农药残留速测技术方法与进展

为了确保农产品的安全性,对蔬菜等农产品进行农药残留快速检测十分必要.目前农药残留快速检测有酶学法和化学检测法.由于这两种速测方法只能定性,不可定量,并且影响检测结果的干扰因素较多.为此,以ELISA为基础建立的农药残留酶联免疫检测法,以其专化性强、灵敏度高,将逐渐成为有发展前景的定性与定量相结合的农药残留速测技术.     

酶联免疫吸附技术分析及其在食品安全检测中的应用

酶联免疫吸附技术是一种对免疫系统的分析方法,这种方法操作简单、针对性强、快速有效,常用在对食品的安全检测中。文章介绍了酶联免疫吸附技术的工作原理和具体应用类型,并分析了酶联免疫吸附技术在食品安全检测中的应用现状和发展前景。     

酶联免疫吸附法测定猪肉中的“瘦肉精”

本文介绍了酶联免疫吸附法测定猪肉中的盐酸克伦特罗的方法。利用盐酸克伦特罗试剂盒,对猪肉组织中的盐酸克伦特罗残留经抽提、竞争后,用酶标仪进行检测分析。此法较适用于现场检验,检测速度快、灵敏度高,是保证肉品卫生安全的较好监控方法。     

酶联免疫吸附法测定猪肉中的"瘦肉精"

本文介绍了酶联免疫吸附法测定猪肉中的盐酸克伦特罗的方法。利用盐酸克伦特罗试剂盒，对猪肉组织中的盐酸克伦特罗残留经抽提、竞争后，用酶标仪进行检测分析。此法较适用于现场检验，检测速度快、灵敏度高，是保证肉品卫生安全的较好监控方法。     

常用蔬菜农药残留速测方法的应用效果研究

利用气相色谱定量检测的验证方法,对目前常用的7种蔬菜农药残留速测方法的灵敏度、正确率、稳定度等指标进行综合评价,筛选出RP-410型农药残留快速测定仪和新灵二种相对较好的速测方法。综合使用成本、操作难易等因素,提出了两者不同推广适宜点。     

基于二聚人工抗原ELISA检测多残留β_2-受体激动剂

目的:基于二聚人工抗原研制具备多识别特性的广谱抗体，结合酶联免疫吸附技术，为β_2-受体激动剂快速检测提供技术支持。方法:克伦特罗和莱克多巴胺与载体蛋白经重氮化反应形成二聚人工抗原，优化实验条件，制备单克隆抗体，运用酶联免疫吸附技术同时检测苯酚型和苯胺型β_2-受体激动剂。结果:在最佳条件下，克伦特罗、莱克多巴胺、克伦特罗和莱克多巴胺的IC_(50)值分别为0.75 ng/mL、0.77 ng/mL和0.77 ng/mL。该方法检测的回收率为78.00%～117.88%。检测结果与LC-MS/MS具有良好的一致性(R²>95%)。结论:本研究建立的一种简单、快速、高灵敏的测定方法，可用于快速检测猪尿中β_2-受体激动剂药物残留。     

果蔬农药残留快速检测技术的现状及展望

本文概述了国内外水果蔬菜农药残留快速检测技术的研究进展和应用状况，探讨了近年发展起来的一些农药残留速测新技术。通过各种方法的对比分析总结出目前农药残留分析研究的发展方向，这些将给果蔬农药残留分析带来很大的进步，并使残留分析逐步趋于陕捷、精确、标准。     

酶联免疫吸附测定技术在食品安全检测中的应用

酶是一种具有催化作用的蛋白质，具有高效性和专一性等特点。近年来，将酶制剂应用于食品分析检测中，显著提高了检测效率。酶法检测以其发展迅速、应用广泛等特点在众多方法中脱颖而出。其中最重要的是酶标免疫反应，可应用于食品安全检测的诸多方面。而在这其中最有前景，应用最广的是酶联免疫吸附测定技术。     

ELISA法测定尿液中鬼臼毒素的含量

本文建立了一种利用IC-ELISA法测定尿液中的鬼臼毒素的方法。尿液样经离心沉淀,采用间接竞争酶联免疫吸附法(IC-ELISA)测定。鬼臼毒素的添加浓度在0.5 mg/L-10 mg/L时,回收率范围为78.3%-99.3%,相对标准偏差(RSD)在4.3%-11.5%之间。方法最低检测浓度为0.012μg/mL,检测范围为0.025-19.59μg/mL。方法的准确度和精密度符合残留分析要求。方法操作简捷,结果可靠稳定,比仪器方法检测成本低。     

弓形虫H11基因克隆表达及其临床应用研究

提取弓形虫速殖子总RNA,RT-PCR扩增H11基因片段并构建重组表达载体,诱导GST-H11融合蛋白大量表达,并经亲和层析柱纯化,通过免疫印迹和酶联免疫吸附两种方法检测弓形虫特异性兔抗血清和人阳性血清,结果显示GST-H11融合蛋白检测两者血清敏感性和特异性均较高,提示H11融合蛋白可望用作诊断性抗原应用于弓形虫患者临床检测。     

β-Galactosidase-based colorimetric paper sensor for determination of heavy metals

We demonstrate a novel approach for rapid, selective, and sensitive detection of heavy metals using a solid-phase bioactive lab-on-paper sensor that is inkjet printed with sol-gel entrapped reagents to allow colorimetric visualization of the enzymatic activity of β-galactosidase (B-GAL). The bioactive paper assay is able to detect a range of heavy metals, either alone or as mixtures, in as little as 10 min, with detection limits as follows: Hg(II) = 0.001 ppm; Ag(I) = 0.002 ppm, Cu(II) = 0.020 ppm; Cd(II) = 0.020 ppm; Pb(II) = 0.140 ppm; Cr(VI) = 0.150 ppm; Ni(II) = 0.230 ppm. The paper-based assay was immune to interferences from nontoxic metal ions such as Na(+) or K(+), could be used to detect heavy metals that were spiked into tap water or lake water, and provided quantitative data that was in agreement with values obtained by atomic absorption. With the incorporation of standard chromogenic metal sensing reagents into a multiplexed bioactive paper sensor, it was possible to identify specific metals in mixtures, albeit with much lower detection limits than were obtained with the enzymatic assay. The paper-based sensor should be valuable for rapid, on-site screening of trace levels of heavy metals in resource limited areas and developing countries.     

Characteristics of air pollution control residues of MSW incineration plant in Shanghai

A unique type of waste--air pollution control (APC) residues--has received increasing attention in China since the first large-scale incinerator, Shanghai Yuqiao municipal solid waste (MSW) incineration plant, was installed in the country in 2002. The APC residues of this particular plant are similar to other residues that will be produced in other incineration plants under construction in China. This work examines for the first time the benchmark contaminants of APC residues from the Yuqiao Plant, with reference to soluble salts, heavy metals and dioxins. Experimental findings reveal that the residues contained a marked amount of soluble salts, of up to 17.4-21.9% (mostly chlorides), 0.98-1.5 ngTEQ/gash of dioxins and various heavy metals. Lead is of particular concern, and requires stabilization before disposal. Heavy metal speciation schemes were implemented herein to determine the leaching characteristics. The correlation between the amounts of soluble salts or chemical speciation of the heavy metals and the leaching toxicity of these heavy metals in the residues is considered.     

Heavy metal leaching from aerobic and anaerobic landfill bioreactors of co-disposed municipal solid waste incineration bottom ash and shredded low-organic residues

In this study, heavy metal leaching from aerobic and anaerobic landfill bioreactor test cells for co-disposed municipal solid waste incineration (MSWI) bottom ash and shredded low-organic residues has been investigated. Test cells were operated for 1 year. Heavy metals which were comparatively higher in leachate of aerobic cell were copper (Cu), lead (Pb), boron (B), zinc (Zn), manganese (Mn) and iron (Fe), and those apparently lower were aluminum (Al), arsenic (As), molybdenum (Mo), and vanadium (V). However, no significant release of heavy metals under aerobic conditions was observed compared to anaerobic and control cells. Furthermore, there was no meaningful correlation between oxidation-reduction potential (ORP) and heavy metal concentrations in the leachates although some researchers speculate that aeration may result in excessive heavy metal leaching. No meaningful correlation between dissolved organic carbon (DOC) and leaching of Cu and Pb was another interesting observation. The only heavy metal that exceeded the state discharge limits (10mg/l, to be enforced after April 2005) in the aerobic cell leachate samples was boron and there was no correlation between boron leaching and ORP. Higher B levels in aerobic cell should be due to comparatively lower pH values in this cell. However, it is anticipated that this slightly increased concentrations of B (maximum 25mg/l) will not create a risk for bioreactor operation; rather it should be beneficial for long-term stability of the landfill through faster washout. It was concluded that aerobization of landfills of heavy metal rich MSWI bottom ash and shredded residues is possible with no dramatic increase in heavy metals in the leachate.     

Factorial experimental design for recovering heavy metals from sludge with ion-exchange resin

Wastewaters containing heavy metals are usually treated by chemical precipitation method in Taiwan. This method can remove heavy metals form wastewaters efficiently, but the resultant heavy metal sludge is classified as hazardous solid waste and becomes another environmental problem. If we can remove heavy metals from sludge, it becomes non-hazardous waste and the treatment cost can be greatly reduced. This study aims at using ion-exchange resin to remove heavy metals such as copper, zinc, cadmium, and chromium from sludge generated by a PCB manufacturing plant. Factorial experimental design methodology was used to study the heavy metal removal efficiency. The total metal concentrations in the sludge, resin, and solution phases were measured respectively after 30 min reaction with varying leaching agents (citric acid and nitric acid); ion-exchange resins (Amberlite IRC-718 and IR-120), and temperatures (50 and 70 degrees C). The experimental results and statistical analysis show that a stronger leaching acid and a higher temperature both favor lower heavy metal residues in the sludge. Two-factors and even three-factor interaction effects on the heavy metal sorption in the resin phase are not negligible. The ion-exchange resin plays an important role in the sludge extraction or metal recovery. Empirical regression models were also obtained and used to predict the heavy metal profiles with satisfactory results.     

Simultaneous sorption and desorption of Cd, Cr, Cu, Ni, Pb, and Zn in acid soils II. Soil ranking and influence of soil characteristics

In Part I of this paper we reported, for each of 11 acid soils, the rankings of six metals according to their sorption from solutions containing all six, and according to their retention under desorption conditions. Here, we analyse the same data from a different perspective: for each metal, we rank the soils by their capacities to sorb and retain it as reflected by soil/solution distribution coefficients K(d100) measured using starting solutions containing 100mgL(-1) of each metal. We also ranked the soils for overall heavy metal sorption and retention capacities using Kaplan's compound measure K(dSigma), and we investigated the influence of soil characteristics on K(d100) and K(dSigma100) values. Overall capacity for sorption of heavy metals was positively related to HOM, kaolinite and Fe oxides contents, and negatively related to CEC and to vermiculite and haematite contents. Overall capacity for retention of heavy metals was positively related to HOM and kaolinite contents, and negatively related to CEC and vermiculite content. The good correlation between K(dSigma100)(sorption) and the first component extracted in a principal components analysis of K(d100)(sorption) values, and between K(dSigma100)(retention) and the first component extracted in a principal components analysis of K(d100)(retention) values, supports the adequacy of K(dSigma) as a measure of the overall capacity of a soil to sorb or retain heavy metals.     

Thermal treatment of harzardous waste for heavy metal recovery

In this study, a new method for recovering heavy metals from hazardous waste is introduced. The process is characterized by a separation of heavy metals and residues during the thermal treatment under a sub-stoichiometric atmosphere in a rotary kiln. After leaving the rotary kiln the separated heavy metals are precipitated in a hot gas ceramic filter. Using this technology, hazardous materials, both liquids and pasty hazardous waste containing heavy metals, can be treated and a product with a quasi-raw material condition can be formed. In contrast to current methods,the harmful substances should not be immobilized and disposed. In fact, a saleable product highly concentrated with heavy metals should be formed. During preliminary investigations with a solution containing sodium chromate tetrahydrate, the process was tested in a pilot plant. Here,the separation of chromium could be demonstrated with leaching tests and characterization of the filter dust. Analysis concerning the disposability of the residues had not been carried out because only the process and the characteristic of the filter dust were in the centre of attention.     

杭州下沙河道底泥重金属检测及污染分析

检测了杭州下沙河网区18条河道表层底泥重金属Cu、Zn、Pb、Cd、Ni的含量,分析了研究区域内的重金属污染情况,并用潜在生态危害指数法对河道底泥重金属污染情况进行评价,通过聚类分析法分析重金属的空间分布特征.结果表明,Cd污染最严重,超标率为94.44%,平均超标倍数为16.50,Cd的平均潜在生态风险为很高风险,Cu、Zn、Pb、Ni的平均潜在生态风险为低风险,重金属平均综合潜在生态风险属于高风险.重金属聚类分析结果显示Cd、Ni、Pb三种元素相关性显著,应受同一污染源因素影响;采样点聚类分析结果显示下沙河网河道底泥重金属污染分布较为均匀.     

Recent Advances of Electrospun Nanofibrous Membranes in the Development of Chemosensors for Heavy Metal Detection

It is critical to detect and analyze the heavy metal pollutions in environments and foods. Chemosensors have been widely investigated for fast detection of analytes such as heavy metals due to their unique advantages. In order to improve the detection sensitivity of chemosensors, recently electrospun nanofibrous membranes (ENMs) have been explored for the immobilization of chemosensors or receptors due to their high surface‐to‐volume ratio, high porosity, easiness of fabrication and functionalization, controllability of nanofiber properties, low cost, easy detection, no obvious pollution to the detection solution, and easy post‐treatment after the detection process. The purpose of this review is to summarize and guide the development and application of ENMs in the field of chemosensors for the detection of analytes, especially heavy metals. First, heavy metals, chemosensors, and four types of preparation methods for ENM‐immobilized chemosensors/receptors are briefly introduced. And then, ENM‐immobilized chemosensors/receptors and their application progresses for optical, electro, and mass detections of heavy metals are reviewed according to the four types of preparation methods. Finally, the application of ENM‐immobilized chemosensors/receptors is summarized and an outlook is provided. The review will provide an instruction to the research and development of ENM‐immobilized chemosensors/receptors for the detection of analytes.     

Heavy metal stabilization in municipal solid waste incineration flyash using heavy metal chelating agents

Heavy metal chemical stabilization with synthesized heavy metal chelating agent was assessed for flyash from municipal solid waste incinerator. Flyash can contain heavy metals (e.g. Pb, Cd) which can leach. A new kind of heavy metal chelating agent showed more attractive competition than inorganic chemicals in stabilizing flyash. The synthesizing method of this kind of heavy metal chelating agent was explained in this paper, and the technology process and treatment efficiency of the chelating agent in treating flyash were experimentally studied, which was compared with the results of inorganic chemical agents such as sodium sulfide and lime. The heavy metals in flyash were stabilized more effectively by using heavy metal chelating agents than by using sodium sulfide and lime, furthermore, the stabilized products using the chelating agents can meet the landfill disposal controlling standards for heavy metal waste. pH-dependent leaching experiment showed the stabilized flyash by treatment with heavy metal chelating agent could keep long-term stabilization within a broad range of pH value. Thus, the risk of secondary pollution for the stabilized products was reduced dramatically when the environment condition changes during its disposal period.     

Highly ordered three-dimensional macroporous carbon spheres for determination of heavy metal ions

An effective voltammetric method for detection of trace heavy metal ions using chemically modified highly ordered three dimensional macroporous carbon spheres electrode surfaces is described. The highly ordered three dimensional macroporous carbon spheres were prepared by carbonization of glucose in silica crystal bead template, followed by removal of the template. The highly ordered three dimensional macroporous carbon spheres were covalently modified by cysteine, an amino acid with high affinities towards some heavy metals. The materials were characterized by physical adsorption of nitrogen, scanning electron microscopy, and transmission electron microscopy techniques. While the Fourier-transform infrared spectroscopy was used to characterize the functional groups on the surface of carbon spheres. High sensitivity was exhibited when this material was used in electrochemical detection (square wave anodic stripping voltammetry) of heavy metal ions due to the porous structure. And the potential application for simultaneous detection of heavy metal ions was also investigated.