鸡蛋中氟虫腈及其代谢物残留分析方法

采用超高效液相色谱-串联质谱技术,以鸡蛋为研究对象,建立一种高效测定鸡蛋中氟虫腈及其代谢物残留测定方法。样品用乙腈提取,并通过固相萃取技术对样品进行净化处理,供超高效液相色谱-串联质谱仪进行检测。实验结果表明,该方法能够有效地分离和测定氟虫腈及其代谢物残留。在3个不同的添加水平(0.005、0.010、0.020 mg/kg)下,4种农药的回收率范围为81.3%~92.5%,相对标准偏差均低于5.5%。;在0.001~0.050μg/mL浓度范围内,线性关系良好,相关系数均大于0.990 4;氟虫腈、氟甲腈、氟虫腈砜与氟虫腈亚砜的检出限分别为0.001、0.002、0.002、0.002 mg/kg。该方法准确、灵敏、快速,可满足对鸡蛋中氟虫腈、氟甲腈、氟虫腈砜与氟虫腈亚砜4种药物残留的检测需要。

农药氟虫腈与钛白粉副产盐资源化生产电池用磷酸铁工艺

针对农药氟虫腈与钛白粉生产过程中副产盐的处置难题,提出以副产磷酸钠为磷源,以副产硫酸亚铁为铁源,制备电池级磷酸铁的工艺路线。采用连续催化氧化的方法将磷酸钠废盐中的亚硫酸钠氧化为硫酸钠,副产硫酸亚铁经过除杂后,用双氧水将硫酸亚铁氧化为硫酸铁,再与上述的磷酸钠反应得到磷酸铁。结果表明:亚硫酸钠的氧化率接近100%;副产硫酸亚铁经化学除杂和水解除杂后,杂质镁、锰、钛的质量分数分别降低至80 mg·kg^(-1)以下,杂质铝则被完全去除;除杂后的硫酸亚铁溶液经双氧水氧化后,硫酸亚铁的氧化率达到100%;制备得到的二水合磷酸铁的各项指标均满足标准HG/T 4701-2021《电池用磷酸铁》的要求。

基于不确定度评估研究ID-LC-MS/MS法检测鸡蛋中氟虫腈砜残留量的关键控制点

为了控制检测结果准确性,以鸡蛋粉中氟虫腈砜残留分析标准物质[GBW(E)100779]为测试样,采用“自下而上”法对基于多功能净化柱(PAC柱)净化的同位素稀释液相色谱串联质谱(ID-LC-MS/MS)法进行测量不确定度评估。“鱼骨图”分析表明,不确定度分量主要来源有样品称样量、内标溶液添加体积、标准工作溶液浓度及其移取体积。内标溶液添加体积引入的不确定度最大,对检测结果不确定度的贡献率为68.59%;万分之一天平称量引入的不确定度可忽略不计。同位素内标的添加过程是ID-LC-MS/MS法检测的关键控制点,参考基准的合理选择和目标物的完全提取是准确测量的前提。进一步用LC-MS/MS法对参考物质、稀释剂和内标溶液的适用性进行了评估,并基于国家有证标准物质[GBW(E)100779]对提取方法进行了优化。研究结果有利于提升鸡蛋食品安全的检测质量和质控水平,为精准检测质控方案的设计提供新思路。

GABA靶标杂环杀虫剂FIPRONIL对卫生害虫的活性研究

目的 :研究作用机制独特的新型杂环杀虫剂FIPRONIL对蚊、蝇、蠊 3种卫生害虫的活性 ,评价其在卫生害虫防制领域中应用的实际意义。方法 :微量点滴法、浸液法、药膜法、密闭圆筒喷雾法。结果 :FIPRONIL对淡色库蚊、家蝇及德国小蠊的致死性均优于拟除虫菊酯中的两种代表性杀虫剂氯菊酯和胺菊脂 ,击倒性则反之。对淡色库蚊幼虫的LC50 为 0 .0 1162 ppm ,对家蝇、德国小蠊的LD50 分别为 0 .0 0 371、0 .0 0 377μg/虫。结论 :FIPRONIL具备对 3种卫生害虫的高效毒力及无交互抗性的独特作用机制 。

GABA靶标杂环杀虫剂FIPRONIL对卫生害虫的活性研究

研究新型杂环杀虫剂FIPRONIL对蚊蝇蟑三种卫生害虫的活性 ,评价其在卫生害虫防治领域中应用的实际意义。结果表明 ,FIPRONIL对于淡色库蚊、家蝇及德国小蠊 ,致死性均优于拟除虫菊酯中两种代表性杀虫剂———致死型杀虫剂氯菊酯与击倒型杀虫剂胺菊脂 ,击倒性则反之。对淡色库蚊幼虫LC5 0为 0 0 116 2ppm ,对家蝇LD5 0为 0 0 0 371μg/虫 ,对德国小蠊LD5 0为 0 0 0 377μg/虫。FIPRONIL由于对三种卫生害虫的高效毒力及无交互抗性的独特作用机制 。

基质效应对芹菜中氟虫腈及其代谢物准确定量的影响

目的:为了探究基质效应对芹菜中氟虫腈及其代谢物(氟甲腈、氟虫腈亚砜和氟虫腈砜)准确定量影响程度。方法样品经QuEChERS前处理后获得空白基质溶液,对基质标准系列工作液和溶剂标准系列工作液分别进行GC-MS/MS检测并计算基质效应;做三水平加标实验(0.02 mg/kg,0.05 mg/kg和0.10 mg/kg),用不同曲线校正最终数据,比较不同校正方式对数据准确定量的影响。结果:4种农药的溶剂曲线和基质曲线线性良好,相关系数均>0.995。氟甲腈、氟虫腈亚砜、氟虫腈砜、氟虫腈在芹菜基质中的基质效应分别为1.58%,14.72%,20.06%,49.37%,均呈现基质增强效应。结论:在实际检测中,为了减小基质效应造成的数据误差,需要根据待测组分以及待测物种类选取合适的空白基质配制标准曲线,以提高检测的准确性。

QuEChERS-高效液相色谱串联质谱法检测鸡蛋中金刚烷胺、金刚乙胺、氟虫腈及其代谢物残留

建立了采用QuEChERS结合高效液相色谱-串联质谱法,快速测定鸡蛋中的金刚烷胺、金刚乙胺、氟虫腈及其代谢物残留量的方法。鸡蛋样品经水^(-1)%甲酸乙腈涡旋提取、盐析、QuEChERS净化后,以A Venusil MP C18色谱柱为分析柱,0.1%甲酸水-乙腈为流动相,进行梯度洗脱,采用正负离子喷雾模式电离,多反应离子监测方式进行定性及定量分析。在0.1~20.0ng·mL^(-1)的线性范围内,6种化合物的回归方程均呈良好的线性关系,相关系数r>0.9995。金刚烷胺、金刚乙胺、氟虫腈、氟虫腈砜、氟虫腈亚砜、氟甲腈的检出限,分别为0.5、0.5、0.1、0.1、0.1、0.1μg·kg^(-1),在低、中、高3组浓度水平下,平均加标回收率在81.1%~113.0%之间,相对标准偏差(RSD)在0.2%~9.2%之间。该方法的前处理简单易操作,检测速度快,检测灵敏度和准确度高,重现性好,可以满足同时快速检测鸡蛋中金刚烷胺、金刚乙胺、氟虫腈及其代谢产物残留的需求。

QuEChERS-气相色谱-负化学电离源-串联质谱法测定茶叶中氟虫腈及其代谢物的残留量

取2.00 g茶叶样品,用10 mL水浸泡,再用10 mL乙腈、QuEChERS萃取盐包(含6 g硫酸镁、1.5 g乙酸钠)离心提取。吸取8 mL上清液,加到QuEChERS净化盐管[内装1200 mg硫酸镁、400 mg N-丙基乙二胺(PSA)、400 mg C_(18)和200 mg石墨化碳黑(GCB)]内,振荡、离心,取上清液,过0.45μm滤膜后,采用气相色谱-负化学电离源-串联质谱法(GC-NCI-MS/MS)测定滤液中氟虫腈及其代谢物氟甲腈、氟虫腈砜和氟虫腈亚砜的含量,基质匹配法定量。结果表明,氟虫腈及其代谢物的质量分数均在0.005~0.50 mg·kg^(-1)内与其对应的峰面积呈线性关系,检出限(3S/N)为0.25~0.5μg·kg^(-1)。按照标准加入法进行回收试验,回收率为96.6%~136%,测定值的相对标准偏差(n=6)均小于7.0%。方法用于分析100批茶叶,在某一批次茶叶样品中检出氟虫腈及其代谢物,总量为77.1μg·kg^(-1)(以氟虫腈计)。

工程化学“产教融合”的实践——农药氟苯唑生产工艺的改进

随着当前教育改革的不断深化,应用型高校逐渐向着产教融合模式发展。以培养学生解决问题的能力为导向,对化学相关课程进行重新建设规划。课堂教学专注于对知识的理解和诠释,而企业则以生产成本和产品利润为导向,两者之间交流的缺乏会导致学生对课堂知识难以学以致用。在工程化学教学过程中,我们将农药氟苯唑生产实践与课堂教学相结合,作为教和学的研究课题,通过优化化学反应过程来提高生产效益。这些实践不仅完善了教师的教学内容,也加深了学生对基本原理的理解。在应用的过程中也极大地提高了学生们学以致用的兴趣。

超高效液相色谱串联质谱法测定鸡蛋中金刚烷胺和氟虫腈的含量

目的:建立超高效液相色谱串联质谱法测鸡蛋中金刚烷胺和氟虫腈的方法。方法:在样品溶液中加入内标工作液,用乙腈提取,经QuEChERS净化管净化;金刚烷胺采用正离子扫描,内标法定量;氟虫腈采用负离子扫描,外标法定量。结果:金刚烷胺、氟虫腈在0.20~20.00 ng·mL^(-1)时线性关系好,待测物的回收率在85.0%~103.3%,精密度在1.6%~8.9%,金刚烷胺定量限为2μg·kg^(-1)、氟虫腈定量限为5μg·kg^(-1)。结论:本方法准确度高、灵敏度高、稳定性好、操作简单,可以快速有效地测定鸡蛋中金刚烷胺和氟虫腈的含量。

超高效地下地上害虫防治新药──Fipronil

Ｆｉｐｒｏｎｉｌ是一种对许多类作物或非作物的地下及地上害虫具有优异防治效果的新型杀虫剂。Ｆｉｐｒｏｎｉｌ以１２０ｇ／１０￣４ｍ￣２剂量拖于土壤内，能有效防治玉米根叶甲、金针虫和地老虎；以２５—５０ｇ／１０￣４ｍ￣２喷雾可有效防治马铃薯甲虫、小菜蛾等多种咀嚼式口器害虫；以５０ｇ／１０ｍ￣２处理水稻可很好地防治螟虫、褐飞虱和稻水象甲。且对菊酯、有机磷、氨基甲酸酯及环戊二烯类农药无交互抗性，因此，Ｆｉｐｒｏｎｉｌ对抗性害虫的防效甚佳。

荧光标记法研究鱼类GABA受体与Ro7-1986/1和Fipronil的相互作用

以苯二氮卓类化合物Ro7-1986/1和氟虫腈(Fipronil)分别与异硫氰酸荧光素(FITC)反应合成了2种γ-氨基丁酸(GABA)受体的配体荧光复合物,即FITC-Ro7-1986/1(简称FITC-Ro7)和FITC-Fipronil;利用傅里叶变换红外光谱(FTIR)和核磁共振氢谱(1H NMR)等手段对其结构进行了表征.以2种荧光配体为探针,采用荧光标记法研究了Ro7-1986/1和Fipronil与鳙鱼(Hypophthalmichthys nobilis)脑内GABA受体的相互作用,得到了亲和常数Kd和最大结合量[RT].同时考察了GABA对Ro7-1986/1与受体相互作用的影响.研究结果表明,Ro7-1986/1和Fipronil与受体的亲和常数Kd分别为(67±5)nmol/L和(346±6)nmol/L;最大结合量[RT]分别为(13.8±1.8)pmol/mg protein和(40.6±3.5)pmol/mg protein;GABA促进了Ro7-1986/1与受体的结合,进一步的研究结果表明,鱼类与哺乳动物脑中GABA受体结构相似;相对于哺乳动物,苯吡唑类杀虫剂Fipronil对鱼类GABA的亲和力较高.

Degradation of Chlorpyrifos and Fipronil in Rice from Farm to Fork and Risk Assessment

Degradation of pesticide residues （chlorpyrifos and fipronil） in rice from farm to fork and risk assessment for human health were studied to reveal the magnitude of risks faced by different populations of interest, so that appropriate measures can be taken to control the risks, and to refine and update the human health risk assessment data while helping to determine the maximum residue level （MRL） value and harvest interval. Different dosages and treatments were used in field trials for the harvest residue test. Residue levels of postharvest-applied chlorpyrifos and fipronil during storage, exposure to sunlight, washing and boiling processes （boiled rice） were investigated for brown rice. The dietary exposure evaluation model （DEEM） was employed to estimate acute and chronic risks faced by different populations of interest. Percent of reference dose （POR） and margin of exposure （MOE） were calculated. A positive correlation between pesticide residues and the dosage and application frequency of pesticide was found in the field trials. Risk quotients indicate that multiple applications and double dosages of chlorpyrifos increase the risks to the entire population and prolong exposures to toxic concentrations. The concentration of pesticide residues decreased as a function of time, after sunlight exposure, storage, washing, and boiling processes. 91.6 and 96.16% degradations were achieved at the end of the experimental period for fipronil and chlorpyrifos, respectively. The boiling process played an important role in the degradation of these pesticides. The result of risk assessment to human health showed that harvest residues of chlorpyrifos in rice and acute dietary risks of chlopyrifos were of concern. The acute dietary （food only） risk estimated for chlorpyrifos as percent of acute population adjusted dose （aPAD） was frequently over 100%. The risk faced by boys under the age of 14 was higher than that for girls of the same age. For the subpopulation above age 14, the risk reversed. The chronic dietary risk from food alone showed that dietary exposures with fipronil were below the level of concern for the entire population, including children. The risk faced by rural residents was more serious than that for urbanite residents with the most sensitive populations being children and male residents who faced higher acute dietary risk than the other subpopulation groups. The harvest interval was found to be the critical measure to mitigate risk for all populations for safe rice eating. All risk levels decreased to acceptable levels when the harvest interval was extended to 14 d. To address these risks, a number of measures including reduced application rates （should not be doubled at single application）, increased retreatment intervals （longer than 7 d） and extended interval of harvest （at least 14 d） will be needed. The MRL for fipronil in rice is recommended to be 0.01 mg kg 1 in accordance with Codex （ref）.

Preliminary Study on Resistance of the Rice Stem Borer (Chilo Suppressalis) to Fipronil

By means of topical application, fipronil resistance was surveyed in the rice stem borer, Chilo suppressalis, from 12 diferent areas in east China from 2001 to 2004. The rice stem borers in most regions of Jiangsu and Anhui were still susceptible to fipronil. But in Wuxi, Jiangsu Province and Cixi, Zhejiang Province, their sensitivity became decreased （resistance ratios were 3.1 and 3.6, respectively）, and the medium level of resistance （resistance ratio was 21.2） was found in Cangnan, Zhejiang Province. So, it was still at the early stage for fipronil resistance development in this pest. Synergism experiments showed that piperonyl butoxide（PBO） had a little effect on both susceptible and resistant borers （synergism ratios were 1.1-1.2）. Though triphenyl phosphate （TPP） and diethyl meleate （DEM） had no effect on the susceptible borers, they had significant synergism on fipronil in the resistant population to fipronil （synergism ratios were 1.8 and 1.6, respectively）, indicating esterase and glutathion S-transferase may be involved in the resistance mechanism. Bioassay with currently used insecticides indicated that triazophos （because of high resistance）, trichlorphon and acephate had very low toxicity to resistant borers. But diazinon, pyridaphenthion, decamethrin and avermeatin showed high toxicity and had no cross resistance to fipronil, which could be considered as substitute insecticides in the resistance managment.

Experiment and Modeling of Pure and Binary Adsorption of n-Butane and Butene-1 on ZSM-5 Zeolites with Different Si/Al Ratios

Four ZSM-5 zeolite catalysts with different Si/Al ratios for the catalytic cracking of C4 fractions to produce ethylene and propylene were prepared in this study.First,the adsorption isotherms of pure n-butane and butene-1 and their mixtures on these catalysts at 300K and p=0—100kPa were measured using the intelligent gra- vimetric analyzer.The experimental results indicate that the presence of Al can significantly affect the adsorption of butene-1 than that of n-butane on ZSM-5 zeolites.Then,the double Langmuir(DL)model was applied to study the pure gas adsorption on ZSM-5 zeolites for pure n-butane and butene-1.By combining the DL model with the ideal adsorbed solution theory(IAST),the IAST-DL model was applied to model the butene-1(1)/n-butane(2)binary mixture adsorption on ZSM-5 zeolites with different Si/Al ratios.The calculated results are in good agreement with the experimental data,indicating that the IAST-DL model is effective for the present systems.Finally,the adsorp- tion over a wide range of variables was predicted at low pressure and 300K by the model proposed.It is found that the selectivity of butene-1 over n-butane increases linearly with the decrease of Si/Al ratio.A correlation between the selectivity and Si/Al ratio of the sample was proposed at 300K and p=0.08MPa.

Field Efficacy Test of 22% Fipronil FS against Sugarcane Stem Borers and Thrips

[ Objective] The paper was to explore the field efficacy of 22% fipronil FS against sugarcane stem borer and thrips （Baliothrips serratus Kobus ）. [ Method] The field trial was conducted by foliar spraying of 22% fipronil FS and mixed broadcasting with fertilizer in 2014. [ Result ] Foliar spraying of 22% fipronil FS at the dose of 50 mIV667 m~ had the best control effect against sugarcane stem borer, and the control effect at 90 d post administration was 70.70%, significantly higher than that of control agent （61.86%）. Medium and high dose of 22% fipronil FS had better control effects against sugarcane thrips. [ Conclusion ] Considering control effects against sugarcane stem borers and thrips as well as sugarcane yield, it is recommended that 22% fipronil FS is sprayed at medium concentration （50 mL/667 m2 ）.

Cross metathesis of butene-2 and ethene to propene overMo/MCM-22-Al_2O_3 catalysts with different Al_2O_3 contents

A series of 3.0Mo/MCM-22-Al2O3 catalysts with γ-Al2O3 contents in the range of 0-100 wt% were prepared and applied in the metathesis reaction of ethene and butene-2. Addition of γ-Al2O3did not affect the structure of MCM-22 zeolite as evidenced by XRD and N2 adsorption measurements. It was deduced from TPR experiments that γ-Al2O3 phase favored the formation of polymolybdate or multilayered Mo oxide, while more Al2（MoO4）3 species were generated over MCM-22 zeolites. Alumina content in the support was directly related to the metathesis activity of ethene and butene-2 to propene. Mo species with higher valence （Mo6＋or Mo5＋） contributed more to the excellent performance of catalyst than metallic Mo. The best catalyst activity and stability was obtained over 3.0Mo/（MCM-22-30%Al2O3） under the reaction condition of 1.0 MPa and 125℃ using N2 as the pretreatment gas.

Research Progress of Termite Control with Fipronil

The indoor and field control effect of fipronil against termite was introduced, and the main influencing factors were analyzed, including traverse transfer of fipronil between termite individuals, temperature and proportion of termite exposed to fipronil, synergistic effect of other agents on fipronil, diffusion and degrada- tion of fipronil in soil. The effects of fipronil and metabolites on environment were elaborated.

Additive Efficiency of Fipronil + Methoprene Compared to Fipronil Alone against <i>Rhipicephalus sanguineus</i>Ticks in Naturally Infested Dogs

The acaricidal efficiency of fipronil alone and fipronil + methoprene compared to commercial fipronil and commercial fipronil + methoprene, applied by the epicutaneous route (spot-on) in dogs naturally infested with ticks, was assessed. Thirty dogs infested with high loads of ticks were used. On day 0, the dogs were divided into 5 groups of 6 animals each. Each animal was duly identified for individual and group monitoring. Treatments were made based on body weight according to manufacturer’s instructions. Group 1 (G1) received 10.0% fipronil at a single dose of a pipette applied by epicutaneous route in the base of the neck. G2 received 10% fipronil + 10% methoprene in single application similarly to G1. G3 was treated with 9.8% commercial fipronil as before mentioned. G4 received commercial 9.8% fipronil + 9.8% methoprene applied as in previous groups. G5 served as an infected untreated control. Animals were examined by thumb tick counts on days 0 (Treatment day), 3, 7, 14, 21 and 28. Efficacy was measured as a percentage of tick reduction in the treated groups relative to the untreated control. Results indicated an overall efficacy of 88.2%, 93%, 90.4% and 99.3%, respectively. There was no significant statistical difference between the treated groups (P < 0.05), neither in sex nor in weight. Engorged ticks were the most frequent, followed by the nymph group. However, by the end of the study these data were reversed due to the fact that only small larvae were found, which we interpreted came from engorged ticks that released their progeny before dying and a month later their offspring began to be observed presently and in full development. It is concluded that the combined formulations of fipronil + methoprene compared to fipronil applied alone, showed an additive effect against Rhipicephalus sanguineus ticks in naturally infested dogs kept in captivity.

Analysis of Operating Variables in the Catalytic Purification of Butene-1 in a Trickle Bed

A mathematical model for analyzing and simulating selective hydrogenation of butyne-1 and 1,3-bu-tadiene in industrial trickle bed reactors operated to obtain high purity butene-1 is presented in this work.Fromthe analysis of typical operating conditions,only the relevant phenomena are finally retained in the model formu-lation.The model is then employed to analyze the effect of operating variables and catalyst selectivity in processperformance.In particular,the search for the minimum hydrogen flow rate necessary to fulfil butene-1 purityspecifications is undertaken.