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1.
应用卤族元素的ΔG/FZ图(自由能氧化态图)概括地总结了卤族元素含氧酸及其盐在水溶液体系中的氧化还原性的规律;讨论了卤素含氧酸及其盐的氧化性强弱与溶液酸碱性、与元素在周期表中的位置的关系;说明了卤素含氧酸的还原产物形态。  相似文献   

2.
毛细管电泳用于形态分析   总被引:9,自引:0,他引:9  
一种元素的生物可给性、环境行为和迁移性在很大程度上取决于它的形态。如不同的键合形式或氧化态,因此,作为元素物种鉴别和含量测定的形态分析变得越来越重要。毛细管电泳作为一种分离分析技术有许多优点可以满足形态分析的要求。本文从样品的预处理、毛细管电泳的修饰、进样方式、分离模式和检测等几个方面评述了毛细管电泳在形态分析中的应用。  相似文献   

3.
《色谱》2005,23(5):503-503
元素形态分析是21世纪分析化学中发展最快的研究领域之一.而各种色谱(包括电泳)与原子光谱/质谱联用技术则是元素形态分析最有效的手段。本书详细介绍了自20世纪90年代以来联用技术及元素形态分析的研究成果及发展趋势。内容包括元素形态分析中的试样前处理技术、非色谱原子光谱/质谱联用技术、色谱(包括气相色谱、液相色谱、毛细管电泳)、原子光谱/质谱联用技术以及环境和生物体系中元素形态分析等。  相似文献   

4.
新疆茜草中铜锰铁锌钙镁的形态分析   总被引:1,自引:0,他引:1  
结合新疆茜草的药用价值,用煎煮法对新疆茜草中的Cu、Mn、Fe、Zn、Ca和Mg进行了含量和形态分析.用0.45 μm滤膜分离提取液中的可溶态与悬浮态,用D101大孔吸附树脂分离可溶态中的有机态与无机态.对水煎渣依次用丙酮和盐酸提取有机态和无机态,用原子吸收光谱(AAS)法对六种元素的各个形态进行测定.结果表明:新疆茜草中各个元素的提取率在31.5%~45.2%之间,六种微量元素的相对标准偏差在0.11%~1.23%,回收率在92.5%~104.7%.  相似文献   

5.
作为新型材料的典型代表,纳米材料具有粒径小、比表面积大、表面原子活性高等优点,已成为一类极具潜力的固相萃取材料,在痕量元素及其形态分析领域得到了广泛的应用.本文对不同类型纳米材料与原子光/质谱相结合在痕量元素及其形态分析中的应用现状进行了评述,包括零维纳米材料(如纳米球、富勒烯、量子点等)、一维纳米材料(如碳纳米管、纳米棒、纳米线等)、二维纳米材料(如纳米纤维、石墨烯/氧化石墨烯、层状双氢氧化物等)及三维纳米材料(如三维碳材料、纳米海绵、树枝状大分子等).为了改善其选择性、拓宽其在不同实际样品中的应用潜力、或进一步提高其吸附容量,一些新型的纳米材料包括离子印迹材料、限制性进入材料、金属有机框架材料等也被用于环境及生物样品中痕量元素及其形态的分析,推动了其在该研究领域的进一步发展.  相似文献   

6.
电化学分析方法在元素形态分析中的应用   总被引:10,自引:0,他引:10  
孙微  王磊  李一峻  何锡文 《分析化学》2004,32(4):541-545
对电分析方法在常见元素形态分析中的应用进行了评述,并展望了电分析技术在形态分析中的应用前景。引用文献83篇。  相似文献   

7.
为科学指导中药安全性标准的建立和合理评价中药的安全性和有效性,通过比较中国、美国及欧洲等药典电感耦合等离子体质谱法[ICP-MS,包括高效液相色谱(HPLC)-ICP-MS]通则方法及技术体系,综述了药典中ICP-MS的方法体系及在中药(动物药、植物药或矿物药)中重金属元素及有害元素、元素形态或价态检测中的技术规范和应用范围;通过相关文献整理,综述了ICP-MS在中药无机成分安全性评价及风险评估、无机元素谱及质量评价和有害元素形态及价态等方面的应用进展,并对ICP-MS新技术和方法在中药研究的应用前景进行了展望(引用文献57篇)。  相似文献   

8.
应用改进的BCR法对大气微颗粒物(PM2.5)进行分析,用超声法代替原来的机械振荡法,对所采得的微颗粒物样品中6种重金属元素(铜、锌、铅、镉、镍、铬)的4种化学形态(酸可交换态F1,可还原态F2,可氧化态F3及残渣态F4)进行分别提取,所得各形态溶液中的金属元素含量用电感耦合等离子体质谱法测定。结果表明:超声提取法的提取时间仅为30min(对F1及F2)和20min(对F3),而原方法需16h;而且超声提取的效率较高,是原方法的89.5%~133%;6种元素的化学形态测定结果的相对标准偏差(n=8)均小于25%。此外,样品中的元素形态总量(ng·m-3)与元素全量(ng·m-3)之间的偏差在-30.7%~-11.5%之间。  相似文献   

9.
用氩离子溅射-XPS纵深分析方法对通道电子倍增器内二次电子发射材料的元素组成和原子价态进行了分析,结果表明该材料中的主要元素为Pb,Bi,Ba,Si和O,其中Pb和Bi都以混合价态存在,它们分别是Pb^2 和Pb^0;Bi^3 和Bi^0.  相似文献   

10.
黄芪中微量元素的形态分析   总被引:16,自引:0,他引:16  
按照传统煎煮法对中药黄芪中铜、锌、铁、镁、钙和铬6种元素进行提取;用微孔滤膜分离提取液中的可溶态与悬浮态;利用大孔吸附树脂柱对可溶态中的有机态与无机态进行分离;采用火焰原子吸收光谱法对各种形态中的6种元素进行测定。结果显示:黄芪中6种元素的总提取率在44.0%~74.4%,浸留比在79·4%~293.8%,悬浮态颗粒吸附率在10%左右,可溶态中铬的有机态与无机态的比例为114.6%,铜、锌、铁、镁、钙的有机态与无机态的比例在3.7%~43.5%。该法对各元素的加标回收率在96.8%~103.1%;相对标准偏差小于1.5%。  相似文献   

11.
螯合吸附分离功能纤维的研究进展   总被引:5,自引:0,他引:5  
螯合纤堆是一类能与金属离子形成多配位络合物的纤堆状吸附功能材料,是近年来发展起来的一种新型离子交换纤堆,具有吸附选择性高、易洗脱、容易再生等优点。综述了近年来螯合纤堆的制备方法及种类,对其螯合机理进行了探讨,概括了该纤堆的应用范围并指出了其应用前景。  相似文献   

12.
Trace element speciation has recently become one of the most important problems in water analysis. Proper combination of preconcentration techniques with instrumental determination methods is essential to speciation analysis, because sensitivity and selectivity of direct determination methods are generally lacking. The present paper describes such preconcentration techniques as filtration, centrifugation, flotation and sorption, which have been developed in the author's laboratory for the speciation of heavy metals in river and pond waters by electron microscopy, X-ray microanalysis and chemical analysis. The application of freeze concentration to the speciation of silica in high-purity waters is also discussed.  相似文献   

13.
分离富集技术在形态分析中应用进展   总被引:6,自引:0,他引:6  
对十年来分离富集技术在形态分析中应用进展进行了评述,引用1991~2001年文献67篇。  相似文献   

14.
《Analytical letters》2012,45(7):1031-1043
Nanoparticles, notable for their small size, high surface area to volume ratios, and strong adsorption capacity, have been the subject of great interest in analytical chemistry. Over the past decade, nanoparticles have been widely used as adsorbents for elemental speciation. Elemental ions or chelates may interact with nanoparticles by van der Waals forces, hydrogen bonds, and hydrophobic interactions. Various types of nanoparticles used for elemental speciation, including magnetic nanoparticles, carbon nanotubes, metallic oxide nanoparticles, nanostructured mixed oxides, and ion imprinted polymer nanoparticles, are reviewed. Future trends and development in this research area are discussed.  相似文献   

15.
周瑛  叶丽  竹鑫平 《化学进展》2007,19(6):982-995
食品中含有与人体健康密切相关的多种微量元素,微量元素的毒性和生物有效性取决于它们的化学形态。食品中的微量元素形态分析及其生物有效性研究对食品安全控制与营养评价具有至关重要的意义。本文扼要介绍了高效液相色谱与电感耦合等离子质谱(HPLC-ICP-MS)联用情况,该技术以不同的色谱分离柱完成各种分析物的分离,具有高灵敏度、高选择性、线性范围宽、检测限低、多元素同时检测等特点,在微量元素形态分析中占有重要的地位。综述了HPLC-ICP-MS在食品微量元素形态分析及其生物有效性研究中的应用,重点介绍了富硒酵母、蒜类植物、富硒营养保健品等食品中硒形态和海产品、农产品等食品中砷形态的研究,以及其它多种微量元素的形态分析和这些微量元素在生物体内的代谢。  相似文献   

16.
Trace metals play an important role in the regulation of primary productivity and phytoplankton community composition. Metal species directly affects the biogeochemical cycling processes, transport, fate, bioavailability and toxicity of trace metals. Therefore, developing powerful methods for metal speciation analysis is very useful for research in a range of fields, including chemical and environmental analysis. Voltammetric methods, such as anodic stripping voltammetry (ASV) and competing ligand exchange-adsorptive cathodic stripping voltammetry (CLE-AdCSV), have been widely adopted for speciation analysis of metals in different natural aquatic systems. This paper provides an overview of the theory of voltammetric methods and their application for metal speciation analysis in natural waters, with a particular focus on current voltammetric methods for the discrimination of labile/inert fractions, redox species and covalently bound species. Speciation analysis of typical trace metals in natural waters including Fe, Cu, Zn, Cd, and Pb are presented and discussed in detail, with future perspectives for metal speciation analysis using voltammetric methods also discussed. This review can elaborate the particular knowledge of theory, merits, application and future challenge of voltammetric methods for speciation analysis of trace metals in natural waters.  相似文献   

17.
《中国化学快报》2021,32(9):2629-2636
The analysis of endogenous glycoproteins and glycopeptides in human body fluids is of great importance for screening and discovering disease biomarkers with clinical significance. However, the presence of interfering substances makes the direct quantitative detection of low-abundance glycoproteins and glycopeptides in human body fluids one of the great challenges in analytical chemistry. Magnetic solid phase extraction (MSPE) has the advantages of easy preparation, low cost and good magnetic responsiveness. Magnetic adsorbents are the core of MSPE technology, and magnetic adsorbents based on different functional materials are widely used in the quantitative analysis of glycoproteins and glycopeptides in human body fluids, making it possible to analyze glycoproteins and glycopeptides with low abundance as well as multiple types, which provides a technical platform for screening and evaluating glycoproteins and glycopeptides in body fluids as disease biomarkers. In this paper, we focus on the recent advances in the application of MSPE technology and magnetic adsorbents for the separation and enrichment of glycoproteins and glycopeptides in human body fluids, and the future trends and application prospects in this field are also presented.  相似文献   

18.
A sorption–atomic absorption technique with dynamic preconcentration on DETATA adsorbents in a microcolumn crucible followed by the direct atomization of a solid matrix (concentrate + suspended matter) was used to determine the total dissolved and suspended Cd, Pb, and Tl (Eldis+ Elsusp) in natural waters. The detection limits were 1–3 ng/L for Cd and 5–30 ng/L for Pb and Tl. The results of the sorption–filtration atomic absorption determination of the total dissolved and suspended elements can provide extra information for the speciation analysis of waters.  相似文献   

19.
Timerbaev AR 《Talanta》2000,52(4):573-606
An overview of recent developments in the application of capillary electrophoresis to simultaneous separation and determination of different chemical forms of an inorganic element is presented, with particular emphasis placed on metal speciation analysis. Examples of species analysis are addressed, covering metal ions in different oxidation states, metal complexes with inorganic and organic ligands, metalloid oxoanions, organometallic compounds, ionic non-metal species, etc. The speciation performance of capillary electrophoresis is illustrated by a number of practically relevant applications. The method's strengths and current limitations with regard to chemical speciation studies are critically discussed.  相似文献   

20.
土壤中砷形态分析研究进展   总被引:1,自引:0,他引:1  
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。  相似文献   

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