微波消解-原子荧光光谱法测定番茄不同部位中微量汞

在汞污染的土壤上种植不同品种番茄 ,采用微波溶样技术和原子荧光光谱法 ,测定番茄不同部位的汞含量 ,初步研究了汞在番茄植株各个部位的分布情况 ,同时确定了微波消解该类样品的最佳条件 ,优化了原子荧光光谱仪的工作参数。该方法具有快速、简便、准确等特点 ,汞含量在0.01～20μg/L范围内线性良好 ,相关系数r=0.9998。研究结果还表明 ,汞含量在番茄各部位中的分布规律是根 叶>茎 果实 ,只有1/10的供试番茄品种在汞胁迫下果实中汞含量超标 ,为评价番茄作为菜蔬食品在生产中受汞污染的风险以及发展新的重金属污染土壤的修复技术提供依据     

土壤-植物系统中的汞污染与农产品安全生产

对农产品的汞污染及其安全生产问题作了综述，内容包括：汞在土壤．植物系统中的循环，汞污染对农产品安全生产的威胁与对策措施，例如，可利用植物生物技术选育低积累汞的作物基因型、采取植物修复及相应的农艺措施，以进行有效的农产品安全生产与调控，减小环境中过量的汞对土壤．植物系统和食物链造成的危害，最终保障人体的健康。     

超声水浴-王水浸提-全自动测汞仪测定重度污染土壤中的总汞

为准确测定重度污染土壤中的总汞含量,本文建立了以超声水浴辅助王水浸提,使用全自动测汞仪测定的方法。 通过单因素实验考察了王水用量、超声时间和超声温度对土壤中总汞测定的影响,得到最佳前处理方法,最后应用建立的方法对重度污染土壤进行方法验证。确定了0.5 g土壤样品中加入5 mL的王水溶液,放入超声波清洗器中70℃水浴下超声提取70 min,使用超纯水定容至50mL的前处理方法,直接进样测定的实验方法。对该实验进行验证,结果表明,该方法汞低标准曲线汞含量在0～20ng范围内线性良好,相关系数R=0.9995;汞高标准曲线汞含量在20～150 ng范围内线性良好,相关系数R=0.9993;方法检出限为0.0055 mg/kg,方法定量下限为0.022 mg/kg;通过对土壤样品及土壤加标样品的测定,回收率为90.40～116.80%,表明该方法的准确度较高,RSD为1.89～3.34%（n=6）,表明该方法的精确度较高。超声水浴-王水浸提-全自动测汞仪法用于测定重度污染土壤中的总汞,前处理简单,自动化程度较高,可快速,高效的用于重度污染土壤总汞测定工作。     

DMA-80 型直接测汞仪测定食品中汞

汞可引起人类急、慢性中毒,自工业革命以来,汞在全球大气、水和土壤中的含量已增加了3倍左右.在工业区附近汞的含量更高,汞污染的不断加剧对人类健康和环境造成了极大危害.     

发现汞矿区稻田甲基汞主要来源北大核心CSCD

中科院地化所冯新斌团队,以贵州省万山汞矿区不同污染类型（土法炼汞区和废弃汞矿区）的水稻田为研究对象,对汞矿区水稻田各介质中汞的分布特征、主要来源及污染状况进行了全面系统的研究。相关成果日前发表于《环境污染》、《生物地球科学》。稻田作为一种特殊的湿地生态系统,其间歇性的淹水环境有利于土壤中汞的甲基化作用。因此,     

发现汞矿区稻田甲基汞主要来源

正中科院地化所冯新斌团队,以贵州省万山汞矿区不同污染类型(土法炼汞区和废弃汞矿区)的水稻田为研究对象,对汞矿区水稻田各介质中汞的分布特征、主要来源及污染状况进行了全面系统的研究。相关成果日前发表于《环境污染》、《生物地球科学》。稻田作为一种特殊的湿地生态系统,其间歇性的淹水环境有利于土壤中汞的甲基化作用。因此,     

电感耦合等离子体质谱法测定地表水中汞及其记忆效应的消除

<正>汞作为一种高毒性的重金属元素,其危害性已广为人知。工业及农业活动中都有可能造成水环境中汞污染,汞排入水中后,受污染水体的鱼体内甲基汞含量比水中高上万倍,汞在水体、土壤、大气和生物圈中迁移和转化并对人类的健康产生威胁[1-3]。     

益智及其种植区土壤中汞含量研究

采用氢化物原子荧光法测定了益智种植区土壤与益智各部位中的痕量汞,比较了HNO3＋HF＋H2O2、HNO3＋HF、HNO3＋HClO43种混酸消解体系的消解效果。结果表明,HNO3＋HF＋H2O2为最佳消解体系;样品加标回收率为93．70％～102．25％;土壤及益智果实、根、茎、叶中汞含量分别为0．3583、0．1632、0．0950、0．0700、0．0747mg·kg^-1,土壤中汞在益智果实、根、茎、叶间的迁移率分别为45．55％、26．51％、19．52％、20．83％,土壤及益智各部位的汞含量均在国家规定标准以内。说明海南益智种植区地理环境良好,未受到汞污染。     

原子荧光测汞法

汞是自然界中分布较广的元素之一。特别在金属矿床上层的土壤和空气中含量较高,几乎在所有矿物中均含有汞。所以,测定大气中的汞已用来探测地下矿藏。汞出现在人类生活中,历史很久。现代已成为许多工业及科学实验室中不可缺少的物质。由于人们的生产活动,破坏了汞的自然平衡,使环境中的汞超过了本底含量,而使环境遭到污染。     

无焰原子吸收分光光度法测定蘑菇罐头中的痕量汞

近年来,在一些资本主义国家中,由于“公害”问题严重,多次发生汞污染食品的中毒事件,因而人们迫切要求了解生活环境中汞的污染情况,从而促进了痕量汞测定方法向着高灵敏、准确、简单、快速的方向速迅发展。无焰原子吸收分光光度法由于灵敏、快速、简单、准确,目前已被认为是测汞的最好方法,已广泛应用于空气、水、河流沉积物、血、尿、鱼、蛋、谷物、金属、岩石和土壤中痕量汞的分析。无焰法测汞的基本原理是利用金属汞在常温下具有足够大的蒸汽压和在空气中不易被氧化的特性,用还原剂将试样中的汞离子还原成金属汞后,随即通空气流将汞蒸汽导入两端具有石英窗的吸收管中,     

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。     

土壤和沉积物中汞形态分析的研究

本文根据各种形态汞氧化还原和溶解性质的差别建立了土壤和沉积物中汞形态分析的系统方法.研究了测定各形态汞的实验条件,考察了各形态汞相互间的干扰情况,并对一些实际样品进行了系统分析.结果表明,所建立的方法可用于土壤和沉积物中汞赋存形态的研究.     

Distribution of mercury in soil organic matter fractions obtained by dissolution/precipitation method

Sequential multistep procedure, usually used for the fractionation and characterization of soil organic matter was tested for Hg content in the individual steps and fractions. Under general laboratory conditions serious problems have arosen during the attempt in the Hg mass balance calculation. Several sources of Hg contamination were recognized. The most serious was the background concentration of Hg even in research grade chemicals (what is in general not declared) and laboratory air. The work on operational Hg speciation as non-humic bound, humic acid, fulvic acid bound proceeds from the established status-quo on distribution of mercury of soil organic matter.     

Fractionation studies of mercury in soils and sediments: A review of the chemical reagents used for mercury extraction

Mercury in contaminated soils and sediments could be extracted by various chemical reagents in order to determine the different mercury species and partitions, providing useful information of toxicology, bioavailability and biogeochemical reactivity. Unfortunately, at present, neither specific extractants nor standard protocols exist for the isolation of particular mercury species. Although there has been considerable research focused on reagents for extracting mercury species, there is still little consensus. Thus, workers are advised to select the most appropriate reagent based on the nature of their sample, and to take all possible steps to validate the analyses performed. Therefore, the aim of this paper is to review the current reagents used for determining total mercury and its speciation as well as fractionation such as methylmercury, ethylmercury, elemental mercury, mercury sulphide and organically bound mercury by supposed selective (one reagent) and sequential (several reagents) extractions. The gathering information presented here bring to light the need for standard protocol for which the used chemical reagents should take into account the particular chemistry of mercury associated with specific properties of soil and sediment. Beside this required scheme, appropriate reference materials are also demanded.     

The Speciatipn of Mercury in Soil and Sediment

A systematic procedure for speciation of mercury in soil and sediment was established Experimental conditions were optimized,and interference between different species was studied.The procedure was applied to practical samples and the results obtained were satisfactory.     

Characterization of mercury species in soils by HPLC-ICP-MS and measurement of fraction removed by diffusive gradient in thin films

The properties and behaviour of Hg depend on both the oxidation state and the chemical form: the bioavailability, toxicity, persistence and accumulation of mercury in the food web are strongly influenced by chemical speciation. The present work aims to determine the chemical forms of mercury present in soil and to evaluate the fraction of mercury in soil solution available to plants. In order to do this, we analyzed eight samples of contaminated soils with Hg concentrations ranging from 1.31 to 21.7 mg kg⁻¹, collected from different depths (0–10 and 40–50 cm) close to an abandoned industrial site in Val Basento (southern Italy). Two innovative analytical techniques were used: HPLC–ICP-MS and diffusive gradient in thin films (DGT). The analytical procedure was validated using ERM 580-certified sediment and spiked samples in the case of HPLC–ICP-MS, and by a performance test in the case of DGT. In all samples, the only species found in soil and soil solution was MeHg⁺ and Hg²⁺. In soil, the MeHg⁺/Hg_tot ratio ranged from 0.05% to 0.82%; total mercury in soil solution was less than 0.01% of total mercury in soil. The percentage of MeHg⁺ in soil solution varied considerably (from 0% to 50%), with a maximum concentration of 0.02 mg L⁻¹. The root available concentration evaluated by DGT is comparable to the total mercury content of the soil solution measured by HPLC–ICP-MS. The DGT results suggest that all mercury in solution is available for uptake in DGT, and that mercury is supplied from soil to solution. However, for all samples the soluble and root available (DGT-labile) fractions of mercury are generally very low with respect to the total mercury concentration. This study confirmed that both HPLC–ICP-MS and DGT techniques are suitable tools for the estimation of Hg root availability and in assessing the risk from contaminated soils.     

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     

汞的形态分析进展

从汞的分离富集出发,按测定方法分类,对近年来国内外有关汞的形态分析的研究进展进行了综述（引用文献６８篇）。     

The pzc of mercury in the presence of humic acids and their complexes with aluminium

Variation of the lifetime of a mercury drop with potential was used to determine the pzc of mercury in the presence of soil humic acids and their aluminium complexes. In all cases there was an overall net shift in the pzc in the cathodic direction. Variation in the extent of the shift with pH and concentration indicated greater adsorption of negatively charged species. The shift was smaller in the presence of aluminium humates, probably due to a decrease in the negative charge of the humic acid molecules after complexing. The use of electroanalytical techniques for metal speciation studies in soils and natural water, if humic materials are known to be present, might therefore be limited.     

大气中活性气态汞的分析方法和赋存转化

活性气态汞(Reactive gaseous mercury,RGM),在大气环境中通常被认为是气态的氧化汞,主导大气汞沉降过程,对汞的全球循环至关重要.本文详细介绍了RGM的多种采样和分析方法,讨论并比较了当前技术的优势和局限性;对RGM在大气中的生成、赋存、清除等环境过程以及相关的机制进行了梳理,并探究各过程在大气...