环境样品中痕量元素的化学形态分析Ⅱ．砷汞镉锡铅硒铬的形态分析

环境中元素的生物有效性和毒性依赖于其存在的化学形态。文章依据文献的有关报道介绍砷、汞、镉、锡、铅、硒和铬在环境中的分布、毒性及它们在环境样品如水、土壤、沉积物和生物体中的形态分析方法,包括分析物的保存、提取、分离和检测。引用文献120篇。     

环境矿物材料治理镉（Cd^2＋）污染研究进展

近年来,环境矿物材料以其经济、有效、无二次污染等特点,在重金属废水处理和土壤修复方面显示出了众多优势,可替代传统的镉污染处理方法。本文综述了国内外环境矿物材料在处理镉污染方面的研究进展,并对今后应用环境矿物材料治理镉污染提出了一些建议。     

Mechanisms of physico-chemical interaction of mercury with river sediments from a gold mining region in Brazil: Relative mobility of mercury species

Mercury accumulation in the food chain, as a consequence of gold recovery in Brazil, has been an issue of concern. Reactions of Hg in the environment are quite complex, and can involve various Hg chemical species. Laboratory experiments were carried out on Hg⁰ solubility, Hg complexation and sorption on river sediments from a gold mining region in Brazil. The reactivity and the mobility of Hg species were considered. Results indicate that methyl mercury is more mobile than ionic mercury, and that the presence of humic acid enhances drastically the solubility of Hg⁰. The soluble complex formed has a relatively lower interaction at the sediment/water interface and is more prone to spread through the aquatic environment.     

Mercury mobility at the Carson River Superfund Site, west-central Nevada, USA: Interpretation of mercury speciation data in mill tailings, soils, and sediments

The Carson River Superfund Site in west-central Nevada is an area of Hg-contaminated soil, sediment, water, air, and biola resulting from the amalgamation milling of Ag-Au ores of the Comstock lode worked approximately a century ago. In order to develop an understanding of the behavior, transport, and fate of Hg at this site, a technique was developed to estimate the proportions of total, elemental, exchangeable, organic, and sulfide Hg in soils, sediments, and tailings.Results of this analysis performed on active Carson River sediments indicate that Hg is selectively dissolved out of Hg-Au amalgam particles and subsequently adsorbed to fine-grained sediments which are then deposited in downstream, low-energy reaches of the Carson River and Labontan Reservoir. In the relatively more-reducing environment of the reservoir Hg appears to be converted, in large part, to relatively-insoluble HgS.The original elemental form of Hg released to the environment is the chemical form which is still dominant in most highly-contaminated soils, sediments, and tailings. Deeper, more-reducing soil horizons, however, appear to fix a significant portion of the Hg as HgS, analogous to the Lahontan Reservoir example described above. This fixation as HgS is documented to be largely limited to higher-sulfur areas where sulfide minerals from the Comstock ores increase the total sulfur concentrations of contaminated soils, sediments, and tailings.     

铜与间氯偶氮安替比林显色反应研究及铜的形态分析

在ｐＨ４８的邻苯二甲酸氢钾＿ＮａＯＨ缓冲介质中，Ｃｕ（Ⅱ）与间氯偶氮安替比林形成１∶２的蓝色配合物，其最大吸收峰位于６３０ｎｍ处，表观摩尔吸光系数为４２６×１０４Ｌ·ｍｏｌ－１·ｃｍ－１，Ｃｕ（Ⅱ）的质量浓度在０～２ｍｇ／Ｌ时符合比尔定律。应用该法测定了桃叶及牛肝标样中的铜含量，测定值与标准值一致。结合活性炭分离，建立了铜的形态分析流程，并测定了茶汤中铜的各种主要形态及其分布。     

气相色谱和薄层色谱法在形态分析中的应用

评述了气相色谱和薄层色谱法用于氯、溴、碘、硫、硒、碲、铬、氮、磷、砷、钒、碳、锡、铅、铁和汞１６种元素的不同形态分析的进展。这些形态包括不同价态、有机态、无机态、阳离子和阴离子态等。由于气相色谱和薄层色谱法都具有分离和检测两种功能结合的特点，因此它们是用于元素形态分析的有效和方便的方法。引用１９８０～１９９４年文献９２篇     

一种新的流动注射在线共沉淀技术的研究及应用

建立了应用流动注射在线共沉淀分离富集火焰原子吸收法测定天然水样中痕量铬的价态分析方法。利用铬（Ⅲ）在碱性条件下与氢氧化镧形成共沉淀而与共存离子分离并得到富集，沉淀不需过滤，直接用稀盐酸从编织反应器（ＫＲ）中溶解并洗脱下来，用原子吸收测定。本体系的浓集倍率２２，检出限（３σ）０．８μｇ／Ｌ，相对标准偏差（ｎ＝１１）２．７２％，用水标样考察，分析结果与推荐值相符。该方法成功地用于天然水中铬的快速测定。     

Distribution and Elimination of Lead Species in Soils Related to GAP of Chinese Medicinal Materials of Ligusticum Chuanxiong Hort

In this paper, the sequential extraction procedure was used for the selection of fractions of lead in seven stages corresponding to lead exchangeable, lead bounded to carbonates, to manganese oxides, to organic matters, to amorphous iron, and lead associated to crystallized iron, and to residuals. The vertical distributions of lead species were carried out in the soils related to good agriculture progress (GAP) of Chinese medical materials of Ligusticum chuanxiong Hort in Dujiangyan city and Wenchuan County, Sichuan Province. Based on those researches, it is found that the plant of Glycine Max (L.) Merr. has the character of lead enrichment and sorption, which is not reported in the literature. Using Glycine Max (L.) Merr. alternate planting with Ligusticum chuanxiong Hort is a valuable recommended in order to produce a high quality Chinese medical materials in order to eliminate the barrier on the beyond the lead limit for the import and export of Ligusticum chuanxiong Hort.     

非饱和土中镉离子传输模型参数反演

使用自行设计的的真空实验装置,采用一维实验室土柱实验方法在不同实验条件下进行了15组实验,并基于实验所得的穿透曲线,使用梯度正则化方法反演得到了镉离子在8种葡萄牙土样和1种比利时土样中相应的传输模型参数。同时通过数值模拟实验验证了梯度正则化方法的有效性和可靠性,进而证明所得结果是有效的。     

A Reflection on Mg, Cd, Ca, Li and Si Isotopic Measurements and Related Reference Materials

This contribution aims to report the reflections we had with the scientific community during two international workshops on reference materials for stable isotopes in Davos (2002) and Nice (2003). After evaluating the isotopic homogeneity of some existing reference materials, based on either certificates, literature data or specific inter-laboratory rounds, we confirm these as primary reference materials or propose new ones relative to which stable isotope compositions should be reported. We propose DSM-3 for Mg, NIST SRM 915a for Ca, L-SVEC for Li and NBS28 for Si. Cadmium does not yet have a well identified delta zero material, although three commercial mono-elemental Cd solutions have yielded the same isotopic composition relative to one another. In order to scale the linearity of any mass spectrometer, some secondary reference materials are also proposed: Cambridge-1 solution for Mg, the "Münster-Cd" and JEPPIM Cd solutions for Cd and the "Big Batch" silicate for Si. The team from Nancy propose to prepare a mixed spike solution for Li isotopes. Well-characterised natural samples such as ocean or continental waters, diatoms, sponges, rocks and minerals are needed to validate the entire analytical procedure, particularly to take into account the effect of sample mineralisation and of chemical manipulations for elemental separation prior to analysis.