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1.
在中国开展的中药微量元素研究证明,中药有效药成分由有机药成分和无机药成分组成,两者共生共存。从含水络合离子、天然有机金属配合物、中药有机药成分-微量元素配合物,以及中药有机药成分-微量元素复合物四个方面,论述了微量元素在中药有效药成分中的核心地位和核心作用。  相似文献   

2.
The compositional changes of inorganic elements on freshwater leaching of 35 species of Chinese algae were studied by the determination of the element contents in marine algae using instrumental neutron activation analysis. It was found that alkali metals and chlorine mainly exist as ions in algae, in which, water-soluble K and Na exist as chlorides. While, other elements exist as the states of both ions and organic combination in which the water leaching ratios of alkaline earth metals are the lowest. The combination of trace elements with various organic macromolecules inSargassum kjellmanianum was also studied using neutron activation analysis combined with chemical and biochemical separation techniques. The results indicate that the concentration of many trace elements, such as Zn, Fe, Sc, Th are earths in protein are quite high, and some trace elements can also be combined by pigment and polyphenol. Alkaline earth metal mainly bind with alginic acid inSargassum kjellmanianum.  相似文献   

3.
The No. 2 coal seam of the Witbank basin, South Africa, has a well defined geological layering that extends laterally over most of the basin. Palaeoenvironmental studies indicate that the No. 2 seam accumulated in two distinct depositional environments: glaciofluvial channels and regions represented by transgressive marine sediments. A systematically selected suite of samples was collected to study the distribution of trace elements both laterally and vertically across the No. 2 seam. A total of 121 coal samples were analysed for 15 trace elements by instrumental neutron activation analysis. Detailed trace element profiles across the No. 2 seam indicate that trace elements associated with the inorganic minerals in coal reflect vertical changes in the clastic source areas, environments of precipitation and accumulation or intrusive mineralisation in the post-peat swamp phases of the No. 2 seam. Trace elements associated with the organic matter in coal relate to changes in the palaeoenvironment or possible plant associations. Variation in the concentration of Br across the Witbank basin reflect regional changes in the depositional environment. In turn the chemical nature of the depositional environment strongly effects the distribution of some trace elements among maceral groups. on indefinite secondment to the NPRU  相似文献   

4.
对太原西山矿区8号煤层的肥、焦、瘦、贫等不同烟煤的镜煤组分进行了酸洗脱灰处理,并同时对这些酸洗后的样品进行了红外分峰处理和微量元素含量的测定,发现随着煤的变质程度加深,某些有机基团与某些微量元素呈正相关关系,并因其正相关系数很高而结合的可能性很大;有的呈负相关关系;也有的和微量元素部分呈正相关变化部分则呈负相关变化。因此,将煤的有机基团分为三类:微量元素亲和性有机基团、微量元素憎厌性有机基团和对微量元素既无亲和性也无憎厌性的中性有机基团。微量元素和煤的有机基团之间相互选择性很强。但无论表现为典型的亲和性还是憎厌性,其亲和、憎厌程度的变化波动趋势,均遵循一个统一的变化规律——元素周期律。典型的中性有机基团,对亲石元素和亲铁亲铜元素所表现的亲和、憎厌倾向也有明显不同,有一定的规律可循。煤中不同类型的有机基团和微量元素的正负相关性,即对微量元素的亲和和憎厌性,对元素周期律的响应型式和响应程度差别也很大。  相似文献   

5.
Inductively coupled plasma mass spectrometry (ICP-MS) and laser ablation ICP-MS (LA-ICP-MS) have been applied as the most important inorganic mass spectrometric techniques having multielemental capability for the characterization of solid samples in materials science. ICP-MS is used for the sensitive determination of trace and ultratrace elements in digested solutions of solid samples or of process chemicals (ultrapure water, acids and organic solutions) for the semiconductor industry with detection limits down to sub-picogram per liter levels. Whereas ICP-MS on solid samples (e.g. high-purity ceramics) sometimes requires time-consuming sample preparation for its application in materials science, and the risk of contamination is a serious drawback, a fast, direct determination of trace elements in solid materials without any sample preparation by LA-ICP-MS is possible. The detection limits for the direct analysis of solid samples by LA-ICP-MS have been determined for many elements down to the nanogram per gram range. A deterioration of detection limits was observed for elements where interferences with polyatomic ions occur. The inherent interference problem can often be solved by applying a double-focusing sector field mass spectrometer at higher mass resolution or by collision-induced reactions of polyatomic ions with a collision gas using an ICP-MS fitted with collision cell. The main problem of LA-ICP-MS is quantification if no suitable standard reference materials with a similar matrix composition are available. The calibration problem in LA-ICP-MS can be solved using on-line solution-based calibration, and different procedures, such as external calibration and standard addition, have been discussed with respect to their application in materials science. The application of isotope dilution in solution-based calibration for trace metal determination in small amounts of noble metals has been developed as a new calibration strategy. This review discusses new analytical developments and possible applications of ICP-MS and LA-ICP-MS for the quantitative determination of trace elements and in surface analysis for materials science.  相似文献   

6.
目的通过测定8批复方木鸡颗粒中无机元素的含量,拟从无机成分的角度探讨复方木鸡颗粒的特征元素。方法采用电感耦合等离子体质谱仪(ICP-MS),以半定量分析的方式测定8批次复方木鸡颗粒无机元素的含量,建立复方木鸡颗粒无机轮廓谱,并对其差异元素中的重金属元素和人体有益元素进行全定量测定,同时,采用聚类分析和主成分分析,对其特征元素进行评价。结果构建了复方木鸡颗粒无机元素的轮廓谱,通过聚类分析和主成分分析共找到6个特征元素,包括Ca、Mg、Mn、K、Cr、Ni。结论从无机成分的角度明确了复方木颗粒的特征元素,为进一步探究复方木鸡颗粒的药效研究提供理论依据。  相似文献   

7.
采用脱矿物质、提取腐殖酸等方法结合ICP-MS对伊敏15、16煤中的32种微量元素的含量及其赋存特征进行了分析。与地壳克拉克值及中国侏罗-白垩纪煤和世界褐煤中微量元素含量相比,伊敏褐煤中微量元素没有明显富集。脱矿物质处理后,Ni明显富集,As略比原煤高,其他微量元素都低于原煤。原煤提取腐殖酸和脱矿物煤提取腐殖酸中Ni、Mo、Cd、Sn、W明显富集,这表明Ni、Mo、Cd、Sn、W和腐殖酸形成了稳定的有机态化合物。原煤提取腐殖酸残煤和脱矿物煤提取腐殖酸残煤中V、Ni、As富集,表明V、Ni、As与煤的大分子结构形成了稳定的有机态化合物。根据微量元素和灰分的相关性系数,把微量元素分为以下几类:无机富集元素Cr、U;亲无机元素Cu、Cd、In、Sn、Ga、Y、Zr、Hf、Bi、Th;偏无机元素Be、Sc、Rb、Sr、Nb、Cs、Ta、Pb;偏有机元素V、As、Tl、Ba、Se;亲有机元素Li、Co、W;有机富集元素Ni、Zn、Mo、Sb。  相似文献   

8.
9.
Fly ash has been regarded as hazardous because of its high adsorption of toxic organic and/or inorganic pollutants. Fly ash is also known to have broad distributions of different chemical and physical properties, such as size and density. In this study, fly ash emitted from a solid waste incinerator was pre-fractionated into six sub-populations by use of gravitational SPLITT fractionation (GSF). The GSF fractions were then analyzed by sedimentation field-flow fractionation (SdFFF) and ICP–AES. SdFFF analysis showed the fly ash has a broad size distribution ranging from a few nanometers up to about 50 µm. SdFFF results were confirmed by electron microscopy. Inductively coupled plasma–atomic emission spectroscopy (ICP–AES) analysis of the GSF fractions showed the fly-ash particles contain a variety of inorganic elements including Ca, Si, Mg, Fe, and Pb. The most abundant in fly ash was Ca, followed by Si then Mg. No correlations were found between trace element concentration and particle size.  相似文献   

10.
Organic or inorganic colloids play a major role in the mobilization of trace elements in soils and waters. Environmental physicochemical parameters (pH, redox potential, temperature, pressure, ionic strength, etc.) are the controlling factors of the colloidal mobilization. This study was dedicated to follow the colloid-mediated mobilization of trace elements through time at the soil/water interface by means of an experimental approach. Soil column experiments were carried out using percolating synthetic solutions. The percolated solutions were ultrafiltrated with various decreasing cutoff thresholds to separate the different colloidal phases in which the dissolved organic carbon and trace element concentrations were measured. The major results which stem from this study are the following: (i) The data can be divided into different groups of organic compounds (microbial metabolites, fulvic acids, humic acids) with regard to their respective aromaticity and molecular weight. (ii) Three groups of elements can be distinguished based on their relationships with the colloidal phases: the first one corresponds to the so-called "truly" dissolved group (Li, B, K, Na, Rb, Si, Mg, Sr, Ca, Mn, Ba, and V). The second one can be considered as an intermediate group (Cu, Cd, Co, and Ni), while the third group gathers Al, Cr, U, Mo, Pb, Ti, Th, Fe, and rare earth elements (REE) carried by the organic colloidal pool. (iii) The data demonstrate that the fulvic acids seem to be a major organic carrier phase for trace elements such as Cu, Cd, Co, and Ni. By contrast, the trace elements belonging to the so-called colloidal pool were mostly mobilized by humic acids containing iron nanoparticles. Lead, Ti, and U were mobilized by iron nanoparticles bound to these humic acids. Thus, humic substances allowed directly or indirectly a colloidal transport of many insoluble trace elements either by binding trace elements or by stabilizing a ferric carrier phase. (iv) Finally, the results demonstrated also that REE were mostly mobilized by humic substances. The REE normalized patterns showed a middle REE downward concavity. Therefore, as previously shown elsewhere humic substances are a major control of REE speciation and REE fractionation patterns as well since the humic substance/metal ratio was the key parameter controlling the REE pattern shape.  相似文献   

11.
In natural waters trace elements, especially trace metals may be present in a variety of physicochemical forms. They may be associated with forms ranging from simple ions and molecules via hydrolysis products and colloids, pseudocolloids and organic or inorganic particles. The transition between categories is gradual. The presence of species differing in size, charge and density will influence on the transport, mobility and bioavailability of the trace element in question. Fractionation techniques which do not influence the distribution patterns are therefore required for speciation purposes. In the present work dialysis in situ and large membrane (hollow fibers) ultrafiltration are used for fractionation of low molecular weight species, colloids, pseudocolloids and particles. Due to the presence of foreign components transformation processes influence the distribution patterns of trace elements of interest. Sorption to foreign surfaces, complexation with agents present and aggregation of colloids (e.g., increasing ionic strength) result in a shift towards higher dimensions while desorption and dispersion processes mobilize the trace elements. Information on several components is therefore needed in speciation studies and a multielemental method of analysis having low determination limits must be applied. Instrumental neutron activation is appropriate to this kind of study because of its high sensitivity for simultaneous determination of a great-number of elements. Size fractionation techniques combined with INAA for the characterization of trace element species in natural waters will be discussed.  相似文献   

12.
The trace analysis of organic compounds presents a number of additional difficulties in comparison with the trace analysis of inorganic compounds. Thus special problems arise in sampling and in the storage of samples (e. g. because of the instability of many organic compounds). It is also difficult to choose suitable mild separation methods and to find highly sensitive, molecule-specific determination methods.  相似文献   

13.
论述了人体补充微量元素的几种主要方式,其中包括天然食物、无机化合物、有机化合物、复合微量元素药物和微量元素载体酵母等。  相似文献   

14.
National Bureau of Standards residual fuel oil Standard Reference Materials, SRM 1619, 1620a, 1634a, and former SRM 1634 were analyzed for 20 trace elements by instrumental neutron activation analysis to determine whether these materials are suitable trace element standards for elements other than the 6 elements certified in SRM 1634a. The SRM 1634a is a suitable standard for Ni, V, Se, Na, Zn, As, Cr, Fe, Ce, Sm and La but Co, Ba, Nd, Cs, Eu, Sc, and Sb appear to be heterogeneously distributed and are probably present in mineral particulates. The SRM 1619 is a convenient standard for V and for low Ni content oils, but SRM 1620a does not appear to be a suitable standard for any trace element investigated.To whom correspondence should be addressed.  相似文献   

15.
Debal E  Levy R 《Talanta》1978,25(3):183-184
Spectrophotometric techniques are useful for microdeterminations of many elements in organic compounds and some inorganic compounds. It is possible to determine most metals and some non-metals (Al, Co, F, Fe, Mo, P, Pd, Pt, Si, Sn, Ti...) by applying spectrophotometric techniques described in the literature (most often for trace analysis) and using commercial reagents.  相似文献   

16.
应用电离耦合等离子体原子反射光谱(ICP AES)和X射线荧光光谱(XRF),对新疆准噶尔六道湾侏罗纪低熟煤中36种微量元素的质量分数进行了测定,同时作岩石热解分析,有机碳测定,并对获取的各种数据进行回归分析,以考察它们之间的相关性。实验结果表明,除个别具有一定化学催化能力的元素外,多数常量元素及其所形成的矿物质,由于其对成煤有机物质的负增量作用,会明显降低煤的生烃潜力;微量元素对煤的生烃性能影响则较为复杂,既与其对煤的各种化学组成的有机亲和性之差异有关,亦与其在煤的大分子热裂解成烃中的某种化学催化作用有关。此外,由于某些微量元素所特有的古气候、古成煤沼泽类型的“指相”作用,亦能间接地指示煤的生烃潜力。其中Cu既是一个有着与煤的大分子物质较强亲和力的元素,又是一个可以显示古气候古成煤沼泽类型的“指相”元素,因而在指示煤的生烃潜力方面可能具有普适性。  相似文献   

17.
Speciation analysis of trace elements is the identification and/or measurement of the quantities of one or more individual chemical species in a sample. The general procedure starts with the separation of the species followed by the measurement of trace elements in the different fractions. The identification of the species may be done by UV-detection, mass spectrometry or other techniques. For the development of the methodology, and for in-vivo and in-vitro studies radiotracers are ideally suited. In speciation analysis of trace elements in biological fluids and tissues the search goes on for small inorganic and organometallic compounds, and for metal-protein complexes.  相似文献   

18.
For property-related characterization of inorganic materials, information is needed about bulk composition, distribution of elements, compounds, phases and structural features. Photons, electrons, charged ions or neutrons, often used as focused beams provide access to this information. The major trends in this field are the development or improvement of methods to obtain new information or to increase spatial resolution, detection power, precision and accuracy of analysis. The present state of the analysis of inorganic materials by using beam techniques is discussed in a selective manner. Emphasis is placed on the following problems, which are important for basic research and for development of high-technology materials: ultratrace bulk analysis in the pg g?1 to ng g?1 range; analysis for phases, trace elements and isotopes, including structural characterization; and surface analysis, with emphasis on the characterization of trace elements at surfaces, quantitative distribution of trace elements in heterogeneous structures, and surface structural analysis with atomic resolution.  相似文献   

19.
In most chemical analyses for inorganic determinations in environmental matrices the sample is physically destroyed by dissolution, calcination etc. These digestion procedures have to be validated in order to ensure that no contamination and/or losses have occurred which could affect the accuracy of the final results obtained; this validation can be made by using certified reference materials (CRMs).In the recent past, microwave digestion procedures have been developed and have been shown to offer the benefits of rapid sample preparation and reduced contamination risks; however, an incomplete dissolution was suspected in some cases, e.g. in interlaboratory exercises, for the analysis of organic matrices.The aim of this study was to test microwave digestion procedures for different environmental CRMs and to evaluate the suitability of these methods for the determination of some trace elements. The effects of chemical species (As, Hg and Se-species) on the total element recovery after digestion are discussed.  相似文献   

20.
用电感耦合等离子体原子发射光谱法选择测定了云南曲靖种植的人生果鲜果中十六种机元素含量,用热分析方法首次测定了人参果不同部位的无机元素氧化物总量,与同等条件下测定的甘肃产蕨麻干,云南文山产三七粉无机氧化物含量比较,对其中微量元素的7含量及价值做了分析比较,结果表明,无机元素含量以“人参果”籽中最高,也表明云南种植的人生果是一种富含各种生命微量元素的水果,具有极高的营养价值。  相似文献   

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