyrethroid resistance is also a known problem in Lepeophtheirus salmonis in the Northern Hemisphere. This study describes the development of deltamethrin resistance in C. rogercresseyi based on bioassays and usage data for pyrethroids in Chilean aquaculture. These results were compared to bioassays from L. salmonis from Norway and to Norwegian usage data. Available deltamethrin bioassay results from 2007 and 2008, as well as bioassays from Norway, were collected and remodelled. Bioassays were performed on field‐collected sea lice in region X in Chile in 2012 and 2013. Bioassays from 2007 were performed prior to the introduction of pyrethroids to the Chilean market. Both the results from 2008 and 2012 showed an increased resistance. Increased pyrethroid resistance was also indicated by the increased use of pyrethroids in Chilean aquaculture compared with the production of salmonids. A similar trend was seen in the Norwegian usage data. The bioassay results from Chile from 2012 and 2013 also indicated a difference in the susceptibility to deltamethrin between male and female caligus.     

溴氰菊酯人工抗原的合成及偶联比的测定

溴氰菊酯农药分子的人工抗原合成是酶联免疫分析技术的关键,利用重氮化法将合成的溴氰菊酯半抗原(±)α-氰基对氨基苯氧基苄基(1R,3R)-2,2-二甲基-3-(2,2-二溴乙烯基)环丙烷羧酸酯分别偶联到牛血清白蛋白(BSA)和鸡卵清白蛋白(OVA)上制得两种人工抗原。合成的两种溴氰菊酯人工抗原用于动物免疫及免疫后抗体的检测,测得它们的偶联比分别为6∶1和7∶1。     

棉铃虫对溴氰菊酯、三氟氯氰菊酯及其复配剂的抗性趋势与交互抗性

在70％的高选择压下,分别用溴氰菊酯、三氟氯氰菊酯和凯明2号(50％辛硫磷·甲基对硫磷·三氟氯氰乳油,即含三氟氯氰菊酯的复配药剂)对室内饲养了12代未经农药处理的棉铃虫Helicoverpa armigera(H(?)bner)敏感品系进行了抗性筛选。结果,经连续筛选至第12代的LD_(50)值与筛选前第1代的LD_(50)值比较,抗溴氰菊酯种群对溴氰菊酯的抗性为136.7倍,属高抗水平;抗三氟氯氰菊酯种群对三氟氯氰菊酯的抗性为9.5倍,抗凯明2号种群对凯明2号的抗性为3.4倍,均属低抗水平。用8种常用杀虫剂分别对这3个种群在停止上述杀虫剂筛选2代后进行了交互抗性分析。结果表明,3个种群平均对8种杀虫剂的抗性倍数中,对溴氰菊酯、氰戊菊酯、灭多威的抗性极显著高于其余5种杀虫剂;3个种群的平均抗性倍数之间差异极显著,顺序依次为抗溴氰菊酯种群>抗三氟氯氰菊酯种群>抗凯明2号种群;以平均抗性倍数表示的抗性种群与杀虫剂的交互作用有以下几个结果:①高抗溴氰菊酯的种群对氰戊菊酯和灭多威有极显著的交互抗性,但对三氟氯氰菊酯和凯明2号仍反应敏感。②抗三氟氯氰菊酯和抗凯明2号的2个种群对溴氰菊酯有极显著的交互抗性;抗三氟氯氰菊酯种群对灭多威和氰戊菊酯有一定抗性,抗凯明2号种群对硫丹有一定抗性。