无公害的植物杀虫剂

植物杀虫剂是指用于防治害虫的植物体的提取物的化学改良性物质。它可以是植物体的全部或一部分,也可以是其中含有的某种有效成分。已知有相当一部分植物如烟草,除虫菊,鱼藤等早已被大量作为杀虫剂使用。植物杀虫剂的特点是不产生公害,它的有效成分     

25年前——发生在博帕尔的悲剧

25年前的12月3日,过程工业历史上最悲惨的悲剧之一在印度博帕尔的一家杀虫剂生产厂里发生了：这天午夜过后不久,甲基异氰酸酯（MIC）——一种剧毒气体,就从这家工厂里大量泄漏出来,人们也许永远不会得知死难者的确切数字,但据估计,应在2000～4000之间,受伤人数在100000人左右或更多。据调查博帕尔事故的国际医学委员会估计,截至1994年,仍有50000多人部分或完全丧失能力。     

水中BPMC等残留农药的分析方法研究

BPMC、Propyzamide、TPN、Diazinon、IBP、MEP、Benthiocarb、Isoxathion、EPN等农药是目前广泛使用的除草剂和杀虫剂,其中部分农药如BPMC被列为毒害品,然而目前还没有可行有效的、针对以上物质的统一检测方法。选用了合适的有机溶剂对多种组分进行同时萃取,经过净化后采用气相色谱-质谱法测定,分析效果较好。     

Enantioselective separation and zebrafish embryo toxicity of insecticide beta-cypermethrin

Enantioselectivity of chiral pollutants is receiving growing concern due to the difference in toxicology and environment fate between enantiomers.In this study,enantiomers of insecticide beta-cypermethrin (beta-CP) were separated on selected chiral column by HPLC,and the toxicity of enantiomers was evaluated using the zebrafish embryo-larval assays.The enantiomers of beta-CP were baseline separated on Chiralcel OD and Chiralpak AD columns and detected by circular dichroism (CD) at 236 nm.Better separation could be achieved at lower temperature (e.g.,20°C) and with lower levels of polar modifiers.Pure enantiomers were obtained on Chiralcel OD.The CD spectra of enantiomers were recorded.By comparing the elution order with a previous similar study,the absolute configuration of beta-CP enantiomers was determined.The individual enantiomers were used in zebrafish embryo test,and the results showed that beta-CP enantioselectively induced yolk sac edema,pericardial edema and crooked body.The 1R-cis-αS and 1R-trans-αS enantiomers showed strong developmental toxicities at concentration of 0.1 mg/L,while the 1S-cis-αR and 1S-trans-αR induced no malformations at higher concentration (e.g.,0.3 mg/L).The results suggest that the enantioselective toxicological effects of beta-CP should be considered when evaluating its ecotoxicological effects.     

9种杀虫剂对中华大刀螂幼虫的毒性

螳螂是田间控制害虫种群增加的重要捕食性天敌之一。以中华大刀螂3龄幼虫(Paratenodera sinensis Saussure)为受试生物,利用9种常用杀虫剂配制成不同浓度梯度的药剂,通过喷雾法直接暴露,分别测定了LC50和死亡率来评价不同杀虫剂对中华大刀螂毒性和危害程度的影响。结果显示,9种杀虫剂对中华大刀螂幼虫的毒性(LC50值)差异很大,用药后24h的LC50在0.7182～347.7962mg·L-1之间,LC95在8.8057～1734.5650mg·L-1之间;用药后48h的LC50在0.3564～193.6887mg·L-1之间,LC95在3.8958～1548.3258mg·L-1之间;用药后72h的LC50在0.2232～115.3391mg·L-1之间,LC95在1.7730～530.6462mg·L-1之间。不同杀虫剂对中华大刀螂幼虫的毒性差异最高达到543.46倍。毒性大小依次为,高效氯氟氰菊酯﹥啶虫脒﹥联苯菊酯﹥毒死蜱﹥噻虫嗪﹥茚虫威﹥吡虫啉﹥阿维菌素﹥苏云金杆菌原粉(Bt)。根据田间推荐浓度处理的死亡率判断,毒死蜱、联苯菊酯、啶虫脒、高效氯氟氰菊酯为有害水平,Bt为中度有害水平,吡虫啉、茚虫威、噻虫嗪为微害水平,阿维菌素接近无害水平。根据LC50与田间推荐浓度的比值判断,阿维菌素、吡虫啉对螳螂种群数量不会产生太大影响;Bt、茚虫威和噻虫嗪对螳螂种群数量会产生一定危害;而毒死蜱、啶虫脒、联苯菊酯和高效氯氟氰菊酯将严重影响螳螂种群数量的稳定性。在24～72h范围内,不同杀虫剂LC50和LC95随施药时间的延长而降低,说明暴露时间越长毒性越大,危害程度也越大。建议在中华大刀螂生活范围内减少高效氯氟氰菊酯、联苯菊酯、啶虫脒和毒死蜱的施用,推荐杀虫剂田间使用量时,除考虑对防治对象的防效,还应考虑对天敌种群的危害,提高药剂使用安全性,保护天敌种群的稳定性。     

几招清除蔬菜上的残余农药

<正>食品安全越来越受人们关注,如何去除农药残留成为大家越来越关心的话题,现在为大家简单介绍几种去除农药残留的方法。加热法随着温度升高,氨基甲酸酯类杀虫剂分解加快。所以对一些其他办法难以处置的蔬菜瓜果可经过加热去除局部农药。常用于芹菜、菠菜、小白菜、圆白菜、青椒、菜花、豆角等。办法是先用清水将外表污物洗净,放入沸水中2~5分钟捞出,然后用清水冲洗1~2遍。     

新烟碱类杀虫剂对蜜蜂的急性毒性及风险评价

为新烟碱类杀虫剂合理使用提供科学依据,本研究采用饲喂法和点滴法测定了9种新烟碱类杀虫剂对蜜蜂的急性毒性效应,且根据风险商值法进行了风险评价,氟啶虫酰胺和吡蚜酮作为对照药剂。试验结果表明:6种新烟碱类杀虫剂(噻虫胺、呋虫胺、吡虫啉、烯啶虫胺、氟啶虫胺腈和噻虫嗪)对蜜蜂经口和接触毒性的48 h-LD50值为1.73×10-3(1.37×10-3~2.45×10-3)~35.3×10-2(30.5×10-2~41.4×10-2)μg·蜂-1,均属于高毒级;其次为氯噻啉,该药剂对蜜蜂经口和接触毒性的48 h-LD50值为56.4×10-2(40.9×10-2~95.5×10-2)和2.05(1.13~3.18)μg·蜂-1,分别为高毒和中毒;而啶虫脒和噻虫啉对蜜蜂经口和接触毒性的48 hLD50值为2.57(1.94~3.75)~9.85(8.23~11.6)μg·蜂-1,为中毒级。对照药剂氟啶虫酰胺和吡蚜酮对蜜蜂经口和接触毒性的48h-LD50值均100μg·蜂-1,为低毒级。风险评价结果表明:噻虫胺、呋虫胺、吡虫啉、噻虫嗪、氯噻啉、烯啶虫胺和氟啶虫胺腈对蜜蜂具有不可接受的风险,啶虫脒、噻虫啉和对照药剂氟啶虫酰胺、吡蚜酮对蜜蜂的风险可接受。因此,在害虫综合治理中,应谨慎使用新烟碱类杀虫剂,以免对蜜蜂产生严重的毒副作用。     

油桐尺蠖病毒杀虫剂的药效分析

油桐尺蠖核型多角体病毒（BsSNPV）是一种高致病力的病毒株,生物测定nPIB（LC50）=1．657×104mL．经过全国7个省20多个单位联合试验,生物统计结果表明：BsSNPV防治第1代油桐尺蠖虫口下降率为97．2％;防治第2代油桐尺蠖虫口下降宰为93．97％;F测验其t值为0．184,小于理论t0．05（29）＝2．045．优于敌百虫、DDVP、辛硫磷和BT等农药是一种杀虫效果稳定、使用安全、经济有效的生物杀虫剂．     

Biodegradation of methyl parathion by Acinetobacter radioresistens USTB-04

Biodegradation of methyl parathion (MP),a widely used organophosphorus pesticide,was investigated using a newly isolated bacterium strain Acinetobacter radioresistens USTB-04.MP at an initial concentration of 1200 mg/L could be totally biodegraded by A.radioresistens USTB-04 as the sole carbon source less than 4 d in the presence of phosphate and urea as phosphorus and nitrogen sources,respectively.Biodegradation of MP was also achieved using cell-free extract of A.radioresistens USTB-04.MP at an initial concentration of 130 mg/L was completely biodegraded in 2 h in the presence of cell-free extract with a protein concentration of 148.0 mg/L,which was increased with the increase of pH from 5.0 to 8.0.Contrary to published reports,no intermediate or final degradation metabolites of MP could be observed.Thus we suggest that the cleavage of C--C bond on the benzene ring other than P-O bond may be the biodegradation pathway of MP by A.radioresistens USTB-04.     

Effect of copper on the degradation of pesticides cypermethrin and cyhalothrin

The influence of coexisting copper (Cu) ion on the degradation of pesticides pyrethroid cypermethrin and cyhalothrin in soil and photodegradation in water system were studied.Serial concentrations of the pesticides with the addition of copper ion were spiked in the soil and incubated for a regular period of time,the analysis of the extracts from the soil was carried out using gas chromatography (GC).The photodegradation of pyrethroids in water system was conducted under UV irradiation.The effect of Cu~(2 ) on the pesticides degradation was measured with half life (t_(0.5)) of degradation.It was found that a negative correlation between the degradation of the pyrethroid pesticides in soil and Cu addition was observed.But Cu~(2 ) could accelerate photodegradation of the pyrethroids in water.The t_(0.5) for cyhalothrin extended from 6.7 to 6.8 d while for cypermethrin extended from 8.1 to 10.9 d with the presence of copper ion in soil.As for photodegradation,t_(0.5) for cyhalothrin reduced from 173.3 to 115.5 rain and for cypermethrin from 115.5 to 99.0 min.The results suggested that copper influenced the degradation of the pesticides in soil by affecting the activity of microorganisms.However, it had catalyst tendency for photodegradation in water system.The difference for the degradation efficiency of pyrethroid isomers in soil was also observed.Copper could obviously accelerate the degradation of some special isomers.