液相色谱-原子荧光光谱法测定水产品中汞形态的含量

正汞在自然界中分布极广,是工业生产、科学研究不可缺少的物质之一,在人类生活中起着重要的作用。有机汞化合物在农业中常用作杀虫剂和杀菌剂,无机汞和单质汞在生活中也普遍使用[1]。但汞是对人类和高等生物最具危害的元素之一,它是污染环境的主要元素之一。汞化合物的毒性与其含量和不同的化学形态有关,因此不同形态的汞对人体     

元素形态分析的计量研究进展

元素的生理活性或毒性依赖于其不同的化学形态,如甲基汞、乙基汞等有机汞化合物的毒性远大于无机汞:砷糖、砷甜菜碱等有机砷化合物的毒性要远小于无机砷;而硒代蛋氨酸已经没有无机硒化合物的毒性,甚至成为一种营养物质.因此,检测元素的不同形态化合物,对于考察元素在生物体中和环境中的化学行为与迁移行为具有重要意义.元素形态分析在食品安全、环境保护和临床检验等领域有着广阔的发展前景,建立我国元素形态分析量值溯源体系十分重要.     

环境汞污染

由于特殊的物理化学性质和强的毒性,汞已经成为全球关注的污染物.本文对目前大气汞的来源、汞在大气中的形态分布及在全球大气分布的特点和汞在大气中的迁移转化规律等方面进行了详细地介绍,提出了大气汞研究的展望.评述了近年来水生生态系统汞的生物地球化学循环研究领域的新进展及存在问题,提出了对汞甲基化机理认识的研究要进一步加强的观点.对汞矿开采和混汞法炼金区环境汞污染及对居民健康的危害研究进展进行了详细地评述,指出矿区居民汞暴露的主要途径.最后,本文还总结了目前人体暴露不同形态汞对人体健康影响的最新进展.     

高效液相色谱-原子荧光光谱法应用于不同营养级鱼肌中汞的形态分析

汞是环境中最具威胁的元素之一,各形态汞的毒性不同,并且会随食物链的传递积累. 因此,同时检测鱼肌中不同形态的汞含量,并分析其在不同生境及营养级的差异性具有相当重要的研究价值. 通过高效液相色谱-原子荧光光谱联用法改变流动相中甲醇的浓度、光电倍增管负高压、空心阴极灯电流、还原剂及载流的浓度等条件,优化了不同汞形态组分的分离程度和响应值. 在优化的试验条件下,将鱼肌样品经离心、过柱、洗脱等步骤处理后,由液相色谱分离,最终通过原子荧光法检测提取溶液中3种汞形态. 结果表明,二价汞、甲基汞、乙基汞在0.2~10.0 μg/L质量浓度范围内线性关系良好,相关系数均大于0.999 9,方法检出限在0.39~0.82 μg/kg之间,平行样品相对标准偏差(RSD)均小于4.0%. 方法前处理简单,准确度高,适用于鱼肉中汞的形态分析. 方法应用于不同生境、不同营养级的鱼肌样品检测,可观察到不同营养级样品结果明显的差异性及同类样品间的相关性.     

冷蒸汽-原子荧光光谱法测定水样中3种形态的汞北大核心CSCD

汞在环境中的迁移和毒性,随其形态不同而不同。仅测定其总量的方法已不能适应汞化学的深入研究[1],对形态汞的测定,难点在测定前的化学处理[2]。本工作在文献[1-6]的基础上,提出了冷蒸汽发生-原子荧光光谱法测定水样中3种形态汞（无机汞、有机汞和总汞）,以应对各种环境影响评价的不同要求。1试验部分1.1仪器与试剂WGYSIA型数字原子荧光测汞仪,7663型远红外辐射干燥箱,1.0mL和10μL微量进样器。     

土壤样品中汞的形态分析研究进展

土壤中汞的活性及其生物有效性因其赋存形态不同而存在差异,汞赋存形态分析已成为环境科学领域研究的热点之一。归纳总结了近年来土壤环境中汞赋存形态分类、样品预处理技术和汞形态分析技术研究进展,指出了未来的发展方向。     

冷蒸汽-原子荧光光谱法测定水样中3种形态的汞

<正>汞在环境中的迁移和毒性,随其形态不同而不同。仅测定其总量的方法已不能适应汞化学的深入研究[1],对形态汞的测定,难点在测定前的化学处理[2]。本工作在文献[1-6]的基础上,提出了冷蒸汽发生-原子荧光光谱法测定水样中3种形态汞(无机汞、有机汞和总汞),以应对各种环境影响评价的不同要求。1试验部分1.1仪器与试剂WGYSIA型数字原子荧光测汞仪,7663型远红外辐射干燥箱,1.0mL和10μL微量进样器。     

沉积物样品中痕量元素汞的形态分析研究进展

归纳总结了沉积物中汞形态分析研究进展,内容包括沉积物汞的赋存形态,样品的预处理和不同形态汞的原子光谱法、色谱法、电感耦合等离子体质谱法及联用技术等分析方法,指出了存在的问题和未来的发展方向。     

洗选过程对宁武煤中汞迁移和热释放的影响特性

采用逐级化学提取和热分析方法,选取宁武煤田某洗煤厂原煤及洗选产物为研究对象,在汞质量平衡基础上对煤中汞赋存形态进行分类并验证,进而考察了洗选过程对煤中汞迁移行为和热释放的影响特性。结果表明,洗选过程在降低原煤灰分和硫分含量的同时也改变了汞的富集规律,引起了汞的重新分配;样品中汞元素与灰分和硫含量之间的线性相关性分别为0.89和0.99,原煤中汞主要以无机结合态存在,其迁移行为受控于无机矿物质迁移,洗选后矸石总汞绝对含量较原煤增加了322.8%,而精煤汞含量降低至原煤的40%,汞脱除率达到56.4%;洗煤产物中汞富集程度的差异与其在原煤中赋存形态密切相关,其中,矸石中硫化物结合态汞的占比高达56.6%,而精煤和煤泥中有机结合态汞较原煤中均有所提高;相同温度下汞在煤泥中释放率最大,矸石中最小,所有样品中汞至650℃均接近完全析出;煤中汞热释放特性也与其赋存形态密切相关,不同热解温度段汞热释放行为由煤中汞的固有赋存形态所决定,其中,有机结合态汞随有机质分解在300℃已大量逸出,而硫化物结合态汞分解温度主要为400-600℃。     

聚合Al13晶体的制备及表征

近几十年来 , 环境污染的日益严重使人们对健康问题和全球生态系统越来越关注 ?由于一个元素的生物可给性在很大程度上取决于它存在的物理化学形态和浓度 , 准确测定环境和生物体系中的痕量元素的不同形态是研究这些元素的生物毒性 ? 生物有效性和传输机理的关键 ?形态分析成了     

Some aspects of speciation and reactivity of mercury in various matrices

Speciation of mercury compounds in environmental and biological samples requires different techniques and different approaches. This speciation is mandatory to explain the toxicity, the reactivity and the bioavailability of mercury. It is dominated by inorganic mercury species Hg(II) and Hg(0), and the organic mercury species CH₃Hg and (CH₃)₂Hg. In this paper, some aspects of mercury speciation are presented in terms of:- mercury reactivity (Hg(II) complexation and reduction),- mercury species distribution in the main compartments of the environment     

灰色关联识别在发汞影响因素研究中的应用

应用灰色关联识别,对山西地区人体中汞浓度的主要影响因素从总样本,性别,区域三个不同角度进行排序,分析结果表明,山西整体生活环境中[Hg]在正常上限值内,各区域汞污染水平及污染途径及具有明显的区域性。     

Preconcentration and Speciation of Mercury Compounds In Wastewater Using Dithizone Impregnated UHMWPE Membrane and Reverse Phase Liquid Chromatography

Mercury occurs in the environment in various forms such as elementary mercury, inorganic mercury and organic mercury. Recently,extensive damage has been caused to the environment by mercury used in a number of industrial products such as paints, preservatives, paper,pesticides and cosmetics.     

Determination of Mercury by Inductively Coupled Plasma—Mass Spectrometry

To control the amount of mercury polluting our environment, mercury has to be monitored in all areas of modern life. This requires fast and easy-to-use methods that permit the determination of mercury at levels of micrograms per liter. Up to now mercury ultratrace determination has required preconcentration or amalgamation in order to improve detection limits. This decreases accuracy of determination, introducing a longer manipulation of the sample. Inductively coupled plasma—mass spectrometry (ICP-MS) allows a direct determination of ultratrace mercury, due to the choice of interference free isotopes by the mass spectrometer detector. In fact, the detection limit for mercury by ICP-MS is 0.001 ppb. In the present work results of Hg determinations in different matrices by ICP-MS are reported. ICP-MS technique results are better than those of FIMS-100. This technique is applicable to different solid (minerals and atmospheric particulate) and liquid matrices with elimination of interferences. For solid matrices methods of attack and dissolution are reported.     

Determination of the different states of mercury in seawater near the Vlora and Durres Bays

Because of the toxicity and mobility of organic mercury, there is a need for determination of organic and inorganic mercury at very low concentrations in the environment, especially in seawater. A procedure for extraction and determination of low concentrations of the different states of mercury - total, inorganic, and organic - in seawater, by cold vapour atomic absorption spectroscopy (CVAAS) is described.Inorganic mercury only was directly reduced to the Hg(0) state by tin(II) chloride under strongly acid conditions (H(2)SO(4)) and mercury metal (Hg(0)) was determined by cold vapour atomic absorption spectroscopy. Organic and inorganic mercury were extracted, with toluene, as the bromide derivatives and re-extracted, together, into ammonium chloride solution. Organic mercury was converted into inorganic mercury by thermal digestion at 80-90 degrees C in the presence of strong oxidants. These two states of mercury were determined together as total mercury. Inorganic mercury was measured directly after pre-concentration of the sample by toluene extraction. Toluene dissolved in aqueous phase after re-extraction of the sample was removed by heating for 30 min at 80-90 degrees C. Organic mercury was calculated as the difference between total and inorganic mercury.The sensitivity of the method is 0.0001 ng mL(-1) Hg, depending on sample volume.     

痕量汞的光谱分析

本文介绍采用发射光谱法,将粉末样品直接倒入石墨室电极中,以直流电弧为光源,靠电极的热传导使试样缓慢升温,充分利用汞的分馏效应,实现汞与基体元素的有效分离,测定下限达到0.01ppm。单次摄谱RSD为9.7%。对影响汞谱线强度的因素,如样品组成,烘样时间,电流强度,上电极形状等进行了对比试验。发现汞的测定不受样品组分的影响。曾用该法进行了上万个地质、土壤、环保等样品的测定,都获得了比较满意的结果。方法快速、简便、经济,适用于生产中大批量分析任务。     

Biotransformation fate and sustainable mitigation of a potentially toxic element of mercury from environmental matrices

The deposition of potentially toxic mercury (Hg) in various ecosystems and subsequent entry into the food chain pose serious concerns to the ecosystem, biodiversity, and public health. In terms of toxicity, Hg is considered as a neurotoxin and capable to augment in food chains and bind to the thiol functional entity in living tissue. Moreover, methylated mercury (CH₃Hg⁺) is a highly toxic form of mercury and extremely difficult to remove from living bodies. Mercury methylation is mainly conducted by microbial and/or chemical processes under appropriate conditions. The mechanisms associated with mercury methylation inside the environment, their sources, production/degradation rate, and transport into the living organisms are not well understood. In addition, efficient and sustainable remediation strategies are essential to employ for mercury removal. Therefore, this review signifies a possible mechanism for mercury methylation and its transportation in the environment, including molecular mechanisms and genes associated with microbial-mediated mercury methylation, and identifies the gaps in existing research. The transport of Hg into the human body and associated health risks are given with suitable examples. Moreover, the escalating anthropogenic activities, the rate-limiting factors, and the sustainable remediation strategies implemented for mercury removal from the environment are discussed. This study will provide a scientific base, direction, and progress in future studies.     

Analysis of sorption and bioavailability of different species of mercury on model soil components using XAS techniques and sensor bacteria

The present work studies the adsorption behaviour of mercury species on different soil components (montmorillonite, kaolinite and humic acid) spiked with CH₃HgCl and CH₃HgOH at different pH values, by using XAS techniques and bacterial mercury sensors in order to evaluate the availability of methyl mercury on soil components. The study details and discusses different aspects of the adsorption process, including sample preparation (with analysis of adsorbed methyl mercury by ICP-OES), the various adsorption conditions, and the characterization of spiked samples by XAS techniques performed at two synchrotron facilities (ESRF in Grenoble, France and HASYLAB in Hamburg, Germany), as well as bioavailability studies using mercury-specific sensor bacteria. Results show that XAS is a valuable qualitative technique that can be used to identify the bonding character of the Hg in mercury environment. The amount of methyl in mercury adsorbed to montmorillonite was pH-dependent while for all soil components studied, the bond character was not affected by pH. On the other hand, clays exhibited more ionic bonding character than humic acids did with methyl mercury. This interaction has a higher covalent character and so it is more stable for CH₃HgOH than for CH₃HgCl, due to the higher reactivity of the hydroxyl group arising from the possible formation of hydrogen bonds.The bioavailability of methyl mercury adsorbed to montmorillonite, kaolinite and humic acids was measured using recombinant luminescent sensor bacterium Escherichia coli MC1061 (pmerBR_BSluc). In case of contact exposure (suspension assays), the results showed that the bioavailability was higher than it was for exposure to particle-free extracts prepared from these suspensions. The highest bioavailability of methyl mercury was found in suspensions of montmorillonite (about 50% of the total amount), while the bioavailabilities of kaolinite and humic acids were five times lower (about 10%). The behaviour of methyl mercury in the presence of montmorillonite could be explained by the more ionic bonding character of this system, in contrast to the more covalent bonding character observed for humic acids. Thus, XAS techniques seem to provide promising tools for investigating the mechanisms behind the observed bioavailabilities of metals in various environmental matrices, an important topic in environmental toxicology.     

Detoxification of mercury in the environment

In this study, a green chemistry approach was developed as an option for remediation of toxic mercury in the environment. Twenty mercury compounds were treated with an environmentally friendly agent cyclodextrin to produce stable non-toxic mercury in soil and water. The binding efficiency was determined using high performance liquid chromatography with diode-array detection. The stability of the cyclodextrin mercury complexes toward environmental microorganisms in water was estimated under OECD guidelines using gas chromatography–mass spectrometry. The toxicity of the cyclodextrin mercury compounds to terrestrial organisms was investigated by use of internationally recognized toxicity methods using mercuric acetate as a model contaminant. Key process conditions, for example pH, temperature, and amount of detoxifying agent were investigated and found to have significant effects on the toxicity of mercury. It was found that organic and inorganic mercury pollutants could be mineralized in the environment with cyclodextrins. The bound mercury compounds resisted biodegradation and were found to be non-toxic to environmental microorganisms under laboratory conditions.