Sol-gel entrapment of monoclonal anti-atrazine antibodies

We report the successful doping of a sol-gel matrix with an antibody, retaining its ability to bind free antigen from an aqueous solution. The particular system described is monoclonal anti-atrazine mouse antibody which was entrapped in SiO₂ sol-gel matrices, prepared from tetramethoxysilane by several methods. Atrazine was selected as a model compound for this study, within the framework of the development of immunochemical-based methods for monitoring pesticide residues and other organo-synthetic environmental contaminants. Nanogram quantities of atrazine were applied on SiO₂ sol-gel columns doped with this antibody, and the amount of eluted antigen was determined by Enzyme Linked ImmunoSorbent Assay (ELISA). Under appropriate sol-gel-forming conditions, high amounts of atrazine were bound to the sol-gels, ranging between 60% and 91% of the amount applied to the column. The combination of the properties of the sol-gel matrix (e.g., stability, inertness, high porosity, high surface area and optical clarity), together with the selectivity and sensitivity of the antibodies, enable extension of this feasibility study to development of a novel group of immunosensors which could be used for purification, concentration and monitoring of a variety of residues from different sources.Contribution from the Agricultural Research Organization (ARO), Bet Dagan, Israel. No., 1697-E, 1995 series.     

Determination of atrazine, desethyl atrazine and desisopropyl atrazine in environmental water samples using hollow fiber-protected liquid-phase microextraction and high performance liquid chromatography

A new method based on hollow fiber-protected liquid-phase microextraction (LPME) was developed for the simultaneous determination of atrazine, desethyl atrazine and desisopropyl atrazine in environmental water samples. In LPME, analytes were extracted into 1-octanol immobilized in the micropores of a poly(vinylidene fluoride) porous hollow fiber membrane, and back extracted into the acceptor (4 M HCl) filled in the lumen of the hollow fiber. After LPME, the analytes trapped in the acceptor were analyzed with high-performance liquid chromatography after neutralization. The effect of extraction factors such as sample pH, acceptor pH, salinity, extraction time, stirring rate, and humic acid were studied. Under the optimized conditions, the limits of detection and relative standard deviations were respectively in the range of 0.5–1.0 μg L⁻¹ and 3.9–4.7% (n = 5). The proposed method was applied to determine atrazine, desethyl atrazine and desisopropyl atrazine in wastewater and groundwater samples. The three analytes were below the limits of detection, but good relative spiked recoveries over 90.1 ± 5.9% at 5 μg L⁻¹ spiked level were obtained.     

莠去津在填充土柱中的运移

用土柱实验模拟莠去津在土壤中的运移、实验结果表明相当浓度的莠去津被淋溶到土柱的底部，说明莠去津对地下水存在很大威胁、应用CXTFIT的平衡与非平衡模型模拟莠去津在土柱中的运移，模拟结果表明CXTFIT的非平衡模型能很好地模拟莠去津的穿透曲线．由CXTFIT率定得到的莠去津在土柱实验中的吸附和降解参数和从批次实验得到的吸附和降解参数有较好的一致性．     

Spectrophotometric method for determination of atrazine and its application to commercial formulations and real samples

A simple sensitive spectrophotometric method has been developed for the determination of atrazine in herbicide formulations and real samples. The method was based on the reaction of atrazine with pyridine to form a quaternary halide which in the presence of alkali forms a carbinol base. The heterocyclic ring of the carbinol base breaks and forms the glutaconic dialdehyde. The glutaconic dialdehyde group was coupled with sulfanilic acid to form a yellow coloured product having λ _max 450 nm or coupled with aniline to form a orange red coloured product having λ _max 480 nm. The Beer's law was obeyed over the range from 0.1 to 25 µg mL^?1 and molar absorptivity 1.5 × 10⁴ L mol^?1 cm^?1 for sulfanilic acid, and from 0.08 to 12 µg mL^?1 and molar absorptivity 1.3 × 10⁴ L mol^?1 cm^?1 for aniline were observed. The reaction conditions and other analytical parameters were optimised. The proposed method has been successfully applied for the analysis of commercial formulations and real samples.     

二氧化锆微球表面键合磺化交联聚苯乙烯固相萃取填料的制备及应用

以聚合诱导胶体凝聚法(PICA)制备二氧化锆微球,用钛酸酯偶联剂对其进行表面改性,使其接枝上碳碳双键基团。在溶液体系中,该双键与单体苯乙烯和二乙烯苯在自由基引发下交联聚合,形成的聚合物包覆在二氧化锆微球表面。再通过磺化方法将磺酸基离子连接到苯环上,得到阳离子交换固相萃取填料。通过红外光谱、扫描电镜/X射线能谱等手段对其进行了表征。将装填得到的固相萃取柱与高效液相色谱联用,测定了水中的甲基磺草酮、阿特拉津和乙草胺。3种化合物的色谱峰面积与质量浓度呈良好的线性关系,相关系数(r²)均大于0.99;甲基磺草酮、阿特拉津和乙草胺的检出限分别为5.41、6.72和13.4 μg/L。结果表明,制得的聚合物包覆二氧化锆微球的粒径为6~8 μm,用该填料制成的固相萃取小柱对3种目标物的吸附率高。     

TRANSFER OF THE ATRAZINE-RESISTANT GENE OF BLACK NIGHTSHADE TO SOYBEAN CHLOROPLAST GENOME AND ITS EXPRESSION IN TRANSGENIC PLANTS

The atrazine-resistant psbA gene of black nightshade was transferred to the chloroplast genome of atrazine-susceptible soybean by means of ovary microinjection during the stage of zygote. The identification was carried out by using the methods of spraying the leaves directly with atrazine solution, examining the change of leaf fluorescence kinetics under a brighter light induction, molecular hybridization, etc. The experimental results show that the transgenic soybean plants do have been obtained for the first time.     

Synthesis of a molecularly imprinted polymer on mSiO2@Fe3O4 for the selective adsorption of atrazine

Atrazine contamination of water is of considerable concern because of the potential hazard to human health. In this study, a magnetic molecularly imprinted polymer for atrazine was prepared by the surface‐imprinting technique using Fe₃O₄ as the core, mesoporous silica as the carrier, atrazine as the template, and itaconic acid as the functional monomer. The magnetic molecularly imprinted polymer was characterized by Fourier‐transform infrared spectroscopy, scanning electron microscopy, X‐ray diffraction, and vibration‐sample magnetometry. The binding properties of the magnetic molecularly imprinted polymer toward atrazine were investigated by adsorption isotherms, kinetics, and competitive adsorption. It was found that the adsorption equilibrium was achieved within 2 h, the maximum adsorption capacity of atrazine was 8.8 μmol/g, and the adsorption process could be well described by the Langmuir isotherm model and pseudo‐second‐order kinetic model. The magnetic molecularly imprinted polymer exhibited good adsorption selectivity for atrazine with respect to structural analogues, such as cyanazine, simetryne, and prometryn. The reusability of the magnetic molecularly imprinted polymer was demonstrated for at least five repeated cycles without a significant decrease in adsorption capacity. These results suggested that the magnetic molecularly imprinted polymer could be used as an efficient material for the selective adsorption and removal of atrazine from water samples.     

对土壤及玉米植株中均三氮苯类除草剂的残留分析

土壤或玉米植株样品用Ｖ（甲醇）∶Ｖ（乙腈）＝１∶１提取,提取液用石油醚净化后,浓缩液过Ｃ１８小柱净化,最后用Ｎｏｖａ－ＰａｋＣ１８柱进行ＨＰＬＣ分析。回收率：氰草津为８２．４％～９９．８％,莠去津为８５．６％～１０２．３％,西草净为８９．１％～１０８．４％。     

高效液相色谱法同时测定水体中马拉硫磷和阿特拉津

通过条件实验, 建立了以V(甲醇)∶V(水)=7∶3为流动相, 最佳测定波长为220 nm的高效液相色谱同 时测定阿特拉津和马拉硫磷的方法. 方法线性范围: 马拉硫磷0.003 66~1.83 μmol/L, 阿特拉津0.121~60.3 μmol/L, 线性相关系数r≥0.9994, 相对标准偏差小于10%. 方法检出限分别为马拉硫磷0.003 66 μmol/L, 阿特拉津0.121 μmol/L.     

Monoclonal Antibody-Based Immunolocalization of Bound Triazine Residues in Two Aquatic Macrophytes (Elodea Canadensis and Myriophyllum Spicatum)

Abstract

Immunohistochemical localization offers a fast and reliable method of obtaining information about the distribution of bound pesticide residues in plants. In the present study aquatic macrophytes (Elodea canadensis, Myriophyllum spicatum) were grown in laboratory model ecosystems spiked with 50 μg/l atrazine. To label cryosections, monoclonal antibodies from cell culture supernatants and ascites fluid with differing specificities for s-triazines were used in combination with the fluorescent dye Phycoerythrin and biotin-streptavidin amplification. The best results were observed with antibodies gained from mice immunized with an ametryn sulfoxide-BSA conjugate, regardless of the method employed for antibody production. The consequences with respect to herbicide metabolism and binding are discussed.