催化－导数分光光度法测定石蜡中的痕量锰

本文提出催化－导数分光光度法的原理，并将此原理用于锰（Ⅱ）在碱性介质（ｐＨ值９．８）中催化过氧化氢氧化钙红（ＣＲ）褪色￣［１］的反应，成功地测定了石蜡中的痕量锰。本文还详细地考查了萃取分离干扰离子的条件。其表现摩尔吸光系数为７．４×１０￣７Ｌ．ｍｏｌ￣（－１）．ｃｍ￣（－１），最低检测限为２．５ｎｇ／２５ｍＬ，该法的灵敏度为一般催化法对应反应体系的５．９倍。     

Critical comparison of alternating current and differential pulse voltammetry in the determination of some heavy metals in sea-water

A critical comparison of phase-selective fundamental harmonic a.c. anodic stripping voltammetry and differential pulse anodic stripping voltammetry for the determination of Pb, Cd, Cu and Zn in sea-water is reported. Differential pulse anodic stripping voltammetry was found to be slightly more sensitive than the a.c. technique, but the effect of the charging current could be more effectively eliminated by the latter, especially in the determination of zinc(II) and copper(II). The detection limits for both techniques were found to be about 10^–10-10^–8 M for all four elements. The precision, expressed as relative standard deviation, was of the order of 2–5% for the fundamental harmonic a.c. method and 5–8% for differential pulse voltammetry. The accuracy (expressed as recovery) was 95–105% for the former and 90–110% for the latter.     

云南丽江野生香薷籽微量元素成分分析

应用电感耦合氩等离子体原子发射光谱仪（ICP－AES），对采自云南丽江的野生香薷籽进行了微量元素成分分析，其结果为开发利用野生香薷籽提供了依据。     

巯基化合物在分析中的应用

本文评述了巯基化合物在分析中的应用。叙述了其在一般的元素分析以及接着在各种吸附剂或电极的表面制得巯基吸附剂或巯基修饰电极从而用来富集测定微量元素的进展情况，引用文献达２２０篇。     

Kinetic Study of Metals Sorption on a Resin Modified with Tetrakis(carboxyphenyl)Porphyrin

 The sorption of metal ions (e.g. Cd²⁺, Cu²⁺, Ni²⁺ and Pb²⁺) from aqueous solution on the anion exchange resin Amberlite IRA-904 modified with tetrakis(4-carboxyphenyl)porphyrin (TCPP) was studied in batch equilibrium experiments. The influence of operating variables such as initial pH and contact time between solution and the resin on the equilibrium parameters was measured. The selectivity order of investigated metal ions was evaluated as follows: Pb²⁺ > Ni²⁺ > Cu²⁺ > Cd²⁺. The matrix cations, such as Mg²⁺ and Ca²⁺, exhibit very low affinity for TCPP-modified resin. The rate uptake of the sorption procedure is predominantly controlled by film diffusion. The best retention kinetic was observed for lead where half the saturation of the TCPP-modified sorbent was achieved in less than 5 min. Author for correspondence. E-mail: kryspyrz@chem.uw.edu.pl Received November 20, 2002; accepted January 26, 2003 Published online May 5, 2003     

Volcanic Quartz Growth Zoning Identified by Cathodoluminescence and EPMA Studies

 Quartz is a common phenocryst in acidic volcanic rocks but rarely contributes to the understanding of the magmatic or eruptive processes due to its apparent chemical homogeneity. Cathodoluminescence studies indicate that volcanic quartz is strongly zoned with respect to the trace elements. The determination of this zoning can help to elucidate the crystallisation history of the magmatic rock. Polished thin sections from rhyolitic and dacitic volcanic rocks were examined by cathodoluminescence mounted on an optical microscope and analysed by electron probe microanalysis. X-ray mapping of the trace elements incorporated in the zoned quartz was also performed. The interpretation of the data obtained from these different analytical methods provides useful information on the chemical zoning of single crystals and therefore on the chemico-physical conditions of the melt from which the quartz crystallised. Quartz from dacitic rock shows a complex cathodoluminescence oscillatory zoning, consisting of large red-brown and blue bands concentric to a resorbed core. Quartz from rhyolite shows simpler cathodoluminescence zoning, consisting of dark to bright blue luminescent bands. The EMPA analyses and the X-ray maps combined with the cathodoluminescence images suggest a clear correlation between the concentrations of some trace element (mainly Al and Ti, acting as activators of luminescence) and the cathodoluminescence colours pattern zoning. The incorporation of these trace elements during the growth of the crystals is linked to small variations in the thermo-chemical properties of the magma such as temperature and chemical composition.     

微波消化-ICP-MS法测定尿样中15种金属元素

采用微波消化-电感耦合等离子体质谱法测定尿样中的15种金属元素，方法回收率81％-107％，相对标准偏差为1．14％-6．71％，方法具有快速、简便、灵敏、准确的优点，对探索微量元素与健康的关系具有十分重要的意义。     

THE GLOBAL BIOSTRATIGRAPHICAL CORRELATION OF THE MEISHUCUNIAN STAGE AND THE PRECAMBRIAN-CAMBRIAN BOUNDARY

The Meishucunian Stage is rich in fossils and is characterized by their distinct evolutionsequence, so based on the established zonation of small shelly fossils, the sequence of tracefossils and the stratotype point (China "B", the dividing point between Units 6 and 7 or be-tween fossil zones Ⅰ and Ⅱ), the Meishucun section is more widely applicable to both region-al and intercontinental correlations. In this respect, the stage is well suited for both thecarbonate and the clastic-rock sedimentary regions. The Meishucunian small shelly fossil assem-blages are correlated with those found in Siberia of U.S.S.R., Mongolia, Central England,South Australia and Northwestern Canada. The Meishucunian trace fossil sequence can alsobe broadly correlated with that in the Russian Platform of U.S.S.R., Northwest Europe,Great Britain, Spain, Australia, the Western United States and Southeastern Canada.     

A comparative study of trace enrichment of chlorophenols in water by extraction with C6 and C8 alkanes and by C18 reversed-phase adsorption

The efficiency, reproducibility and sensitivity ofn-hexane and iso-octane extraction and of C₁₈ reversed-phase adsorption for accumulation of 4-chloro-, 2,4-dichloro-, 2,4,5- and 2,4,6-trichloro-, 2,3,4,6-tetrachloro- and pentachlorophenol from aqueous solutions were compared. In extraction procedures the acetyl and pentafluorobenzoyl derivatives of chlorophenols were extracted from water. In adsorption procedure chlorophenols adsorbed on a Sep-Pak C₁₈ cartridge were eluted with acetone and after that derivatized analogously.All three procedures were found to be applicable for an efficient trace enrichment of chlorophenols in water, the proper choice being dependent on the required sensitivity of the analysis. Lower detection limits of single compounds at 10 ng·1^–1 levels were achieved by adsorption procedure owing to the more uniform and for most chlorophenols higher adsorption than extraction recoveries as well as owing to the possibility of treating larger volumes of water samples. The extraction procedure could be successfully applied to the concentrations of chlorophenols in water 1g·1^–1.Owing to its higher efficiency and better sensitivity the C₁₈ reversed-phase adsorption procedure was chosen as the more suitable one for the determination of chlorophenol levels in surface, ground and drinking waters. The conversion of chlorophenols accumulated from a water sample parallel to both acetyl and pentafluorobenzoyl derivatives and the analysis of both types of derivatives on two basically different gas Chromatographic columns were recommended for a more reliable identification and quantitation of the compounds analyzed.     

7种补益中药微量元素的含量及溶出率测定

用原子吸收光谱法测定了7种补益中药中锌，铜，锰，铁，钙和镁含量及溶出率。结果显示，这6种元素的含量普遍较高，溶出率多数在80％以下，但在不同的中药中有一定的差异。