Field Efficacy Trials of 1%Bifenthrin·thiamethoxam GR against Sweet Potato Weevil

[Objectives]The paper was to verify the field efficacy of 1%bifenthrin·thiamethoxam GR replacing organophosphorus GR against sweet potato weevil and its impact on the yield and quality of sweet potato.[Methods]A total of 4 field trials were conducted in Guangdong Province,including 1%bifenthrin·thiamethoxam GR applied at the doses of 3,4 and 5 kg/667 m^(2),and 3%phoxim GR applied at the dose of 4 kg/667 m^(2).[Results]1%Bifenthrin·thiamethoxam GR applied at the dose of 5 kg/667 m^(2)had excellent control effects on sweet potato weevil,with an average control effect of 77.60%,which was significantly higher than that of 3%phoxim GR applied at the dose of 4 kg/667 m^(2)(48.52%).And the average yield increase rate of sweet potato treated with 1%bifenthrin·thiamethoxam GR reached 24.79%,significantly higher than 12.37%in the control group.[Conclusions]1%Bifenthrin·thiamethoxam GR should be evenly distributed on the ridge surface near sweet potato within 5-7 d after planting,and the recommended dosage is 5 kg/667 m^(2),which will have good control effect on sweet potato weevil and increase the yield of sweet potato.

Preparation and Characterization of Bifenthrin Nanoemulsions

[ Objective] The paper was to prepare bifenthrin nanoemulsions, and to characterize its property. [ Method ] Oil in water type of bifenthrin nanoemul- sions was prepared using emulsion phase transition method at constant temperature of 25℃. The formation mechanism of nanoemulsions was investigated, and the property of bffenthrin nanoemulsions was characterized by dynamic light scattering（DIS）, transmission electron microscopy （TEM）, contact angle meter, interfa- cial tension meter and high performance liquid chromatogTaphy （HPLC）. [ Result ] Phase transition occurred during the formation progress of bifenthrin nanoemul- sions ; the particles of nancomulsions system was spherical, and the particle size was mainly distributed in the range of 25 -30 ran; the contact angle on paraffin was less than 90° with good wetting effect; the surface tension was less than 40 mN/m, and the emulsification effect was also good, so the utilization rate of bifenthrin nancomulsions was improved. HPLC results showed that bffenthrin was not easy to decompose or precipitate with good stability. [ Conclusion] The result provided basis for the preparation of new types of insecticides.

Chronic toxicity and cytotoxicity of synthetic pyrethroid insecticide cis-bifenthrin

With the increasing use of synthetic pyrethroids （SPs）, the significance of ecological safety and health risk is an emerging concern, In this study, we evaluated the chronic aquatic toxicity of eis-bifenthrin （cis-BF） in Daphnia magna and its cytotoxicity in Chinese hamster ovary （CHO） cells as well as human cervical carcinoma （Hela） ceils. Chronic aquatic toxicity tests showed that cis-BF could significantly affect the reproduction of D. magna. The lowest observed effective concentration and the non-observed effective concentration of cis-BF to D. magna were 0.02 and 0.01 μg/L, respectively, and the chronic value was 0.014 μg/L. The intrinsic rate of natural increase was significantly decreased （p 〈 0.05） to 0.02 μg/L. The cytotoxicity assay demonstrated that cis-BF decreased cell viability in CHO and Hela cells in a concentration- and time-dependent manner. The IC50 values for Hela and CHO cells were 4.0 × 10^-5 and 3.2 × 10^-5 mol/L, respectively. Together, these results indicated that cis-BF induced chronic toxicity in both aquatic invertebrate animals and mammalian cells. These findings assist in understanding the impact of SPs on health and environmental safety. Considering the wide spectrum of SPs, a more comprehensive understanding of the negative effects is indispensible for planning future application and regulation of these pesticides.

Effects of bifenthrin on Daphnia magna during chronic toxicity test and the recovery test

The acute and chronic toxic effects of bifenthrin on Daphnia magna were studied. The results showed that 24 h-EC 50 , 48 h-LC 50 and 96 h-LC 50 of bifenthrin on D. magna were 3.24, 12.40 and 1.40 μg/L respectively. And the LOEC and NOEC of bifenthrin were 0.02 and 0.004 μg/L respectively. The recovery test of bifenthrin on Daphnia magna was presented. Daphnia magna(F 0 generation) were exposed during 21 d to different bifenthrin concentrations. Offspring(animals from the first and third brood: F 1(1st) and F 1(3rd), respectively) were transferred to a free pesticide medium during a 21 d recovery period. In this recovery study, survival, growth, reproduction(mean total young per female, onset of reproduction and number broods per female) and the intrinsic rate of natural increase (r) were assessed as parameters. Reproduction such as number of young per female as well as length was still reduced in F 1(1st) generation daphnids from parentals(F 0) exposed to the bifenthrin. However F 1(3rd) individuals from parentals exposed to pesticide concentrations were able to restore reproduction when a recovery period of 21 d was allowed, but the length of F 1(3rd) from parentals exposed to the 0.5 and 0.75 μg/L bifenthrin concentration was still significantly effected(P<0.05).

Exposure to bifenthrin disrupts the development of testis in male Sebastiscus marmoratus

Bifenthrin（BF） is a pyrethroid insecticide that is widely used in agriculture, horticulture, and for residential purposes. However, few studies addressing the reproductive toxicity of BF on fishes are available. The present study was conducted to investigate the effects of BF on testicular development in Sebastiscus marmoratus and to gain insight into its mechanism. After exposure to 1, 10 and 100 ng/L BF for 50 days, there was a reduced number of mature sperm and an abundance of the late stages of spermatocysts in the testes. The levels of 17β-estradiol and testosterone were decreased significantly after BF exposure. The activity of caspase-3 was increased in a dosedependent manner after BF exposure, TUNEL assay indicated that BF exposure resulted in the occurrence of apoptosis in the testes, which might be main reason for the inhibition of spermatogenesis.

Analysis of Bifenthrin Degrading Bacteria from Rhizosphere of Plants Growing at Tannery Solid Waste

Bifenthrin is an insecticide which is used to control insects, mites, and ticks. It poses a solemn en-vironmental threat and health risk to living organisms. It may be bioaccumulated or biomagnified at different trophic levels in the food chain by biota. Microbes are hidden creature of earth’s biodiversity. For isolation of bifenthrin degrading bacteria, rhizospheric soil samples of plants like Pisum sativum, Triticun aestvum, Chenopodium album were taken from tannery solid waste, Kasur, Pakistan. Enrichment culture techniques were used for the isolation of bacterial strains that showed luxurious growth on minimal growth media with bifenthrin dose was selected for biodegradation study. Bacteria were further screened out based on their morphological, biochemical parameters and degradation efficiency. Furthermore the effect of different growth factors like temperature, pH, inoculum concencentration, minimal inhibitory concentration of heavy metals and antibiotics were also studied. Bacterial strains of Xanthomonas and Bacillus sp. were identified as efficient degrading microbes. Maximum bifenthrin utilization were observed at 25°C (pH 7), with 500 μL inoculum of Bacillus sp., while Xanthomonas sp. gave optimm utilization at 30°C (pH 7) at the same inoculum volume of bacteria. The Rf values of Bacillus sp. and Xanthomonas sp. were 0.91 and 0.90 respectively, which indicated their potential to metabolize bifenthrin into nontoxic forms. These strains can be used to clean up the sites polluted with pesticides and tannery wastes when present in rhizosphere of plants.

Characterizing Rhizodegradation of the Insecticide Bifenthrin in Two Soil Types

Rhizodegradation is a process by which plant-supplied substrates stimulate microbial populations in plant root zones (rhizospheres) to cause removal of undesirable levels of contaminants in soil. This study characterized rhizodegradation of the insecticide bifenthrin in Armour silt loam and Sullivan fine sandy loam soils that were planted with switchgrass, big bluestem, and alfalfa. After six weeks in soils, plate dilution frequency assays (PDFA) of bacterial populations were higher in all planted soils than in unplanted ones. Planted Sullivan soils contained higher bacteria than corresponding Armour soils and alfalfa rhizospheres of both soil types contained highest bacteria. Bacterial populations generally increased between week 6 and week 10, before declining in each treatment at week 12. Carbon utilization patterns (CUP) of bacterial communities, measured as color development on BIOLOG plates, were higher in planted soils than in unplanted ones. Principal Component Analysis (PCA) constructed patterns based on different extents of color development;these patterns were used to relate microbial communities in the different treatments. Gas chromatography (GC-ECD) showed that significantly more bifenthrin dissipated in planted soils than unplanted ones. Different levels of bifenthrin were recovered in planted soils but the differences were generally not significant. Data are being evaluated further to provide a basis for the development of strategies for enhancing rhizodegradation of soils contaminated with bifenthrin.

Protective effects of EGCG on Bifenthrin-Induced Oxidative Stress in the Human Embryonic Lung Fibroblast Cell Line HFL-I

Bifenthrin(BF) is an important type I synthetic fluorinated pyrethroid insecticide and acaricide.Previous investigations have indicated that the metabolisms of BF in human cells were through oxidative processes,and cytotoxicity was induced by the oxidative stress.In this study,the protective effects of EGCG,which is a major individual of green tea polyphenols,on the human embryonic lung fibroblast cell line HFL-I exposed to BF were investigated.The results showed that BF could induce oxidative stress leading to cytotoxicity in HFL-I cells.The pretreatment of EGCG at low concentrations significantly recovered the cell viability and morphology,inhibited excess generation of ROS,enhanced antioxidant enzyme activities and avoided loss of mitochondrial membrane potential.The results suggested that EGCG might eliminate the BF-induced damage in HFL-I cells.

绿茶中联苯菊酯和氯氟氰菊酯残留检测质量控制基体标准物质的研制

目的:制备一批绿茶中联苯菊酯和氯氟氰菊酯基体标准物质。方法:以绿茶为研究对象,通过喷洒联苯菊酯和氯氟氰菊酯,样品经粉碎、过筛、均质、装瓶,通过均匀性、稳定性检验后,由3家实验室联合定值确定量值,并进行不确定度评估。结果:绿茶中联苯菊酯和氯氟氰菊酯的量值分别为(0.185±0.0197),(0.207±0.0466)mg/kg,k=2,置信区间为95%。结论:研制出的绿茶中联苯菊酯和氯氟氰菊酯基体标准物质足够均匀,足够稳定,定值结果可靠。

联苯菊酯对皱纹盘鲍血细胞胞外陷阱形成的影响

为探究贝类细胞胞外陷阱对联苯菊酯(BF)胁迫的响应,实验以皱纹盘鲍血细胞为研究对象,探讨不同浓度BF(0、0.01、0.10、1.00 mg/L)对血细胞细胞活力、胞外陷阱(ETs)、活性氧(ROS)产量以及ROS、糖酵解相关基因表达量的影响。结果显示,皱纹盘鲍血细胞的细胞活力随着BF浓度升高分别降低至90.40%、80.22%和72.28%,具有一定的剂量依赖性特征。BF降低了皱纹盘鲍血细胞活力,且具有一定的剂量依赖性特征。不同浓度BF刺激后,pi3k表达量极显著上调,分别为对照的2.16、3.32和3.32倍。在0.01 mg/L BF刺激下,akt表达量极显著上调,在1.00 mg/L BF刺激下达到最高,为对照的5.34倍。在0.01 mg/L BF刺激下,hif-1α的表达量与对照组无显著差异,在1.00 mg/L BF刺激时升高最为显著,为对照的11.63倍。在BF诱导形成ETs过程中,血细胞ROS产量增加,且ROS相关基因表达量显著上调。通过添加烟酰胺腺嘌呤二核苷酸磷酸(NADPH)氧化酶抑制剂(DPI),发现ETs的形成受到抑制,表明ROS参与了ETs形成过程。同时,在ETs形成的过程中,糖酵解相关基因表达量显著提升,初步表明糖酵解反应参与到ETs的形成过程。与对照组相比,pk的表达量显著升高,在BF浓度为1.00 mg/L时表达量最高;hk的表达量在所有刺激浓度下均极显著升高,且在BF浓度为1.00 mg/L时表达量最高。研究表明,ROS和糖酵解反应参与了BF诱导的皱纹盘鲍细胞胞外陷阱发生过程,BF可能会通过干扰血细胞发挥正常的细胞免疫反应,继而对细胞造成一定的免疫毒害作用。

胶体金免疫层析法检测叶菜中联苯菊酯残留的应用

本文采用胶体金免疫层析法检测叶菜基质中联苯菊酯农药残留量,测试了检测灵敏度、特异性,并优化了检测过程的样品重量、提取液用量及稀释方法、固液分层方式及时间、孵育时间、反应时间等前处理方法条件。结果表明,胶体金法检测叶菜中联苯菊酯的检出限为4.0 mg/kg,与6种拟除虫菊酯类农药均无交叉反应。本文简化了操作步骤,采用静置的分层方式替代原有的离心操作,降低对场地、设备、器具的要求,为后续开发使用低精度量器进行前处理操作的产品提供技术基础。

375 g/L联苯菊酯·溴氰虫酰胺OD的高效液相色谱测定

建立了一种可用于测定375 g/L联苯菊酯·溴氰虫酰胺可分散油悬浮剂(OD)中有效成分的高效液相色谱分析方法。采用岛津Inertsil ODS-3 C_(18)柱为固定相,以甲醇+水溶液为流动相,在230 nm的检测波长下,对375 g/L联苯菊酯·溴氰虫酰胺OD试样中联苯菊酯和溴氰虫酰胺进行分离和分析。研究结果表明,在该色谱检测方法下,联苯菌酯和溴氰虫酰胺的线性相关系数均为0.9999,标准偏差分别为0.0957和0.0843,变异系数分别为0.50%和0.52%,平均回收率分别为99.35%和99.48%。说明该方法具有线性相关性好、精密度和准确度高等特点,可用于溴氰虫酰胺·联苯菊酯OD产品的质量分析检测。

湿润土壤中联苯菊酯残留的高效液相色谱检测

为提高房屋白蚁化学屏障质量检测工作效率,在长沙市5个工地基坑中喷洒不同药量的联苯菊酯悬浮剂,比较自然风干土样和湿润土样的药物残留值。结果表明:湿润土样和自然风干土样的联苯菊酯出峰时间基本一致;2种不同样品提取和计算得到的残留检测结果接近,平均误差值均小于3%,并且差异性不显著。综之可知,湿润土样不经过自然风干,直接进行样品提取和计算的方法适用于土壤中联苯菊酯悬浮剂残留量的检测。

亚急性浓度暴露下联苯菊酯对真鲷体内酶活性及肝细胞DNA损伤的影响

联苯菊酯是一种广泛应用的拟除虫菊酯类农药,但有关联苯菊酯对海水鱼类的毒性机理研究较少。为研究亚急性暴露下联苯菊酯对真鲷的毒性效应,在急性毒性试验基础上,选取5个浓度梯度对真鲷进行半静置暴露试验,测定不同暴露时间体内酶活性变化,并开展暴露25 d后肝细胞彗星试验。结果表明,亚急性暴露下真鲷血清中乙酰胆碱酯酶(AChE)、血细胞中Na^(+)-K^(+)-ATP酶(Na^(+)-K^(+)-ATPase)、肝和鳃中谷胱甘肽硫转移酶(GST)等酶活性先后出现了诱导或抑制现象。暴露浓度低于0.10μg·L^(-1),联苯菊酯对真鲷血清中AChE、血细胞中Na^(+)-K^(+)-ATPase和肝中GST等酶活性主要表现为诱导作用(P<0.05)。暴露浓度高于0.10μg·L^(-1),AChE活性受到显著抑制(P<0.05);暴露浓度高于0.20μg·L^(-1),Na^(+)-K^(+)-ATPase、GST活性均受到显著抑制(P<0.05)。与对照组相比,各暴露浓度组肝细胞DNA均有不同程度损伤,彗星拖尾率、彗星尾长、彗尾DNA相对含量、Olive尾距与对照组之间均差异显著(P<0.02)。回归分析显示,暴露浓度与各试验指标数据呈线性关系,R^(2)值范围在0.906~0.984之间。暴露浓度高于0.10μg·L^(-1)时,联苯菊酯可显著影响真鲷体内酶活性,并对肝细胞DNA产生不同程度损伤,具有一定遗传毒性和潜在生态风险。

3种有益菌对联苯菊酯残留晒青毛茶固态发酵过程中多酚类物质含量影响的研究

为了探明有益菌对联苯菊酯农药残留晒青毛茶固态发酵中茶多酚类物质含量的影响,以期为普洱茶固态发酵工艺的优化及普洱茶农药残留安全性标准的制定提供科学依据。采用高效液相色谱技术分析鉴定了不喷联苯菊酯不接菌、不喷联苯菊酯接酿酒酵母菌、黑曲霉、产黄青霉,喷施联苯菊酯后不接菌、喷施联苯菊酯后接酿酒酵母菌、黑曲霉、产黄青霉8种固态发酵处理下普洱茶茶多酚类物质含量。结果表明联苯菊酯农药的喷施使茶多酚类物质的含量极显著低于喷药前(P <0.01);喷联苯菊酯后接菌的发酵样中各时期茶多酚类物质含量极显著低于不喷联苯菊酯接菌的发酵样(P <0.01),极显著高于喷施联苯菊酯不接菌的发酵样(P <0.01)。联苯菊酯农药残留给普洱茶的滋味和安全带来不良影响,有益菌的利用可以降低茶多酚类物质含量的减少,为普洱茶的品质改善和安全性提供保障。

茶叶和土壤中cis-联苯菊酯、高效氯氟氰菊酯手性对映体残留分析

为了满足茶叶和土壤中手性农药cis-联苯菊酯和高效氯氟氰菊酯对映异构体残留检测的需要,本试验首次对比研究了正相液相色谱条件下,Daicel ChiralPak®AS-H、Phenomenex®Cellulose-1和Cellulose-3柱对两组手性对映体的拆分效果,以及气相色谱条件下BGB-172柱的分离测定效果,并建立了基于手性气相色谱分离的茶叶和土壤中cis-联苯菊酯和高效氯氟氰菊酯对映体残留分析方法。样品采用正己烷和丙酮提取,Florisil与GCB混合柱净化,气相色谱手性柱BGB-172程序升温分离,电子捕获检测器(ECD)外标法定性定量测定。结果表明,在2.5~800μg·L^(-1)浓度范围内,cis-联苯菊酯对映体色谱峰面积(Y)与浓度(x)之间分别满足线性方程Y=15381.1x-279657.5(r=0.9967)和Y=17387.6x-399048.0(r=0.9937),对映体分数(EF值)=0.489±0.017;在2.5~200μg·L^(-1)浓度范围内,高效氯氟氰菊酯对映体分别满足线性方程Y=22083.8x-161004.3(r=0.9923)和Y=23001.1x-167694.8(r=0.9922),EF=0.492±0.008。在0.005、0.050和0.50 mg·kg^(-1)3个添加浓度水平下,cis-联苯菊酯和高效氯氟氰菊酯对映体在不同茶叶、土壤样品中的平均添加回收率为61.6%~123.4%,相对标准偏差(RSD)为2.5%~14.6%,检测限低于0.001 mg·L^(-1),方法定量限低于0.005 mg·kg^(-1),不同样品中未见到明显基质效应。综上,该方法能够满足cis-联苯菊酯和高效氯氟氰菊酯对映体残留分析的需要,用于研究茶鲜叶中cis-联苯菊酯和高效氯氟氰菊酯对映体残留消解,且无明显对映体选择性差异。本研究结果为进一步开展2种手性农药在茶叶生长和加工过程中的残留和消解规律研究提供了技术支持。

离子液体-分散液液微萃取结合高效液相色谱法快速分析茯苓中氰戊菊酯和联苯菊酯农药残留

离子液体-分散液液萃取法被成功地应用于萃取和富集中药材茯苓中氰戊菊酯和联苯菊酯。1-辛基-3-甲基咪唑六氟磷酸盐([C_8mim][PF_6])作为萃取溶剂,1-丁基-3-甲基咪唑四氟硼酸盐([C_4mim][BF_4])为分散剂。整个萃取过程不需要加入任何有机溶剂,萃取过程快速,3min内就可以达到萃取平衡。茯苓中目标化合物的加样回收率在95.7%~98.3%之间,检出限为0.50和0.40 ng·mL^(-1)之间,结果令人满意,说明该实验方法适用于检测中药材中氰戊菊酯和联苯菊酯农药残留。

1%联苯·噻虫嗪颗粒剂对甘薯小象甲的田间防效试验

为探索新型1%联苯·噻虫嗪颗粒剂(颖壮)对甘薯小象甲的防效及对甘薯产量和品质的影响,于2021年在广东省湛江、汕尾和惠州开展了3个田间防效试验。结果表明:1%联苯·噻虫嗪颗粒剂5和6 kg/667m^(2)平均防效分别为78.56%和79.05%,与当地常规施药(多药剂联合多次施药)的平均防效79.22%相当,增产率分别为6.21%和7.17%,显著高于当地常规施药的增产率3.94%,商品薯率也较当地常规施药及空白对照有明显的增加。因此,1%联苯·噻虫嗪颗粒剂(颖壮)可以作为防治甘薯小象甲的高效低风险农药,在鲜食型甘薯生产上具有较大的应用潜力。

溴虫氟苯双酰胺与联苯菊酯复配对黏虫的联合毒力测定

为筛选出防治黏虫的高效杀虫剂,通过喷雾法测定了溴虫氟苯双酰胺和联苯菊酯复配对黏虫的联合毒力。结果表明:溴虫氟苯双酰胺和联苯菊酯以质量比5∶1、3∶1、1∶1、1∶3和1∶5复配对黏虫的共毒系数分别为122.37、141.50、102.19、114.68和117.11。综合考虑,3∶1为溴虫氟苯双酰胺和联苯菊酯混配的最佳配比。

马尾松木材联苯菊酯防腐浸泡工艺研究

为探索低成本、高效率的马尾松木材联苯菊酯防腐浸泡工艺,采用正交试验法,研究浸泡工艺对马尾松锯材增重率和联苯菊酯载药量的影响。结果表明:联苯菊酯浓度对增重率和载药量的影响最大,其次为浸泡时长,最后为浸泡深度,其中联苯菊酯浓度和浸泡时间对增重率和载药量有显著性影响。综合企业实际生产,本研究以时间为优化条件,确定的较优工艺为:联苯菊酯浓度0.05%、浸泡时长6 h、浸泡深度为50 mm。以此工艺浸泡的马尾松锯材,联苯菊酯载药量为0.059%,满足AS/NZS 1604.1:2021 Preservative-treated wood-based products Part 1:Products and treatment对联苯菊酯的限值要求。