超痕量铊的差分脉冲阳极溶出伏安法研究及其应用

随着铊化物的日益广泛应用,不仅污染了环境,且增加了职业性铊中毒的潜在危险性,直接危害人体健康,故对其超痕量的测定日益为人们所重视。 Bonelli等在HAc-NaAc/EDTA介质(pH4.6)中,以差分脉冲阳极溶出伏安法(DPASV)直接测定天然水中铊,电积10分钟,检测限为5.0×10~(-11)M。Lime等采用汞膜电极DPASV法测定了岩矿及生物物质中的铊,电积10分钟,检测限为1ng/g。此法前处理复杂且需特殊仪器。本文以汞膜电极研究了铊的阳极溶出行为,发现在Britton-Robinson(简称BR)溶液中,铊的溶出峰敏锐、加入DCTA能有效地消除镉、铅等金属离子干扰,     

环境领域铊元素的分析技术研究进展EI北大核心CSCD

铊是一种剧毒的蓄积性重金属元素。伴随着含铊矿物资源的开发利用,铊向环境中的迁移已不容忽视,环境铊污染事件时有发生。铊的分析技术对铊污染的防治具有重要意义。环境领域铊的分析技术近年来也有了新的发展。重点对环境水体、土壤、大气中铊元素分析技术的近期发展进行了综述。在电感耦合等离子体-质谱(ICP-MS)、石墨炉原子吸收光谱(GF-AAS)法为主流分析手段的同时,随着铊新型富集技术的应用以及仪器性能的提升,环境铊分析技术呈现出高灵敏、高稳定性的趋势。针对环境领域铊元素分析技术的发展,提出环境样品铊的化学及赋存形态分析、铊的在线监测、与铊高效富集技术的联用以及环境固体废物中铊的分析是其重要的发展方向。     

铊的环境污染与迁移转化

从铊的环境污染途径及其在环境中迁移转化等方面,分析了铊这一分散剧毒元素的表生地球化学行为,环境迁移,分散富集规律和特征,铊的环境污染研究方向和内容。     

电感耦合等离子体质谱法测定环境土壤中的痕量铊及测定干扰的消除

正铊元素虽然在地表分布稀少,但为强烈的神经毒物,对人体的肝、肾有毒害作用。土壤中的铊主要来源于硫化物矿、铅精矿、锌精矿、混合铅锌矿等矿产中,随矿山采选、加工厂废水排放及酸雨洗刷等途径可能迁移到地表水中,而《地表水环境质量标准》(GB 3838-2002)对地表水中铊元素含量的要求非常低,其二级标准限值为0.000 1mg·L~(-1)。因此,建立准确测定环境中痕量铊的方法显得十分有     

乙醚萃取-高分辨率连续光源石墨炉原子吸收光谱法测定金矿石中铊的含量

正铊是一种有毒重金属,铊及其化合物在水体、土壤和植物中的增加,通过食物链进入人体,会给人体带来极大的健康隐患。在自然界中,铊属于分散元素,是亲硫元素,也具有亲石性,主要存在于金、铜、铅、砷、锌和铁等的硫化矿物中。因此,在金矿石的开采及选矿过程中,会对环境造成污染。建立准确可靠的金矿石中铊的测定方法,可对金矿石开发工艺指标控制,资源评价及选冶工艺排放提供可靠的     

铊(Ⅲ)直接氧化鲁米诺化学发光测定岩矿样品中的痕量铊

液相化学发光主要是利用离子的催化作用进行测定。有几种高价金属离子能直接氧化鲁米诺化学发光。U.Fritsch等研究了铊(Ⅲ)在磷酸盐介质中直接氧化鲁米诺化学发光测定微量铊的方法,检测限为0.1ppm。本文在研究介质对铊(Ⅲ)-鲁米诺体系化学发光反应影响的基础上,选择H_3 BO_3-KOH介质测定铊,提高了灵敏度,检测限达到1ng/mL。铊浓度在4×10~(-9)—1×10~(-5)g/mL范围内有良好线性关系。用泡沫塑料从岩矿试液中分离铊。     

平台原子吸收法测定环境和生物样品中的痕量铊

铊及其化合物有剧毒。它的硫酸盐和乙酸盐已作为杀虫剂和灭鼠剂。铊在环境样品中,如土、气、水和植物等,含量很低,但在冶炼厂的回降物中,烧煤的烟道灰和水泥工业的尘埃中均发现有铊。铊可能造成污染及危害人体健康等情况,不容忽视。然而目前缺少灵敏、可靠的监测痕量铊的方法。石墨炉原子吸收法具有灵敏、取样少和操作简便等优点,目前已广泛应用于环境样品和各种材料中痕量元素的测定。但迄今为止,文献中用于测定铊的报导却很少。Welcher首先用石墨炉测定合金中的铊,指出盐酸对铊产生严重的     

铊污染及其生态健康效应

对铊污染及其生态效应，包括铊的地球化学特性、环境分布状况、生理毒性和人体慢性铊中毒的症状作了简要综述，分析了铊污染的来源，提出了铊污染的防治对策。     

聚酰胺富集分离-光度法测定环境样品中痕量铊

提出以聚酰胺树脂为吸附剂,在ＨＣｌ介质中,记和动态操作条件下,对环境样品中一铊的选择性吸附分离方法。树对铊（Ⅲ）有很强的吸附能力,饱和吸附容量为８．８６ｍｇ／ｇ（ｐＨ５的ＨＣｌ介质中）和０．９８ｍｇ／ｇ（１．０ｍｏｌ／Ｌ的ＨＣｌ介质中）。     

可溶性有机质对污染土壤中铊迁移行为的影响

目的 为了查明可溶性有机质（DOM）对土壤中污染元素铊赋存形态的影响,方法 采用形态分级提取方法,将土壤中的铊重金属分成酸可交换态、铁锰氧化物结合态、有机质结合态和残留态4组分,并采用Elan 6100型ICP-MS质谱仪测定各组分中铊的质量浓度.结果 DOM可降低酸可交换态的Tl,增加铁锰氧化物结合态和有机质结合态Tl的百分含量,但对残留态Tl的百分含量没有明显影响.因此,DOM可降低铊在土壤中的活动性,从而改变了铊在土壤中的迁移行为.结论 可溶性有机质（DOM）自身的络合（螯合）能力及其吸附特性是改变重金属铊形态分布的主要因素.     

自然界中铊的分布及对人体健康的影响

铊是一种剧毒且对动植物的新陈代谢不起任何促进作用的金属元素。分布于土壤、水体中的铊及其化合物的污染物可以通过食物链进入生物体,并对生物体特别是人类健康造成巨大的威胁。因此,致力于铊的长远研究对于综合治理铊污染具有十分重要的意义。     

The determination of thallium in sediments and natural waters

Thallium is determined in natural waters (including sea water) by first preconcentrating it by adsorption from oxidizing medium onto a strongly basic anion exchanger as the tetrachlorothallate(III) ion. After elution with sulphur dioxide and evaporation, thallium is estimated either by graphite-furnace atomic absorption spectrometry or by differential-pulse anodic stripping voltammetry. Relative standard deviations of 4% were found for both endpoints at thallium concentrations of 15 ng l^?1. There was good agreement between the results obtained by the two techniques. The technique is also applied to digests from deep-sea sediments.     

Determination of thallium(III) by use of a mercury reductor

A convenient method has been developed for the determination of thallium(III) by using a mercury reductor. Thallium(III) is reduced to thallium(I) in 0.5–4N hydrochloric or sulphuric acid medium and the determination is completed by oxidative titration with potassium bromate. The method is extended to analysis of thallium(III)-thallium(I) and thallium(III)-iron(III) mixtures.     

Investigation of thallium hydride generation using in situ trapping in graphite tube by atomic absorption spectrometry

Thallium hydride was generated from aqueous solutions by merging sample and sodium tetrahydroborate reductant in a batch system. In situ preconcentration of volatile thallium hydride in a preheated graphite furnace coated with palladium, which was used as both the collection medium and atomizer, greatly improved the sensitivity for the determination of thallium by hydride generation atomic absorption spectrometry. The presence of tellurium can increase the generation efficiency of thallium hydride. The operating conditions were optimized. The calibration graph is linear up to 100 ng and the characteristic mass for thallium was 0.92 ng which is seventeen times lower than that obtained with the heated quartz tube atomizer.     

Extraction—spectrophotometric determination of traces of thallium in lead,cadmium, indium and zinc metals with tri-n-octylamine

A sensitive spectrophotometric method is described for the determination of thallium in lead, cadmium, indium and zinc metals. Optimal conditions have been established for the extraction and determination of thallium. Thallium is extracted as its bromo complex with tri-n-octylamine and then converted to an iodo complex, the absorbance of which is measured at 400 nm. As little as 1 p.p.m. of thallium in lead, cadmium and zinc metals, and 2 p.p.m. of thallium in indium metal can be determined.     

Thallium(I) supramolecular compounds: Structural and properties consideration

During the last two decades, supramolecular compounds and especially coordination polymers have received great attention and the number of their synthesized compounds is still growing, which is mainly due to their potential application in various fields such as microelectronics, nonlinear optics, ion exchange, catalysis, gas storage, separation and luminescence. Formation of polymers with main group metal ions such as thallium(I) is disproportionately sparse when compared with those of other metals. Because of the interest structures, properties and applications of thallium polymers, it is necessary to understand thallium's ability to bind donors and form supramolecular compounds. This review tries to give an overview of all supramolecular compounds which were reported from thallium(I) after 1990 and to investigate their properties and applications. Thallium(I) usually forms neutral species and exhibits greater tendency to forming one-dimensional supramolecular compounds. Thallium(I) also favors secondary interactions on its coordination sphere (especially with unsaturated carbon atoms forms organometallic polymers) with stereochemically active lone pair and hemidirected coordination sphere around it.     

Determination of thallium in biological samples

Determination of thallium has become a major interest because of its high toxicity, especially as the monovalent cation. Thallium poisoning in the human body must be checked quickly by analysis of biological samples. This review highlights the development of highly sensitive detection techniques applied to the determination of thallium in biological samples, with or without pretreatment, based on the literature compiled in Analytical Abstracts from 1990.     

Biamperometrische Indikation in der Chelatometrie

Zusammenfassung Der Endpunkt von komplexometrischen Titrationen (mit ÄDTE) kann biamperometrisch besonders gut indiziert werden, wenn man zur Titrationslösung eine geringe Menge Thallium(III)-ÄDTA zusetzt. Auf diese Weise erhält man nach dem Äquivalenzpunkt einen starken Anstieg des Diffusionsstromes. An die Elektroden wird eine Spannung von 1,0 V angelegt. Thallium(III)-ÄDTA ist am wirksamsten im pH-Bereich zwischen 6 und 10.

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Biamperometric indication in chelatometryImprovement of the end-point indication by means of thallium(III)-EDTA

The biamperometric indication of chelatometric titrations with EDTA is greatly improved, if a small amount of thallium(III)-EDTA is added to the solution to be titrated. Thus, an appreciable increase of the diffusion current is obtained after the equivalence point. A voltage of 1,0 V is applied to the platinum electrodes. Thallium(III)-EDTA is most effective in the pH-range between 6 and 10.