蜂产品中新烟碱类农药检测前处理方法研究进展

样品前处理方法可分为提取、净化、和浓集三个步骤,有效的前处理方法可以富集目标物,提高灵敏度,降低杂质干扰。该文章综述了近几年对于检测蜂产品中新烟碱类农药的前处理方法,并对前处理方法的主要参数进行归纳总结。     

中草药中14种有机磷农药残留量同时测定——微波辅助提取法

建立了14种有机磷农药在中草药金银花Lonicera chrysantha、三七Panaopseu-do-ginsen、枸杞Lycium chinense中的残留分析方法。采用微波辅助提取,C18-硅胶SPE柱净化,毛细管气相色谱测定,优化了微波提取和净化条件,并与传统振荡提取法进行了比较。标准添加回收率为80.5%～102.7%,相对标准偏差为1.2%～8.1%,最低检出浓度为0.004mg/kg(敌敌畏)～0.026mg/kg(丙溴磷),符合残留分析要求。     

非致死浓度农药对智利植绥螨繁殖和定居的影响

用6种农药的非致死浓度(LC_(n-13)),在实验室内处理菜豆叶的结果说明,对智利螨的繁殖有显著的影响。三氯杀螨醇(84ppm)、氧化乐果(1ppm)、速灭杀丁(0.2ppm)、氯氰菊酯(0.1ppm)、溴氰菊酯(0.025ppm)和灭扫利(0.026ppm)使智利螨的产卵量比对照分别减少35.3％,41.2％、20.8％,65.1％、49.4％和74.7％。用上述农药在温室处理菜豆植株的结果说明,当对照植株上的智利螨定居率为96.7％时,上述农药处理植株上的智利螨定居率依次为48.4％、50.0％、25.0％、11.7％,3.3％和6.7％。菊酯类农药对智利螨定居率的影响明显大于氧化乐果和三氯杀螨醇。植株上残留的微量农药不仅能影响智利螨繁殖能力,而且严重影响其定居率,在螨类的综防工作中值得引起重视。     

Effects of agrochemical residues on four spider taxa: Laboratory methods for pesticide tests with web-building spiders

The susceptibility of web-building and hunting spiders from the tropics (Panama), Europe (F.R. of Germany) and the Middle East (Israel) to 30 pesticides (16 insecticides, 4 acaricides, 1 herbicide, 9 fungicides) was determined. Laboratory test methods for juvenile and adult web-building spiders are described.Philodromus sp. (hunting spider), was completely resistant to all substances;Argiope sp. (web-building spider),Linyphia sp. (web-building spider) andChiracanthium sp. (hunting spider) showed medium to high susceptibility. Insecticides affected spiders in a wide range of responses: from no mortality (most compounds of biological origin) and medium mortality (pyrethrin compounds, organophosphorus and carbamate compounds), to high mortality (cyclo compounds). To both groups of spiders (the hunting and web-building), most acaricides were highly toxic, whereas herbicides and fungicides were nontoxic.     

两种增效复配农药对桑螟的防治效果试验

为有效地控制桑螟对桑园的危害,筛选出2个专门用于防治桑螟的复配药剂配方。在残毒期为5 d的短残毒期配方中,80%敌敌畏、50%辛硫磷、增效剂和水的质量比为1∶1∶1∶2 000;残毒期为11 d长残毒期配方中40%的灭多威、50%的辛硫磷、增效剂和水的质量比为1∶1∶1∶2 000。这2种复配农药的实验室及室外桑园小区防治试验的校正防治效果可达94.4%~96.7%,50 hm2桑园中试的校正防治效果达94.3%~96.1%。2种复配农药对红腹灯蛾、桑毛虫、桑尺蠖也有较好的防治效果。     

分散固相萃取—高效液相色谱法测定水果中多菌灵和噻菌灵

分析了现行苯并咪唑类农药残留检测方法中存在的问题,并对分散固相萃取—高效液相色谱法检测苯并咪唑类农药残留方法进行了研究。通过对方法的条件进行优化、改进,获得高效、快捷、经济的前处理方法,成功建立了分散固相萃取—高效液相色谱法。其中使用C18和PSA吸附剂组合将多菌灵的回收率由文献中大于110%降到91.8%～104.7%,噻菌灵的回收率由文献中的17%～44%提高到88%～102%,满足了要求。在苹果、香蕉、桃、柑橘、葡萄、草莓6种水果上进行方法验证,研究结果表明,农药浓度在0.01～3.0mg/kg内呈良好的线性关系,线性相关系数在0.999以上,平均回收率在88%～104.7%,方法的RSD值小于5%。方法的准确度和精密度都满足要求,为相关标准的制定提供了依据。     

纳米助剂对防治西花蓟马五种植物源农药的增效作用

为有效控制有机基地芹菜上的西花蓟马,本研究在防治西花蓟马的植物源农药中加入一定比例的纳米助剂,以期达到提高植物源农药增效减量的目的。研究结果表明：在五种供试的植物源农药（5%扑利旺、0.3%印楝素、1.5%除虫菊素、0.6%苦参碱、2.5%鱼藤酮）中,0.6%苦参碱是防治西花蓟马的理想药剂,施药后3 d和7 d防治效果为75.58%和66.83%;与纳米助剂按照1：1混合施药后,五种植物源农药的防效均提高10%～20%。0.6%苦参碱增效最为显著,施药后3和7 d防治效果为85.71%和78.05%;若将防治效果达到75%为限值,添加纳米助剂后,0.6%苦参碱的持效期由3 d延长到10 d,延长了农药的喷施间隔期,减少了使用量。     

以沼渣为原料固态发酵生产Bt生物农药

沼渣是沼气工程中产生的副产物,由于其富含营养物质及微量元素,而广泛应用于农业,畜牧业,养殖业等方面。Bt生物农药是一类具有选择性和高效性的杀虫剂,但是由于其原料的成本较高从而限制了生物农药的发展,而沼渣中富含微生物所需要的各种养分并且价格低廉,因此该文以生产沼气后的沼渣为资源,运用固态发酵,探索了利用沼渣制备苏云金杆菌生物农药的可行性。首先对沼渣营养成分进行了分析,分析表明其营养物质丰富,适合苏云金芽孢杆菌的生长与增殖。其次对菌种的沼渣培养基进行了优化,优化后的培养基质量分数为：50%的沼渣添加35%啤酒糟,10%玉米粉,5%豆饼粉,并与常规培养基和单纯沼渣的发酵进程进行了对比。在优化培养基条件下,发酵48 h后,芽孢数达到5.23×1010 CFU/g,毒力效价为16 100 IU/mg。在传统培养基中芽孢数2.55×1010 CFU/g,毒力效价12 500 IU/mg,而在单纯沼渣中Bt产量及毒性为1.74×108 CFU/g,6000 IU/mg。采用沼渣发酵制备Bt生物农药与传统培养基比较,降低了36.3%的生产成本,且发酵性能优良,也为沼渣的利用寻找到崭新的途径。     

作物从土壤中吸收、传递和累积农药的研究进展

农药是保障粮食安全的重要农业投入品,施用后部分农药会沉积在土壤中,甚至会被作物根部吸收,进入作物体内并累积于可食部位,从而导致潜在农产品质量安全问题。研究表明,土壤中的有机质含量、农药的辛醇-水分配系数和作物脂质含量是影响作物吸收非离子型农药的关键因素,作物各部位的脂质含量是影响该类农药累积的关键因素,借助蒸腾作用向上传递是作物根部吸收传导农药的主要动力。本文重点综述了农药被作物的根部吸收、传递和累积及其主要影响因素,结合植物吸收模型的发展及运用,展望了该领域未来发展方向,为农药归趋及应用风险研究提供参考。     

Surveys to assess the amount of pesticide in wool and the use of pesticides by woolgrowers in Queensland.

OBJECTIVE: To measure the amounts of pesticide residue in wool grown in Queensland between 1997 and 1999, and to describe the use of pesticides for the control of lice infestations and blowfly strike in Queensland sheep flocks. DESIGN: Pesticide residues were measured in a random sample of wool from Queensland clips offered for sale during 1998 and 1999. Information on pesticide use was obtained from a trace-back postal survey. PROCEDURE: Samples taken from wool lots were tested for the presence and amount of organophosphorus (OP), synthetic pyrethroid (SP) and insect growth regulator pesticides. A questionnaire seeking information on flock characteristics and pesticide use was sent to the manager of each flock from which a wool sample was tested. RESULTS: The mean amount of OP and SP residue was 2.0 and 0.8 mg/kg, respectively. Ninety-five and 98% of wool samples contained < 9 mg/kg and 7 mg/kg of OP and SP residues, respectively. The mean amount of cyromazine, diflubenzuron and triflumuron was 12.7, 5.8 and 13.0 mg/kg, respectively. The amounts of OP, cyromazine and triflumuron residues were greater in wool from flocks located in southern Queensland. CONCLUSION: Most (95%; 95% CI, 92-97%) Queensland wool clips grown between 1997 and 1999 meet the suggested Australian maximum acceptable residue amounts for OP and SP pesticides.