环境与生物体系中铝形态分析技术的新进展

铝的形态分析是研究环境和生物体系中铝的毒性、生物有效性和传输机理的关键。从IUPAC2000，72，1453和Analyst2001，126(2)对元素形态概念的最新定义，在过去20年来，形态分析都是依据操作手段来进行“组形态”(group species)分析。然而，随着近5年来分析技术的发展，对铝的形态分析逐步达到了“单形态”(individual species)分析的水平。从以下两个方面对该领域的最新进展进行了评述，即：(1)组形态分析(fractionation)：离子交换、电化学分析和流动注射；(2)单形态分析(speciation)：联用技术、核磁共振和计算机拟合。     

Chromium speciation in liquid matrices: a survey of the literature

A thorough review of the literature published (1983 - March 1999) on chromium speciation in liquid samples is presented, and analytical techniques used in the 404 articles are summarized. The discussion focuses on atomic spectrometric techniques, which are mainly employed for chromium speciation in liquid matrices (134 articles). Details on the type of pretreatment, species, samples, techniques and analytical features of the methodologies proposed are given.     

Applications of nuclear analytical techniques in environmental research. Plenary lecture.

Among nuclear analytical techniques, neutron activation analysis (NAA) is particularly useful for environmental studies. It affords low detection limits for many elements, high specificity and few sources of systematic error, which means that high accuracy is attainable. Neutron activation analysis is particularly useful for trace and ultra-trace analysis of environmental samples (water, soils, rocks and biological material). In trace element work associated with pollution, instrumental NAA is a powerful technique for multi-element surveys, in particular when combined with other spectroscopic techniques. Nuclear techniques, as with most analytical techniques, cannot be used to distinguish between different physico-chemical forms of an element per se. When used in combination with appropriate separation techniques, however, nuclear techniques can provide valuable information about trace element speciation in environmental and biological systems. From dynamic tracer experiments, i.e., addition of chemically well defined labelled compounds to environmental systems, valuable information can be obtained on the distribution of species and on microchemical processes influencing the physico-chemical forms. In these laboratories, speciation studies on trace elements in natural waters have been carried out by using instrumental NAA in combination with physical separation techniques, such as dialysis and ultrafiltration, in situ and in the laboratory. Dynamic radiotracer experiments have provided important information about processes influencing the speciation of trace elements in aquatic systems. Sequential extraction techniques have proved to be useful in studies on sediments and soils when combined with NAA. Sequential extractions also provide significant information about the physico-chemical behaviour of radionuclides supplied to natural soils from the Chernobyl accident.     

Analytical methodologies for aluminium speciation in environmental and biological samples--a review

It is recognized that aluminium (Al) is a potential environmental hazard. Acidic deposition has been linked to increased Al concentrations in natural waters. Elevated levels of Al might have serious consequences for biological communities. Of particular interest is the speciation of Al in aquatic environments, because Al toxicity depends on its forms and concentrations. In this paper, advances in analytical methodologies for Al speciation in environmental and biological samples during the past five years are reviewed. Concerns about the specific problems of Al speciation and highlights of some important methods are elucidated in sections devoted to hybrid techniques (HPLC or FPLC coupled with ET-AAS, ICP-AES, or ICP-MS), flow-injection analysis (FIA), nuclear magnetic resonance (27Al NMR), electrochemical analysis, and computer simulation. More than 130 references are cited.     

Trace element analytical speciation in biological systems: importance,challenges and trends

Speciation of trace elements is a relatively new field and it was in toxicology that the relationship between the chemical form of a metal and its harmful effects was first recognized. The present need for chemical speciation information in biochemistry bioinorganic and clinical chemistry is documented in an attempt to justify the present demand for innovative chemical speciation strategies and analytical technologies.The challenge and complexity of speciation is stressed and three different categories of analytical speciation of increasing analytical difficulty are proposed. Analytical strategies developed so far to try to tackle speciation problems (computational approaches, direct species-specific and hybrid techniques) are reviewed and critically assessed for biological materials. It is indisputable these days that in most cases of real-life analytical speciation we have to resort to the development and use of hybrid techniques combining an adequate separation technique for the species physical separation and an element specific detector such as those based in atomic spectrometry. Examples of such strategies, as developed mainly in the author's laboratory and including chromatographic and non-chromatographic type hybrid strategies coupled to flame, plasma and electrothermal vaporization atomic detectors, are discussed in more detail.Finally, in light of the latest trends observed in this new field, the author attempts to cast a forward look into the foreseeable future of analytical speciation research in biological and biomedical sciences. The urgent plea for quality assurance in non-routine analysis and the concept of using complementary analytical techniques and definitive methods to attack the complexity of chemical speciation in biological systems are particularly highlighted.     

Trends in speciation analysis of vanadium in environmental samples and biological fluids--a review

A comprehensive review is presented addressing recent trends in the speciation and determination of vanadium in environmental and biological sample matrices, including important analytical aspects such as sample clean up, pre-concentration and method development. Methodology based on both separation and spectroscopic techniques for the determination of vanadium speciation is discussed. A brief outline of analytical principles, together with an overview of the recent developments and applications of vanadium speciation determination is included. The newer methods for detecting metal ions including hyphenated spectroscopic techniques and sample preparation schemes are also discussed.     

Analytical methodologies for chromium speciation in solid matrices: a survey of literature

The analytical literature about chromium speciation in solid samples has been surveyed. From 451 articles published on the speciation of chromium from 1983 to 1997, the methodologies to do speciation in solids after sample pretreatment are discussed, through consideration of the types of samples and their dissolution, the analytical techniques employed for chromium measurement, and the figures of merit of the 86 papers reported in the Analytical Abstracts data base.     

Analytical methodologies for aluminium speciation in environmental and biological samples – a review

It is recognized that aluminium (Al) is a potential environmental hazard. Acidic deposition has been linked to increased Al concentrations in natural waters. Elevated levels of Al might have serious consequences for biological communities. Of particular interest is the speciation of Al in aquatic environments, because Al toxicity depends on its forms and concentrations. In this paper, advances in analytical methodologies for Al speciation in environmental and biological samples during the past five years are reviewed. Concerns about the specific problems of Al speciation and highlights of some important methods are elucidated in sections devoted to hybrid techniques (HPLC or FPLC coupled with ET–AAS, ICP– AES, or ICP–MS), flow-injection analysis (FIA), nuclear magnetic resonance (²⁷Al NMR), electrochemical analysis, and computer simulation. More than 130 references are cited.     

Analytical methodologies for chromium speciation in solid matrices: a survey of literature

The analytical literature about chromium speciation in solid samples has been surveyed. From 451 articles published on the speciation of chromium from 1983 to 1997, the methodologies to do speciation in solids after sample pretreatment are discussed, through consideration of the types of samples and their dissolution, the analytical techniques employed for chromium measurement, and the figures of merit of the 86 papers reported in the Analytical Abstracts data base. Received: 6 February 1998 / Revised: 6 March 1998 / Accepted: 7 March 1998     

土壤中砷形态分析研究进展

本文评述了近年来国内外土壤中砷形态分析的主要研究方法,包括联用分析法、分级提取法和同步辐射X-射线线吸收光谱法。联用分析法包括气相色谱联用法、毛细管电泳联用法和高效液相色谱联用法。重点介绍了目前应用范围较广的高效液相色谱-等离子体质谱(HPLC-ICP-MS)联用法和高效液相色谱-氢化物发生-原子荧光光谱(HPLC-HG-AFS)联用法。同步辐射X-射线线吸收光谱法近几年发展迅速,是最具发展潜力的形态分析方法。     

Modern trends in the speciation of selenium by hyphenated techniques

The complexity of selenium speciation in the environment and in living organisms results in broad analytical challenges. The importance of the selective determination of the particular species of this element, to understand its metabolism and biological significance in clinical chemistry, biology, toxicology, and nutrition, calls for state-of-the-art analytical techniques. In this paper hyphenated techniques are evaluated with particular emphasis on interfaced separation with element-selective detection and identification of the selenium compounds detected.     

Copper and nickel speciation in mine effluents by combination of two independent techniques

To control potentially toxic metals in water resources it is necessary to know metal speciation and changes in the metal speciation that occur after aqueous effluents containing metals are discharged into freshwaters. This work explores the speciation of nickel and copper in metal-mining aqueous effluents. Diffusive gradients in thin films (DGT) technique and competing ligand exchange (CLE) method have been applied to determine the speciation of nickel and copper. The results of this investigation demonstrate that combination of two analytical techniques having complementary analytical capabilities can provide a better physicochemical picture of metal speciation than either one of the analytical technique can do alone. The combined use of these techniques revealed that copper formed labile complexes having slow diffusion coefficient along with the presence of small labile copper complexes. Nickel-dissolved organic complexes (DOC) complexes in the aqueous effluent have been found to have fast diffusion coefficient. The results are likely to have environmental significance for providing a link between the metal species in mine aqueous effluent and their bioavailability by determining the characteristics of copper and nickel complexes in metal-mine aqueous effluents. This knowledge is expected to promote a better understanding of the lability of DOC complexes of copper and nickel in mining effluents.     

Conclusions of the workshop

The development of analytical techniques for the determination of chemical species has been one of the fastest growing features of the 90's in analytical chemistry. The need for good quality control of these determinations has led the Measurements and Testing Programme (BCR) to organize several series of interlaboratory studies in the field of speciation analysis over the last five years. The state of the art of speciation analysis was discussed at a first workshop in 1990 (Arcachon, F) and, at this stage, it was deemed necessary to discuss the progress achieved and the trends which should be developed in the near future. A workshop on Trends in Speciation Analysis was therefore held in Rome in February 1994, which allowed recommendations to be made based on round-table discussions. This paper gives a summary of these recommendations in the field of inorganic speciation. Projects currently undertaken in the field of inorganic speciation within the Measurements and Testing Programme are also described. An outline of the programme along with the panel of experts participating in this workshop is given in the appendix.     

Conclusions of the workshop

The development of analytical techniques for the determination of chemical species has been one of the fastest growing features of the 90's in analytical chemistry. The need for good quality control of these determinations has led the Measurements and Testing Programme (BCR) to organize several series of interlaboratory studies in the field of speciation analysis over the last five years. The state of the art of speciation analysis was discussed at a first workshop in 1990 (Arcachon, F) and, at this stage, it was deemed necessary to discuss the progress achieved and the trends which should be developed in the near future. A workshop on Trends in Speciation Analysis was therefore held in Rome in February 1994, which allowed recommendations to be made based on round-table discussions. This paper gives a summary of these recommendations in the field of inorganic speciation. Projects currently undertaken in the field of inorganic speciation within the Measurements and Testing Programme are also described. An outline of the programme along with the panel of experts participating in this workshop is given in the appendix.     

Speciation analysis of heavy metals in natural waters: a review.

Metal speciation in natural waters is of increasing interest and importance because toxicity, bioavailability, environmental mobility, biogeochemical behavior, and potential risk in general are strongly dependent on the chemical species of metals. This paper provides an overview of the need for speciation of heavy metals in natural waters, the chemical and toxicological aspects of speciation, and the analytical procedures for separation and the different techniques for final determination that are used today. The trends and developments of speciation are also discussed. Finally, the case of chromium (Cr) was selected for a detailed presentation because the speciation of this metal has attracted a great deal of interest in view of the toxic properties of Cr(VI).     

Inductively coupled plasma-mass spectrometry for the determination of elements and elemental species in food: a review

Inductively coupled plasma-mass spectrometry (ICP-MS) has definitely emerged as a powerful technique for total element determination and as a sensitive and selective detector in hyphenated methods for speciation analyses of elements in foods. In this review, the analytical challenges of elemental analysis of food and agricultural matrixes are discussed and several applications are examined. Selected examples illustrate the analytical approaches being used so far to address specific issues in various areas of food and nutrition research. The applications discussed include studies on dietary intake, element metabolism in man, transfer of elements through the food chain, effects of food processing and domestic preparation, and authenticity and origin assessment. The use of ICP-MS in the field of analytical quality assurance, food control, evaluation of food contact materials, and radionuclide contamination is also examined. Finally, the hyphenated techniques with ICP-MS detection used for elemental speciation in food are reviewed, and an overview of the main applications currently in the literature is presented. Throughout, recent trends and analytical developments likely to have a major impact on food-related areas are highlighted.     

Analytical methods for the determination of arsenosugars—A review of recent trends and developments

Arsenic-containing carbohydrates, generally termed arsenosugars, have been the subject of increasing analytical interest in arsenic speciation analysis. The present review gives an overview concerning achievements and trends in the field of instrumental analysis of arsenosugars. The typical experimental approaches for sample pre-treatment, extraction, separation and detection are discussed. Current possibilities and limitations of modern instrumental techniques are pointed out.     

生物样品中硒的测定方法及形态分析研究进展

硒的毒性和营养功能不仅与其总量有关,而且与其存在的化学形态有关。因此,硒的测定及形态分析对于了解不同形态的硒化物在生物体和环境中的迁移转化规律具有重要意义。文章综述了生物样品中硒的测定分析方法以及形态分析研究进展。     

Arsenic speciation analysis

Nearly two dozen arsenic species are present in the environmental and biological systems. Differences in their toxicity, biochemical and environmental behaviors require the determination of these individual arsenic species. Considerable analytical progresses have been made toward arsenic speciation analysis over the last decade. Hyphenated techniques involving a highly efficient separation and a highly sensitive detection have become the techniques of choice. Methods based on high-performance liquid chromatography separation with inductively coupled plasma mass spectrometry, hydride generation atomic spectrometry, and electrospray mass spectrometry detection have been shown most useful for arsenic speciation in environmental and biological matrices. These hyphenated techniques have resulted in the determination of new arsenic species, contributing to a better understanding of arsenic metabolism and biogeochemical cycling. Methods for extracting arsenic species from solid samples and for stabilizing arsenic species in solutions are required for obtaining reliable arsenic speciation information.     

The chemical speciation of aluminium in human serum

Chemical speciation of aluminium in the low molecular mass (LMM) and high molecular mass (HMM) fractions of human serum is discussed. A critical review of the literature on different analytical procedures described for the speciation of aluminium in human serum samples is presented here. The methodologies, the experimental and instrumental requirements and the ability of the reported analytical procedures for identification of HMM and LMM aluminium species in human serum are examined in detail. Non-chromatographic separations coupled to electrothermal atomic absorption spectrometry for aluminium detection are compared with chromatographic techniques (size exclusion chromatography, anion exchange chromatography and fast protein liquid chromatography) coupled to ETAAS or inductively coupled plasma mass spectrometry (ICP-MS) detection for Al-HMM species investigations. Studies and techniques reported for Al-LMM compounds are also summarised, both for healthy volunteers and dialysis patients. On the basis of the knowledge obtained from the application of the developed analytical procedures to real serum analysis, it has been demonstrated that most of Al in human serum is bound to Al-transferrin, while the LMM-Al fraction (10-20% of total Al) mainly contains Al-citrate, Al-phosphate and ternary Al-citrate-phosphate complexes.