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1.
The determination of trace metals in solid samples has traditionally been performed by acid digestion and subsequent measurement by a suitable instrumental technique. This dissolution step is time-consuming and it shows important drawbacks. For these reasons, in the past years many efforts have been focused on the direct analysis of solid samples. Among the developed methodologies, slurry sampling-electrothermal atomic absorption spectrometry combines the significant advantages of the solid and liquid sampling methods, and it can be already considered as a mature technique, that is widely utilized for metal determination in both organic and inorganic matrices, even for routine analysis. Accordingly, this work gives a retrospective view of the progresses of this technique during the past decade (1990-2000).  相似文献   

2.
    
Summary A new technique for the characterization of solid materials is proposed, consisting in the transfer of extremely small amounts of the solid substance by abrasion onto the surface of a suitable solid electrode. The abrased material is electrochemically stripped off and this process is traced with a voltammetric method, e.g., differential pulse voltammetry. The method allows the easy and fast identification of solid materials, avoids the dissolution of the sample and hence reveals information about the structure of the solid material, thus allowing electrochemical phase analysis. The proposed technique of abrasive stripping analysis is applicable to a wide range of inorganic and organic substances.
Identifizierung von Festkörpern mit einer neuen elektrochemischen Technik — der Voltammetrie mit vorangehender mechanischer übertragung des Depolarisators auf die ElektrodenoberflÄche
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3.
固相萃取   总被引:82,自引:0,他引:82  
张海霞  朱彭龄 《分析化学》2000,28(9):1172-1180
近10多年来,固相萃取作为试样预处理技术得到迅速的发展。评述了该技术的特点、装置、方法的建立,应用和前景。文中强调固相萃取在环境分析、药物分析等方面有广泛的应用前景,并总结了近年来固相萃取在药物分析中的应用。  相似文献   

4.
用横向光热偏转技术测量双硫腙固体试样的光谱特性及H2Dz的浓度与横向光热偏转辐度之间的关系,检测限可达ng量级,为固体不透明材料的微量特性分析提供了一个简便的方法。  相似文献   

5.
Pesticides, widely applied in agriculture, can produce a variety of transformation products and their continuous use causes deleterious effects to ecosystem. Efficient and sensitive analytical techniques for enrichment and analysis of pesticides samples are highly required. Compared with other extraction methods, solid‐phase micro extraction is a solvent free, cost effective, robust, versatile, and high throughput sample preparation technique, especially for the analysis of pesticides from complicated matrices. Coupling of solid‐phase micro extraction with gas chromatography and mass spectrometry and liquid chromatography–mass spectrometry has been extensively applied in pesticide analysis. On the other hand, in recent years, combination of fast separation using solid‐phase micro extraction and rapid detection using ambient mass spectrometry is providing highly efficient pesticide screening. This article summarizes the applications of solid‐phase micro extraction coupled to mass spectrometry for pesticides analysis.  相似文献   

6.
The kinetics of nickel reduction and morphological changes in Ni–10Sc1CeSZ composite anodes in intermediate-temperature solid oxide fuel cells (SOFC) are studied using the Raman spectroscopy technique with the help of application of optically transparent single crystal solid electrolyte membranes and also the thermogravimetric analysis technique. It is shown that the first reduction cycle differs considerably from all the further ones, which is related to morphological changes of nickel grains occurring during the first reduction cycle. A general scheme of occurrence of the process is suggested in studies of model cells using the Raman spectroscopy technique and also in the case of thermogravimetric analysis of powders; it explains the causes for significant differences between the total duration of the process as measured using different techniques. The results of the work can be used for optimization of the mode of initial reduction of the anodic SOFC electrode.  相似文献   

7.
微电极电位溶出法研究进展   总被引:2,自引:0,他引:2  
本文介绍用于电位溶出分析(PSA)的固体微电极的种类及制作,综述了该领域研究的理论进展、技术应用及其方法的优越性,引用文献41篇  相似文献   

8.
Solid/liquid interfaces are important locations for various chemical reactions, such as electrode chemical reactions and metal corrosions. Conventional surface analytical methods, such as XPS and SEM-EDS, have been applied to solid materials after being removed from the liquid phase. These methods do not involve direct observation, although useful information is available. It is important to directly observe surface reactions on solid materials in the liquid phase in order to understand the details of these reactions. One feasible method of doing this is 3D micro-XRF analysis. The confocal 3D micro XRF method enables nondestructive x-ray elemental analysis of localized microspace. We have applied a confocal 3D micro-XRF instrument for solid/liquid interface analysis. This technique was applied for direct observation of the chemical deposition of Cu on an Fe plate and the dissolution of Fe in a CuSO4 solution.  相似文献   

9.
The recent arrival of high-resolution continuum source atomic absorption spectrometry represents a potential revolution in this field, in particular for direct analysis of complex samples. This review tries to illustrate the main advantages of this technology, paying particular attention to the development of direct solid sampling methods. Three solid sampling applications will be discussed, each one of them highlighting one of the main advantages of this technique. The review also intends to clarify some misconceptions on the true potential of the instrumentation that is currently commercially available, such as its performance for multielemental analysis.  相似文献   

10.
The mono- and di-imines of some diaminonaphthalenes were prepared using a solid solid reaction technique. Their structures were studied using elemental analysis, infrared and electronic spectra. The thermal behaviour of the obtained compounds and their solid solid preparation reactions have also been studied. The energies of activation as well as the reaction orders of those reactions were determined.  相似文献   

11.
A technique has been developed for performing headspace GC-MS analysis of volatile components of food, in which the carrier gas flow is reversed during sampling in order to overcome problems caused by the diffusion of substances not retained by the cold trap. Chromatographic profiles of volatile compounds from cheeses, obtained at room temperature, provide confirmation of the validity of the reversed flow technique, and the versatility of the system is evidenced by its successful application to both solid and liquid matrixes: the absence of any discrimination against the various components reveals its efficacy for compounds with a wide range of volatility. Addition of internal standards to the sample enables the use of the technique for quantitative analysis.  相似文献   

12.
Comparisons are made of two techniques for the trace analysis of volatile organic compound (VOC) emissions from consumer products: direct on-line sampling and analysis and on-line solid sorbent collection followed by off-line analysis. Two types of direct analyses are examined. The first consists of direct injection of emissions from a sample loaded environmental chamber into a gas chromatograph equipped with a flame ionization detector (FID) for compound identification. Direct injection of headspace collected emissions into a gas chromatograph equipped with a mass selective detector is the second direct method scrutinized. The more traditional technique of solid sorbent collection of the volatile organic emissions followed by thermal desorption (TD)/gas chromatographic (GC)/mass spectrometric (MS) analysis is compared to both direct on-line methods.  相似文献   

13.
Molecular ions include information about end groups, functional groups and molecular weight. A method for the direct detection of these in the high mass range (m/z > 1000) from poly(dimethylsiloxane) (PDMS) on a solid surface was investigated. It was found that a TOF-SIMS analysis of silver-deposited surfaces (silver deposition/TOF-SIMS) is useful for this purpose. Using the silver-deposition/TOF-SIMS method, silver-cationized quasi-molecular ions were clearly detected from PDMS on solid surfaces, and their structure and molecular weight were evaluated. In addition, their images were observed without the interference of deposited silver. By applying to the analysis of paint defects etc., it was confirmed that this technique is useful to analyze actual industrial materials. Silver-cationized ions were detected not only from PDMS, but also from other organic materials, such as lubricant additives and oils on solid surfaces. Therefore, the silver deposition/TOF-SIMS method was proved to be useful for the analysis of ultrathin substances on solid surfaces.  相似文献   

14.
辉光放电灯(GDL)作为光源被广泛应用于固体样品的直接分析中,文章综述了GDL的发展过程、类型及其在分析中的应用。  相似文献   

15.
An analysis of thermal degradation products evolved during the melt processing of organo-layered silicates (OLS) was carried out via the use of a solid phase microextraction (SPME) technique. Two commerical OLSs and one produced in-house were prepared for comparision. The solid phase microextraction technique proved to be a very effective technique for investigating the degradation of the OLS at a specific processing temperature. The results showed that most available OLSs will degrade under typical conditions required for the melt processing of many polymers, including thermoplastic polyurethanes. It is suggested that these degradation products may lead to changes in the structure and properties of the final polymer, particularly in thermoplastic polyurethanes, which seem significantly succeptable to the presence of these products. It is also suggested that many commercially available OLSs are produced in such a way that results in an excess of unbound organic modifier, giving rise to a greater quantity of degradation products. All OLSs where compared and characterised by TGA and GC-MS.  相似文献   

16.
Scanning electrochemical microscopy (SECM) has been proven to be a valuable technique for the quantitative investigation and surface analysis of a wide range of processes that occur at interfaces. In particular, there is a great deal of interest in studying the kinetics of charge transfer characteristics at the solid/liquid and liquid/liquid interface. This overview outlines recent advances and applications of SECM to the investigation of charge transfer reactions at the solid/liquid interface and liquid/liquid interface.  相似文献   

17.
固体无机样品的激光等离子体质谱分析   总被引:1,自引:0,他引:1  
激光等离子体质谱是一种新颖的质谱分析手段,具有灵敏度高,分析速度快,分析范围广,分析结果准确性高等优点。本文介绍了在自制的激光离子体源飞行时间质谱计上,有关催化剂,铝箔,活性碳,岩石等固体无机样品的质谱分析结果,显示了激光等离子体质谱的优越性与广泛的应用价值。  相似文献   

18.
Extraction of endogenous compounds and drugs and their corresponding metabolites from complex matrices, such as biofluids and solid tissues, requires adequate analytical approach facilitating qualitative and quantitative analysis. To this end, solid‐phase microextraction has been introduced as modern technology that is capable of efficient and high‐throughput extraction of compounds due to its ability to amalgamate sampling, extraction, and pre‐concentration steps, while requiring minimal use of organic solvents. The ability of solid‐phase microextraction to enable analyses on small‐volume biological samples and growing availability of biocompatible solid‐phase microextraction coatings make it a highly useful technology for variety of applications. For example, solid‐phase microextraction is particularly useful for identifying biomarkers in metabolomics studies, and it can be successfully applied in pharmaceutical and toxicological studies requiring the fast and sensitive determination of drug levels, especially those that are present at low levels in biological matrices such as plasma, urine, saliva, and hair. Moreover, solid‐phase microextraction can be directly applied in in vivo studies because this extraction technique is non‐exhaustive and its biocompatible probes offer minimal invasiveness to the analyzed system. In this article, we review recent progress in well‐established solid‐phase microextraction technique for in vitro and in vivo analyses of various metabolites and drugs in clinical, pharmaceutical, and toxicological applications.  相似文献   

19.
The technique of trace element analysis by the detection of characteristic X-rays induced by high energy proton bombardment is critically examined. A discussion of the restrictions imposed by detector resolution is made, the behavior of the cross-section for X-ray production as a function of energy and atomic number is discussed. The effect of this behavior upon analysis time is demonstrated. Background is discussed in terms of its effect on the total counting rate. The use of a silicon solid state detector to determine the overlappingK-lines of light elements andL-lines of heavy elements is shown to have severe limitations. A combination of crystal monochromators and solid state detectors is suggested as a means to circumvent some of the fundamental limitations encountered with a single detector. An experimental arrangement for the use of twenty-four crystal monochromators and two solid state detectors is shown. Work supported in part by the U.S. Atomic Energy Commission.  相似文献   

20.
A method for determining trace metals in polymers which combines flameless atomic absorption with a solid sampling technique is described. The method is applied to the analysis of iron, copper and chromium and is compared with results obtained from analysis of solutions of the polymers. Optimal conditions for achieving maximal accuracy and sensitivity are discussed. The effects of various matrix interferences and the heterogeneous distribution of trace metals in polymers are discussed.  相似文献   

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