MICROWAVE SYNTHESIS OF TRICHLORFON AND ITS ANALOGUES

The synthesis of dialkyl-(2,2,2-trichloro-1-Hydroxyethyl) phosphonates using dialkyl hydrogen phosphite and chloral hydrate under solvent-free condition by microwave irradiation is reported. The products were chrachetrized using ¹ H NMR, ¹³ C NMR, and ³¹ P NMR spectroscopy.     

乙酰胆碱酯酶/Nafion/普鲁士蓝修饰玻碳电极的制备及其在有机农药检测中的应用

制备了乙酰胆碱酯酶/Nafion/普鲁士蓝修饰的玻碳电极,测试了该修饰电极检测有机农药西维因(carbaryl)和敌百虫(trichlorfon)的性能指标。 利用原子力显微镜和电化学技术研究了电极的构造及其对于有机农药检测性能指标的影响。 结果表明,乙酰胆碱酯酶均匀地分散到Nafion/普鲁士蓝修饰的玻碳电极上。 在最优的实验条件下,构筑的修饰电极检测西维因和敌百虫的线性范围分别为0.01~0.5 μmol/L及2.0~10.0 μmol/L和0.02~1.0 μmol/L及2.0~8.0 μmol/L,检出限分别为5.0和10.0 nmol/L。 并对模拟的实际样品进行了检测,发现该方法有较高的检测灵敏度、较好的重复性和抗干扰性。     

基于修饰石墨烯/纳米金复合膜固定乙酰胆碱酯酶的敌百虫传感器

结合氨基功能化离子液体修饰石墨烯(IL-GR)、纳米金(Au)等纳米材料的独特性质,以壳聚糖(CHIT)为交联剂,首先在玻碳电极表面固定IL-GR,然后吸附胶体金制得Au/IL-GR-CHIT复合膜,最后固定乙酰胆碱酯酶(AChE)制得新型有机磷检测酶传感器(AChE/Au/IL-GR-CHIT/GCE),并用于白菜样品中敌百虫农药的测定。采用透射电镜(TEM)对纳米材料进行了表征,循环伏安法(CV)和差示脉冲伏安法(DPV)研究了传感器的电化学性质。纳米复合物不仅为保持AChE的生物活性提供了适宜的微环境,并且对传感器性能的改善显示出强大的协同效应。在优化实验条件下,抑制率(A)与敌百虫浓度的负对数在2.0×10-10~1.0×10-6mol/L范围内呈良好的线性关系,检出限(S/N=3)为2.1×10-12mol/L。用于蔬菜中敌百虫含量的测定,回收率为97.5%~107.2%。     

Preparation and Characterization of a Molecularly Imprinted Polymer for Selective Recognition of Trichlorfon and Monocrotophos

In this study, a molecularly imprinted polymer (MIP) that can selectively recognize both the trichlorfon and the structurally related compound of monocrotophos pesticides was prepared using mixtures of trichlorfon and monocrotophos as template molecules, methacrylic acid (MAA) as a functional monomer, and ethylene glycol dimethacrylate as a cross-linker. The polymerization conditions had an important influence on the adsorption ability of imprinted polymer. When the ratio of trichlorfon and monocrotophos was 1.5:1 (mol/mol), the MIP had high adsorption capacity. The prepared polymers were characterized by Fourier transform infrared spectroscopy and static and kinetic adsorption experiments. The results indicated that the P = O groups of trichlorfon and monocrotophos reacted with the -OH groups of MAA during the synthesis of MIP. The imprinted polymer exhibited good recognition ability and higher selectivity toward trichlorfon and monocrotophos than the structurally related pesticide compounds of acephate and methamidophos, and offered fast kinetics for solid phase by the MIP adsorption of trichlorfon and monocrotophos from liquid phase.     

玻璃毛细管电泳芯片安培法对敌百虫的检测

采用三电极体系的芯片毛细管电泳安培柱端检测器检测具有还原性的联苯胺,由于敌百虫能够催化过硼酸钠氧化联苯胺的反应,且反应后联苯胺浓度的减少量与敌百虫的加入浓度有线性关系,据此建立了间接检测敌百虫的芯片毛细管电泳法。考察了联苯胺的浓度、缓冲液的pH值、进样时间、分离电压、检测电位等对分离效率和检测信号的影响。在优化实验条件下,敌百虫的线性范围为20~400μg/L,相关系数为0.991 3,检出限为10μg/L。应用该法测定大白菜样品中敌百虫的残留量,结果满意。     

气相色谱-质谱法研究敌百虫在气相色谱分析过程中产生的分解产物

利用气相色谱-质谱联用技术对敌百虫在气相色谱分析过程中产生的分解产物进行定性研究。通过质谱解析鉴定出敌百虫的分解产物有三氯乙醛、磷酸二甲酯和敌敌畏。研究了气相色谱条件如进样口温度、柱温升温速率、进样方式对敌百虫分解产物的影响。实验结果表明:这3种因素对敌百虫的稳定性均有不同程度的影响,其中进样口温度是导致敌百虫分解的主要因素,进样口温度越高,敌百虫的分解量就越大。