Removal of imidacloprid and acetamiprid from tea infusions by microfiltration membrane

Removal of imidacloprid and acetamiprid in tea infusions by microfiltration membrane using dead‐end model was investigated in the present study. The results showed that microfiltration significantly promoted the removal of both pesticides (P < 0.05) in tea infusions. Furthermore, the extent of removal was strongly influenced by the pore size of membrane, operational pressure and the concentrations of tea infusions. The initial concentration of imidacloprid and acetamiprid showed no significant effect on their removal rates. The maximum removal rates were 79.7% for imidacloprid and 81.9% acetamiprid. The changes in major chemical components of tea infusions after microfiltration were evaluated. The results indicated that microfiltration caused no considerable changes in total polyphenols and total free amino acids, and small but statistically significant losses (6.3–18.0%) of eight catechins and three methylxanthines when filtration volume reached to 200 mL. The present study validated the application of microfiltration as a potentially feasible and promising method for the removal of imidacloprid and acetamiprid residues from tea infusions.     

液相色谱-串联质谱法测定冬枣中多菌灵、啶虫脒残留量

本文研究建立了冬枣中多菌灵、啶虫脒的液相色谱串联质谱测定方法。样品用甲醇直接提取,提取液注入液相色谱串联质谱仪中进行检测。利用ESI源(正离子模式),C18液相色谱柱(100mm×2.1mm,3μm),以及SRM(选择反应监测)方法对样品中的多菌灵、啶虫脒进行定性、定量分析。多菌灵母离子为192,定量离子对为192159.9,定性离子对为192131.9,192104.9,啶虫脒母离子为223.2,定量离子对为223.2126,定性离子对为223.299,223.290.1。该方法测定结果的相对标准偏差小于4%(n=6),平均回收率大于90%,线性范围为1-10ng/mL,最低检出限多菌灵为0.15ng/mL,啶虫脒为0.39ng/mL。     

Reduction of methomyl and acetamiprid residues from tomatoes after various household washing solutions

The removal of pesticide residues is essential in order to control and reduce the harmful effects of pesticides commonly used in agriculture. The aim of this study was to investigate the effectiveness of 18 different household washing solutions for the reduction of methomyl and acetamiprid residues from tomatoes. These basic household solutions were used to prepare washing solution to remove pesticides. During this study, tomatoes were divided into two groups: in the first group, tomatoes were treated with the pesticides and the second group was washed with household solutions (distilled water, acetic acid, sodium chloride, ethanol, sodium bicarbonate, hydrogen peroxide, sodium hypochlorite, and liquid soap, lemon juice, mineral water, zam-zam water, whey, milk, and their combinations) after treating with pesticides. The pesticides residues in all samples were extracted by the QuEChERS technique, analyzed by LC-MS/MS. The results showed significant reduction in residues of all washed groups compared with the control (p < 0.01). Acetic acid, sodium chloride+sodium bicarbonate, zam-zam water, acetic acid+sodium chloride, sodium hypochlorite, milk, acetic acid+sodium chloride+sodium bicarbonate, liquid whey, liquid soap, lemon juice, ethanol, and sodium bicarbonate were found to remove more than 50% of both pesticide residues. The effectiveness of washing solutions was different for every type of pesticide. In the same way, blend of washing solutions has shown a synergetic effect on the removal of pesticides and was more effective compared to one solution. This research has raised the potential use of household solutions easily found at home that could be used to remove pesticide residues.     

LC–MSMS analysis of acetamiprid residue in crude palm oil

A method for acetamiprid residue detection and quantification in crude palm oil (CPO) using LC–MSMS after the clean‐up with graphite packed SPE was developed. This method was validated in house and passed all important validation tests such as linearity, intermediate precision, and repeatability test. The limit of detection and quantification of the method were estimated from an acetamiprid standard calibration curve and the values were 4 and 10 ng/g, respectively. To examine the efficiency of the developed method, recovery experiment was carried out at the method limit of quantification using CPO, crude sunflower oil, crude rapeseed oil, and refined soybean oil. Results showed that this method was suitable for the analysis of acetamiprid residue in these oils with the recoveries ranged from 79 to 116%.     

Efficacy of d-tetramethrin and acetamiprid for control of Trogoderma granarium Everts (Coleoptera: Dermestidae) adults and larvae on concrete

The khapra beetle, Trogoderma granarium Everts (Coleoptera: Dermestidae) is a dangerous insect of stored products that has currently expanded in Africa, Asia and Europe. Control of this species encounters difficulties when synthetic insecticides are applied either as surface treatments or as grain protectants. Therefore, new insecticidal formulations should be assessed as additional tools towards an effective management of T. granarium. In the current study, we tested the new insecticidal formulation Dobol, that contains the pyrethroid insecticide d-tetramethrin and the neonicotinoid insecticide acetamiprid, as treatments on concrete. Their direct and delayed mortality against adults and larvae of T. granarium were estimated under two label doses (min and max) and two temperature levels (30 and 35 °C) after 1, 2, 3, 4 and 7 d of exposure interval. Results revealed that Dobol caused direct mortality to T. granarium adults that ranged between 87.8 and 96.7%. Concerning larvae, direct mortality was generally much lower, being at most 84.4% at the max dose after 7 d of exposure. Temperature had significant impact on the direct mortality of T. granarium adults and larvae within the vast majority of the tested exposure intervals at both doses. However, when the surviving adults and larvae were transferred on untreated concrete surfaces, despite higher mortality at 35 than 30 °C, there was no significant impact of temperature on their mortalities within any exposure interval and dose. Our study revealed that Dobol is a promising insecticidal formulation that can be effectively used against adults and larvae of T. granarium on concrete surfaces.     

反相高效液相色谱法测定杨树中吡虫清残留量

建立高效液相色谱法测定吡虫清(Acetamiprid)含量,实验采用C18柱(250×4.6mm)30%乙腈+70%水(pH≈3),流速0.8mL/min,UV检测波长为270 nm,检测限为0.01mg/L,线性方程为Y=2344.3X+30979.6,相关系数r=0.9999,方法回收率为96.2%~98.6%,相对标准偏差RSD=0.46%(n=6)。     

啶虫脒在超高交联吸附树脂上的吸附及脱附性能研究

本文从动态和静态的角度研究了均苯四甲酸酐修饰的超高交联吸附树脂（PMAR）和1,2,4-苯三酸酐修饰的超高交联吸附树脂（TMAR）对啶虫脒的吸附和脱附行为。结果表明：两种树脂对啶虫眯的吸附和脱附效果都比较好,TMAR的静态吸附量为470．9mg·g^-1干树脂,饱和吸附量为562．7mg·g^-1干树脂;PMAR的静态吸附量为453．4mg·g^-1干树脂,饱和吸附量为559．1mg·g^-1干树脂。两种树脂都易于脱附,用2mol·L^-1 HCl：乙醇（体积比1：1）作脱附剂,温度323K,脱附剂体积为9．5BV（床体积）时,PMAR的脱附率为98．13％,TMAR的脱附率为99．83％。     

吡虫清的合成

吡虫清是一种氯代烟碱类优良杀虫剂。它比吡虫啉杀虫谱更广,效果更好。吡虫清的合成有四种方法。本文用２－氯－５－氯甲基吡啶经氨基化,和Ｎ－氰基乙亚胺酸乙酯反应,最后甲基化得到吡虫清。总收率为５７％（以２－氯－５－氯甲基吡啶计）,含量〉８５％。     

一株啶虫脒降解菌AC04的鼠类急性毒性评价

目的对从长期种植枸杞的土壤中分离筛选出的一株可高效降解农药啶虫脒的细菌AC04进行急性毒性的安全性评价。方法将提取的AC04菌液对小鼠进行经口灌胃急性毒性实验;将表面喷洒菌悬液的枸杞对大鼠进行30 d喂养实验。结果 经口急性毒性实验中实验小鼠行为、进食均正常,未出现中毒及死亡情况。观察期结束后,解剖动物主要脏器、器官,均未见明显异常改变。大鼠30d喂养实验中,实验动物的体征外观、行为、体重、血象等各项指标均正常,无明显中毒症状或不良反应。结论 该菌株及其代谢产物对试验鼠未见明显毒性。