共查询到19条相似文献,搜索用时 125 毫秒
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食品中的重金属污染及其检测技术 总被引:2,自引:0,他引:2
简述目前食品中重金属的污染情况,简要介绍国内外对食品中重金属的限量规定,着重介绍食品中重金属污染物的检测技术并讨论其未来的发展趋势。 相似文献
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关于食品和血液中的铅超标问题报道较多,尤其由于铅污染导致居民中毒事件屡屡发生,针对重金属污染事故频发的情况,环境保护部也组织编制了重金属污染防治规划,统筹规划重金属污染治理。判定铅中毒最常用和最有效的方法是检测血铅,血铅水平能准确的反应出机体近期铅中毒程度。本文主要对铅在检测中需要注意的事项及卫生部有关标准中的一些问题进行探讨。 相似文献
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采用X荧光光谱法测定了塑料、金属、陶瓷等多类玩具饰品表面中的重金属Cr、Cd、Pb、Hg含量。仪器预热初始化后,对不同大小,不同形状,不同属性的样品无需做任何的预处理,直接无损测定其表面重金属的含量。单个样品测定时间为2~3分钟,可连续不间断测定,检测限低,可达2mg/kg,相对标准偏差低于4.6%。所用仪器为国产仪器,仪器成本及运行和维护成本低,应用于现场实时分析,便于推广。该法具有分析速度快、操作简单、对样品无任何损坏等特点,用于玩具饰品中重金属Cr、Cd、Pb、Hg含量的测定,简单,实用。 相似文献
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Morphostructural and immunohistochemical study on the role of metallothionein in the detoxification of heavy metals in Apis mellifera L., 1758 下载免费PDF全文
Antonio Salvaggio Roberta Pecoraro Elena Maria Scalisi Daniele Tibullo Bianca Maria Lombardo Giuseppina Messina Francesco Loreto Chiara Copat Margherita Ferrante Roberto Avola Giusi D'amante Claudia Genovese Salvatore Antonino Raccuia Maria Violetta Brundo 《Microscopy research and technique》2017,80(11):1215-1220
Honey is a valuable food produced by bees from sugary substances that they gather in nature. The transformation the nectar into honey, by bees, is long and complex. Except for honey, where heavy metals are absent or are found only in traces, the bees and their products have always been considered excellent biomarkers of such contaminants. We have assumed that the absence of heavy metals in honey is due to the presence of a detoxification system in the digestive system of bees, which involves metallothioneins, proteins that have a role in the homeostatic control of essential and non‐essential metals. We have placed the beehives in three different zones: industrial, urban and rural. Investigations were carried out with ICP‐MS method for the detection of heavy metals in the guts of honey bees and honey. The metallothioneins have been identified by Immunohistochemical and Western‐blotting analisys. The investigations have shown the presence of heavy metals only in bees guts but not in honey, while the presence of metallothionein has been highlighted only in epithelium of the honey sac, demonstrating the existence of an efficient system of detoxification of heavy metals. 相似文献
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基于XRF技术的大气重金属在线分析仪的研制 总被引:3,自引:1,他引:2
针对大气中铅、铬、镉等重金属在线监测的应用需求,研制了基于X射线荧光分析技术的大气重金属在线分析仪。该仪器具有可同时监测20多种元素、检出限低、无损快速、使用方便和维护成本低等优点。详细描述了仪器的总体设计及主要结构,展现了仪器性能特点;对仪器进行性能测试,结果显示该分析仪性能稳定,达到国际同类仪器水平。该分析仪监测大气中铅元素浓度结果与ICP-MS(inductively coupled plasma mass spectrometry)分析仪结果对比相对误差在4%以内。将该分析仪应用于杭州某大气监测站,连续监测大气重金属变化情况,实验结果表明该分析仪可靠性高、具有较强的现场应用能力,满足现场应用需求。 相似文献
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Elemental changes in the brain, muscle, and gut cells of the housefly, Musca domestica, exposed to heavy metals 总被引:1,自引:0,他引:1
Tylko G Banach Z Borowska J Niklińska M Pyza E 《Microscopy research and technique》2005,66(5):239-247
The toxic effects of heavy metals on organisms are well established. However, their specific action at the cellular level in different tissues is mostly unknown. We have used the housefly, Musca domestica, as a model organism to study the toxicity of four heavy metals: copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb). These have been fed to larvae at low and high, semi-lethal concentrations, and their accumulation in the head, thorax, and abdomen was subsequently measured in adult flies. In addition, their impact on the cellular concentration of several elements important for cell metabolism-sodium (Na+), magnesium (Mg++), phosphorous (P), sulphur (S), chloride (Cl-) and potassium (K+)-were measured in neural cells, muscle fibers, and midgut epithelial cells. Our study showed that the heavy metals accumulate mainly in the abdomen, in which the concentrations of two of the xenobiotic metals, Cd and Pb, were 213 and 23 times more concentrated, respectively, than in controls. All the heavy metals affected the cellular concentration of light elements in all cell types, but the changes observed were dependent on tissue type and were specific for each heavy metal, and its concentration. 相似文献
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为了分析铅锌矿区土壤重金属在这种情况下的环境行为,通过实验了解这种状况下的重金属累积情况,用到了一级动力学方程以及抛物线扩散方程,得到了土壤中重金属的动力模型。通过数据了解到重金属的浓度先升高,然后不断下降,体积和pH值之间是负相关的关系,和电导率之间是一种正相关关系。 相似文献
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O. V. Moskovkin 《Instruments and Experimental Techniques》2000,43(3):403-405
A circuit for automatic compensation of the ohmic resistance of a solution in a three-electrode chemical cell is described.
This circuit is designed for voltammetry of aqueous solutions of ions of heavy metals and can also be used for the analysis
of the aqueous solutions of other substances. The circuit automatically corrects the voltamperogram offset on the potential
axis by periodically chopping the current through the cell and measuring the voltage across the double layer capacitance.
The compensation error is determined by the parameters of the circuit components and is within 0.1 mV, thus almost completely
excluding the error in identifying ions of heavy metals. 相似文献