常压法合成Methomyl的研究

提出一种合成Methomyl的改良法。该方法的特点是反应可在常压下进行。对常压反应的优宜条件作了系统研究,并讨论了反应机理。

两相法合成Methomyl的研究

报道一种合成Methomyl的两相法。此法能使甲硫基乙醛肟与甲胺基甲酰氯之间的缩合反应在两相界面上进行,从而有效抑制酰氯的水解,并使收率明显提高。

Solid phase extraction of methomyl and thiodicarb from environmental water with an activated carbon cartridge and their determination by HPLC

A solid phase extraction procedure of methomyl and thiodicarb from environmental water was presented. This method utilizes a 40—60 mesh activated carbon cartridge and high performance liquid chromatography (HPLC). The 40—60 mesh activated carbon works faster and yield higher adsorption efficiency. Detection limits of methomyl and thiodicarb in environmental water are 0 1 μg/L and 0 2 μg/L, respectively. Average recoveries of fortified methomyl and thiodicarb in water are in the range of 90 7%—98 8% and 88 9%—103 6%, respectively. The relative standard deviations are lower than 7%. This method is simple, rapid, accurate and precise.

Modeling Experimental Design for Photo-Fenton Degradation of Methomyl

Modeling experimental design was used to study the main effects and the interaction effects between operational parameters in the photocatalytic degradation of pesticide methomyl. The important parameters which affect the removal efficiency of methomyl such as concentration of Fe(NO3)3, concentration of H2O2, initial concentration of the pesticide and pH. The parameters were coded as x1, x2, x3 and x4, consecutively, and were investigated at two levels (–1 and +1). The effects of individual variables and their interaction effects for dependent variables, namely, photocatalytic degradation efficiency (%) were determined. From the statistical analysis, the most effective parameters in the photocatalytic degradation efficiency were initial concentrations of the methomyl and Fe(NO3)3. The interaction between initial concentration of the pesticide and Fe(NO3)3 was the most influencing interaction. The optimum conditions that were obtained for the photocatalytic degradation of methomyl were: minimum quantity of contaminant: 6 × 10–5 mol.L–1, maximum quantity of Fe(NO3)3: 5 × 10–4 mol.L-1, initial pH of the solution: 3 and maximum quantity H2O2: 10–2 mol.L–1.

Construction of Suppression Subtractive Hybridization Library for Testis of Male Tilapia Under the Stress of Methomyl

[Objectives]This study was conducted to construct forward and reserve libraries of suppression subtractive hybridization (SSH) in the testis of male tilapia under the stress of methomyl by using SSH technology.[Methods]Using male tilapia as the test animal,the forward and reserve libraries of SSH in the testis of tilapia under the stress of methomyl were constructed by using the SSH technology.[Results]45 expressed sequence tags (ESTs) were obtained,and 25 expressed sequence tags were successfully noted,including 13 forward libraries and 12 reverse libraries.The genes with confirmed functions were classified into five types.Genes related to catalytic activity and cell characteristics were up-regulated,while genes related to structural molecule's activity and biological process were down-regulated.The expression amount of integrin β1 was up-regulated,while serine/threonine protein kinase pim-3,Ca^2+-ATPase,Na^+-K^+-ATPase and ribosomal protein L22 were down-regulated.[Conclusions]The research results could lay a foundation for revealing the molecular mechanism of methomyl's reproductive toxicity to tilapia.

Testis of Male Tilapia Under Methomyl Stress: Transcriptome Changes and Signal Pathway Analysis

This study was conducted to find the differentially expressed genes and understand the transcriptome change characteristics in the testis of tilapia(Oreochromis niloticus) stressed by methomyl.The tilapia were exposed to 200 μg/L methomyl for 30 d,and then the testis samples were collected and used for the highthroughput sequencing.The results showed that 369 significant differentially expressed genes were obtained,including 160 significantly down-regulated genes,and209 significantly up-regulated genes.The enrichment of the differentially expressed genes in ECM-receptor interaction signaling pathway and MAPK signaling pathway was obvious.The adhesion of testis tissue cells was influenced by methomyl stress,which induced the expression of related gene in ECM-receptor interaction up-regulating,such as laminins,integrin α6 and integrin β1,in order to stabilize testis tissue structure.JNK,MAP3 K and MKK4 in the JNK pathway were significantly up-regulated,which enhanced transcription factor AP-1 to promote the expression of P53,Bax and other pro-apoptotic proteins.The expression of growth-related factors in the ERK pathway of MAPK signal pathway was influenced by methomyl stress.The apoptosis-related genes and pregnancy-related genes have significant differential expression under methomyl stress,and thereby,the proliferation of reproduction cells in the testis tissue may be affected.

Serum Antioxidant Enzymes SOD and CAT of Nile Tilapia(Oreochromis niloticus)in Response to Pesticide Methomyl and Recovery Pattern

Tilapia were exposed to sub-lethal concentrations of 0, 0.2, 2, 20 or 200 μg/L for 30 d, and then transferred to methomyl-free water for 18 d. CAT and SOD in tilapia serum were examined at 0, 6, 12, 18, 24 and 30 d after methomyl exposure and at 18 d after transferring to methomyl-free water. There were no significant changes in antioxidants activities in tilapia exposed to 0.2 μg/L. Significant increases in SOD, CAT were observed following methomyl exposure to 2, 20 or 200 μg/L, suggesting the presence of oxidative stress. Thus, the 0.2 μg/L methomyl might be considered the no observed adverse effect level. Recovery data showed that the effects produced by lower concentration of 20 μg/L were reversible but not at the higher concentration of 200 μg/L.

Isolation and Characterization of a Methomyl-Degrading Paracoccus sp.mdw-1

Methomyl,an extremely toxic pesticide,is widely used in agriculture.A strain named mdw-1 capable of degrading methomyl rapidly was successfully isolated from activated sludge in this study.It could utilize methomyl as the sole carbon or nitrogen source.The optimal temperature and medium pH for its growth and methomyl biodegradation were 30-C and 7.0,respectively.It was identified as a Paracoccus sp.according to its morphological features,physiological and biochemical characteristics,and phylogenetic analysis based on the sequence of 16S rDNA.Gas chromatography-mass spectrometry (GC-MS)analysis showed that methomyl could be completely transformed to S-methyl-N-hydroxythioacetamidate in 10 h of incubation with the isolate mdw-1.

高效液相色谱同时测定灭多威生产废水中的二甲基脲、灭多威肟和灭多威

采用高效液相色谱法,C18柱及二极检测器条件下,以V(甲醇)∶V(水[(0.1%醋酸铵)]=25∶75为流动相,检测波长210 nm,定量环20μL,流速1.0 mL/min,柱温40℃为色谱条件,同时测定灭多威生产废水中的二甲基脲、灭多威肟和灭多威。结果表明二甲基脲、灭多威肟、灭多威相关线性系数分别为0.999 87、0.999 94、0.999 88,平均添加回收率分别为99.98%、99.90%、100.01%,其标准偏差为0.12、0.16、0.092,相对标准偏差为0.49%、0.25%、0.36%。方法线性范围良好、灵敏快捷、准确可靠,适用于同时测定废水中二甲脲、灭多威肟和灭多威的含量。

二氯化二硫为原料合成硫双威绿色工艺研究

以灭多威、S_(2)Cl_(2)为原料合成硫双威,采用吡啶兼作碱化剂和溶剂,灭多威溶解在吡啶中,反应在液相体系中进行,利于传质、传热并提高反应效果。利用正交实验得到最佳工艺条件为:反应温度30℃,时间6 h,原料灭多威、S_(2)Cl_(2)和吡啶的摩尔比为1:0.7:6.5,醇洗剂用量为500 g甲醇/mol灭多威。灭多威的转化率达92.5%,硫双威收率达89.6%,产品为白色粉末状、颜色一致、粒度分布均匀,含量大于97.8%,热分解率低于2.4%。硫双威合成过程无废水产生,吡啶及副产物吡啶盐酸盐采用碱化处理、共沸蒸馏回收,甲醇采用精馏回收。该工艺路线绿色、环保,可推广到工业生产中。

HPLC-MS法测定茯苓中4种氨基甲酸酯类农药残留

目的:建立Qu ECh ERS样品前处理结合高效液相色谱-串联质谱法检测茯苓中氨基甲酸酯类农药的检测方法。方法:茯苓样品用含1%醋酸的乙腈溶液提取,盐析剂盐析后加入Mg SO4、PSA和C18进行萃取、净化,高效液相色谱-串联质谱仪检测,根据色谱峰的保留时间及特征离子对定性,基质匹配标准曲线外标法定量。结果:在2.0~100.0μg·L^(-1)时,各目标物线性关系良好,相关系数R^(2)>0.998;在0.015 mg·kg^(-1)、0.060 mg·kg^(-1)和0.600 mg·kg^(-1)添加水平下,回收率在77.3%~117.2%,相对标准偏差为0.2%~3.1%(n=6);方法检出限在0.60~1.00μg·kg^(-1)。结论:该方法准确度高、灵敏度好、高效快速,可用于茯苓中4种氨基甲酸酯类农药残留量的质量控制。

灭多威对藻-溞-鱼典型水生食物链生物的急性毒性研究

小球藻、大型溞和斑马鱼作为水生生态系统中第一、二和三营养级,是构成简单水生食物链的重要成员,参与了水生生态系统中的物质循环和能量流动。为了阐明灭多威对食物链上处于不同生态位的水生生物的毒性效应,采用半静态水质接触急性试验法研究了灭多威对小球藻、大型溞、斑马鱼的急性毒性。结果表明,灭多威对小球藻的96 h EC_(50)为6.76 mg/L,对大型溞的24、48、96 h LC_(50)分别为57.37、22.23、12.58μg/L,对斑马鱼的24、48、96 h LC_(50)分别为8.64、5.00、2.12 mg/L。根据农药毒性分级标准,农药灭多威在普通小球藻、大型溞、斑马鱼上分别表现为中毒性、极高毒性和高毒性,在自然环境下极易导致藻、溞、鱼急性中毒死亡。灭多威对小球藻、大型溞、斑马鱼的安全浓度分别为0.676 mg/L、1.26μg/L、0.212 mg/L,其对上述水生生物的毒性大小顺序为:溞类>鱼类>藻类。

碱解-Fenton氧化预处理灭多威生产废水

采用碱解—Fenton氧化工艺对灭多威生产废水进行处理,考察了液碱加入量、碱解温度和碱解催化剂对碱解处理效果的影响,分析了影响Fenton氧化效果的主要因素。实验结果表明:在液碱加入量5%(w)、碱解催化剂加入量5 g/L、碱解温度150℃、碱解时间5 h、双氧水加入量3%(w)、Fenton反应温度65℃、反应时间70 min的最佳工艺条件下,灭多威生产废水经碱解—Fenton氧化工艺处理后,COD由39347.5 mg/L降至5390.6 mg/L,去除率为86.3%,灭多威肟质量浓度由9021.2 mg/L降低至98.1 mg/L,去除率为98.9%,灭多威质量浓度由3354.5 mg/L降至未检出,BOD5/COD由0.02提高至0.34;采用碱解—Fenton氧化工艺处理1 t灭多威生产废水的药剂成本为103.01元。

高效液相色谱—质谱联用法测定苹果中9种氨基甲酸酯及其代谢物农药残留量

本文研究了甲奈威、灭多威、异丙威、抗蚜威、克百威(3-羟基克百威)、涕灭威(涕灭威砜、涕灭威亚砜)在苹果上的残留量,建立了使用液质联用仪同时检测的方法,样品提取液中加入无水MgSO_(4),NaCl,柠檬酸钠后振摇离心,上清液中加入无水MgSO_(4)和PSA,继续振摇离心,上清液过膜上机检测,大大降低了干扰,提高了检测的灵敏度。该方法操作简单、快速、灵敏度高。

高效液相色谱柱后衍生法测定谷物中3种氨基甲酸酯类农药残留

采用高效液相色谱柱后衍生法,即将谷物样品粉碎后,经乙腈提取、氮吹、甲醇复溶、固相萃取柱净化、甲醇-二氯甲烷溶液洗脱、氮吹、甲醇定容后,经带有柱后衍生系统和荧光检测器的高效液相色谱仪检测,对谷物中灭多威、涕灭威、克百威3种氨基甲酸酯类农药的残留量进行测定外标法定量。该方法的灭多威、涕灭威、克百威检出限均为0.008 mg/kg;相对标准偏差(RSD)均小于7.5%,加标回收率为80.6%~109.0%,3种农药混合标准曲线最佳线性范围0.01~2.0μg/mL,线性相关系数(R)均大于0.9995。结果表明,该方法具有良好的线性关系,准确性和精密度高,操作简单,适用于谷物中涕灭威、灭多威、克百威农药残留量的同时检测。

乙醛肟合成技术进展及综合市场分析

乙醛肟是除氧效果优良的新型除氧剂,也是一种重要的有机合成和分析试剂。在农药行业乙醛肟可以制成甲硫基乙醛肟,进一步可合成农药灭多威和硫双威。灭多威是使用最广泛的杀虫剂品种之一,其用量居世界杀虫剂品种前十位,近年其使用量有快速增长的趋势。硫双威又名硫双灭多威,是灭多威低毒化产品。综述了乙醛肟的各种生产路线,其中重点介绍硫酸羟胺法的工艺进展。同时对乙醛肟的国内生产现状、市场需求及发展趋势做了分析,并对我国乙醛肟的生产和发展提出了建议。

高效液相色谱-串联质谱法测定马铃薯中灭多威残留量不确定度评定

为提高马铃薯食品安全检测结果的准确性,利用高效液相色谱-串联质谱法对马铃薯中灭多威进行测定,分析具体试验过程,建立数学模型,确定各测量不确定度分量并进行比较。当马铃薯中灭多威残留量1.3μg/kg时,其扩展不确定度0.84μg/kg(k=2)。结果表明,在各测量不确定度分量中,仪器本身、标准曲线绘制、试验方法重复性所带来的不确定度占主要因素。

农药灭多威和辛硫磷对罗非鱼的联合毒性研究

采用更新式静态急性试验法,研究了灭多威和辛硫磷对罗非鱼的单一及联合毒性。结果显示,灭多威和辛硫磷对罗非鱼的24、48、96 h-LC50分别为1.25、0.75、0.43 mg·L-1和13.30、6.98、4.58 mg·L-1,安全浓度分别为0.043 mg·L-1和0.458 mg·L-1。按照农药毒性分级标准,灭多威对罗非鱼是极高毒农药,辛硫磷对罗非鱼是高毒农药。联合毒性试验结果显示:灭多威和辛硫磷在24、48、96h的相加指数分别为0.24、0.26、0.06,相加指数均大于零;SOD活性研究显示,灭多威、辛硫磷以及灭多威+辛硫磷对SOD活性有显著抑制效应,且抑制作用随染毒浓度的增加而增强,同时,灭多威和辛硫磷联合染毒对罗非鱼肝脏SOD活性的抑制效应较相同条件下单一灭多威或辛硫磷染毒时强;表明灭多威和辛硫磷对罗非鱼的联合毒性表现为协同作用,它们的共存会对鱼类产生更强的毒性作用。在环境评价中,决不能简单地将各单一污染物毒性相加来判断其综合毒性。

基于太赫兹时域光谱技术的农药残留检测方法

太赫兹时域光谱（THz-TDS）技术是近年来涌现出来的崭新的光谱测量新技术．本研究提出了一种基于THz-TDS技术农药残留检测方法，并以灭多威和乙氧氟草醚两种农药作为实验介质证明此方法的可行性．应用太赫兹时域光谱系统测得了这两种农药的时域光谱信号，利用基于菲涅尔公式的数据处理模型得到了它们在THz波段的折射率谱和吸收系数谱．从实验结果可以看出两种农药在0．2—2．0THz范围内存在明显的特征吸收峰，且差别很大．经分析认为这些吸收峰是由分子的集体振动模式以及分子间相互作用引起，它们是农药分子的指纹吸收光谱，可以应用于分子识别中．本研究证明了THz—TDS技术应用于农药残留检测的可行性，表明其在农药残留检测中具有潜在的应用价值．

灭多威的超声降解研究

研究了灭多威模拟废水在超声作用下的降解反应动力学、降解产物、降解途径、以及影响降解速率的因素等问题．结果表明，灭多威经超声作用３５ｍｉｎ，可被完全转换为无机物，其降解过程为假一级反应；浓度增加时，降解减慢； Ｆｅ２＋和 Ｈ２Ｏ２对降解有促进作用，且 Ｆｅ２＋促进作用比 Ｈ２Ｏ２的大；采用不同气体饱和溶液时，降解率的大小有下列顺序：Ａｒ＞Ｏ２＞Ａｉｒ＞Ｎ２．红外光谱表明降解产物为 ＳＯ２４－、 ＮＯ３和 ＣＯ２．