酶抑制法快速检测蔬菜中有机磷和氨基甲酸酯类农药残留

概述了酶抑制法快速检测蔬菜中有机磷和氨基甲酸酯类农药残留技术的研究现状、检测原理、应用情况和存在的问题。酶抑制法具有检测时间短、成本低、操作简便等特点,是目前我国农药残留检测的一种有效的初筛方法。     

高效液相色谱柱后衍生化法检测蔬菜中氨基甲酸酯类杀虫剂农药残留

本文建立蔬菜中多种氨基甲酸酯类杀虫剂残留分析方法。样品以丙酮、二氯甲烷混合溶剂提取，以活性炭/Celite545柱净化，以高效液相色谱柱后衍生系统、荧光检测器检测。方法最低检出浓度1-2μg/kg,添加回收率70%-111.1%，相对标准偏差2.02%-12.09%。     

氟虫腈偶联磷酸酯及氨基甲酸酯类化合物的合成及生物活性

依据活性亚结构拼接原理,合成了6个新型含有磷酸酯和氨基甲酸酯结构片段的氟虫腈衍生物,其结构经核磁共振氢谱和碳谱、电喷雾质谱(ESI-MS)以及元素分析确证。初步生物活性及毒性测定结果表明:目标化合物对斜纹夜蛾 Spodoptera litura 和亚洲玉米螟 Ostrinia furnacalis 幼虫均具有良好的杀虫活性,其中化合物 1和2 对亚洲玉米螟幼虫的杀虫活性优于氟虫腈,LC50值分别为0.85和2.01 μ g/mL;目标化合物对意大利蜜蜂 Apis mellifera L.的毒性均显著低于氟虫腈。     

分散固相萃取-反相高效液相色谱法测定蔬菜、水果中10种氨基甲酸酯类农药残留

建立分散固相萃取-反相高效液相色谱同时测定蔬菜和水果中10种氨基甲酸酯类农药(涕灭威,涕灭威砜,涕灭威亚砜,克百威,3-羟基克百威,灭多威,甲萘威,异丙威,速灭威,仲丁威)残留的分析方法。样品经乙腈提取,PSA分散固相萃取净化,液相色谱柱后衍生分离,荧光检测(λex＝330 nm, λem＝465 nm)测定,外标法定量。10种农药在0.005～0.50 mg/L范围内线性关系良好;检出限在0.004～0.008 mg/L;平均加标回收率在75.6%～112.3%,相对标准偏差(RSD)在 0.8%～10.2%。该方法具有快速、灵敏、准确、重现性好以及操作简单等特点,适合日常大批量蔬菜和水果样品中10种氨基甲酸酯类农药残留的测定。     

A novel immobilized cholinesterase for on-site screening of organophosphate and carbamate compounds

Acetylcholinesterase was physically adsorbed on polyvinylpyrrolidone K30 to prepare a novel immobilized cholinesterase, which was described for the first time. The immobilized enzyme was tested for its reactivity, enzyme activity stability, the solubility, the influence of pH and buffer, and characteristic reactivity with inhibitors, e.g., organophosphate and carbamate compounds. The result revealed that the immobilized cholinesterase held its original activity in solution, stable enough, easy to dissolve for convenient operation, and this immobilized cholinesterase could be well used for rapid, on-site screening of organophosphate and carbamate compounds, together with a portable pesticide analyzer.     

The Use of a Daphnia magna Bioassay for Rapid Screening of Acute Intoxications with Insecticides in Dogs and Cats

Sudden death due to acute insecticide intoxications occurs frequently in dogs and cats. The absence of characteristic lesions at autopsy often renders post-mortem diagnosis dependent on the analysis of samples taken from the carcase at autopsy. In the present study, a bioassay utilizing Daphnia magna was proposed and tested as a rapid screening method for acute intoxications in dogs and cats. The bioassay was shown to be highly sensitive for detecting carbamate and organophosphate insecticides in the stomach contents. Generally, the mean survival time of the waterfleas in the control group was 5.17 h (SD = 1.24) and in the intoxicated group 1.32 h (SD = 1.49), during a 6 h observation period. If a cut-off is set at 4 h, this Daphnia bioassay gave 5.5% false negative results and 18.2% false positive results, using the results of toxicological analyses as a gold standard.     

A biochemical mechanism of resistance to pirimicarb in two glasshouse clones of Aphis gossypii

The susceptibility of three clones of Aphis gossypii Glover to 15 insecticides was established by bioassay. A high level of resistance towards pirimicarb was confirmed for a clone from Holland (Dutch R) and a clone from Japan (Jap R), while the susceptible clone (S) was killed by very low doses of the insecticide. However, only limited cross-resistance was shown towards other carbamates and organophosphates, and no marked resistance to the pyrethroids tested. The acetylcholinesterase (AChE) of both resistant clones hydrolysed acetyl-choline faster than that of susceptible aphids, with greatest enzyme activity shown by the Dutch R clone. Inter-clone differences in these rates were consistent with differences in catalytic centre activities. Inhibition (I₅₀) of AChE by pirimicarb was approximately 900-fold higher for the resistant clones than for the S clone. First-order kinetics revealed that resistance to pirimicarb in Dutch R and Jap R involved a modified AChE which had a reduced (approximately 350-fold) affinity (K_d) for pirimicarb. The marked change in AChE affinity for pirimicarb was not repeated with the other carbamates tested, ethiofencarb and aldicarb. It was considered that the resistant aphids would not require mechanisms in addition to insensitive AChE in order to show the high level of resistance to pirimicarb shown in the bioassay.     

基于阵列芯片现场高灵敏同步快速检测粮油中氨基甲酸酯类农药残留混合污染

农产品质量安全是国家乡村振兴战略的重点和难点。氨基甲酸酯类农药残留严重威胁粮油产品质量安全与人民生命健康。目前,常用的氨基甲酸酯类农残检测方法主要是仪器检测法,无法满足现场对粮油农残混合污染进行现场高灵敏同步快速检测的需求。本研究在前期自主选育的克百威和甲萘威单克隆抗体基础上,研究并制备出农残混合污染同步快速检测阵列芯片,建立了一种现场高灵敏同步快速检测技术,实现了在30 min内同步定量克百威和甲萘威。经过优化,克百威和甲萘威的检测限分别为0.11、0.09 ng/g,线性范围为0.33～3000 ng/g、0.18～1500 ng/g。在花生样品检测中,克百威和甲萘威的加标回收率分别为88.4%～98.3%和90.1%～118.8%;批内差(RSD)分别为9.0%和3.5%;批间差(RSD)分别为12.3%和16.3%。该阵列芯片检测结果与液相色谱-质谱联用(HPLC-MS/MS)检测结果高度一致。该阵列芯片满足了对农产品中克百威和甲萘威进行现场高灵敏同步快速检测的需求,并可广泛应用于农产品质量安全、食品安全以及环境监测等领域。     

The influence of post-exposure temperature on the toxicity of insecticides to Ostrinia nubilalis (Lepidoptera: Crambidae)

The influence of post-treatment temperature on the toxicities of two pyrethroids (lambda-cyhalothrin and bifenthrin), a carbamate (methomyl) and a spinosyn (spinosad) to Ostrinia nubilalis (Hubner) larvae was evaluated in laboratory assays. From 24 to 35 degrees C, the toxicities of the pyrethroids decreased 9.5- and 13.6-fold while spinosad toxicity decreased 3.8-fold. The toxicity of methomyl did not change significantly. The results demonstrate that the most effective insecticide against a pest may vary with environmental conditions. In situations where comparable products from multiple insecticide classes are available, temperature should be included as a factor in the decision-making process.     

氨基甲酸苯丙酮肟酯类化合物的合成及生物活性

为寻找高活性的新农药化合物,以3-取代氨基-1-芳基丙酮-1-肟与氨基甲酸酯反应,设计并合成了19个氨基甲酸苯丙酮肟酯衍生物,其结构均经核磁共振氢谱和元素分析确证。初步的生物活性测定结果表明,化合物具有一定的生物活性,其中 c11 在浓度为500 mg/L时,对蚜虫Aphis craccivora的致死率达到90%以上; c16和c17 在1 000 mg/L时,对朱砂叶螨Tetranychus cinabarinus 的致死率达到100%。