Determination of trace elements in porcine brain by inductively coupled plasma-mass spectrometry,electrothermal atomic absorption spectrometry,and instrumental neutron activation analysis

Methods have been developed for the analyses of trace metals in various areas of porcine brains, (temporal, parietal, frontal cortex, both right and left hemispheres). Determinations were carried out using inductively coupled plasma-mass spectrometry (ICP-MS) and electrothermal atomic absorption spectrometry (ETAAS). The elements investigated were Li, Mn, Cu, Zn, Cd, Hg, and Pb by ICP-MS and Cu, Cd, and Mn by ETAAS. For determination by ICP-MS, a method of standard additions calibration coupled with internal standards was used, and for ETAAS, standard additions calibrations were prepared. The accuracy of all methods was determined using NIST and IAEA certified reference material. A small number of pig brains were analyzed by instrumental neutron activation analysis for Cr, Co, Cs, Fe, Rb, Se, Sc, Sb, and Zn using the comparator method of analysis. Four separate NIST standard reference materials have been used to examine the validity of the comparator method.     

Trace elements in buried human bones and their value. A review

Since more than a decade, the trace element content of archaeological human bones is analyzed by physical anthropologists. Some of these elements give clues to the diets of ancient populations, others serve in estimating weaning age and the length of the active reproductive time span in human females. Therefore, trace element analysis becomes very important for palaeodemography and palaeoecology. On the other hand, a lot of basic research still has to be carried out, especially concerning the alteration of trace element concentrations in ancient bones either by soil processes or by microorganisms. The lack of reference series is obvious. Recommendations for the techniques to be applied are given, the parameters which may bias the interpretation of the data are discussed and the diagnostic potential of trace element analysis is demonstrated.     

Toxic heavy metals and other trace elements in foodstuffs from 12 different countries

A research program related to the assessment of toxic heavy metals and essential trace elements in foodstuffs has been carried out in 12 countries under the auspices of the IAEA. The main purpose of this program was to obtain data on the elemental concentrations of potentially toxic elements in foodstuffs in various countries, and to compare them with the maximum permissible levels specified in national legislation and international guidelines. High-priority elements for this study were As, Cd, Cr, Pb, Hg, and Se. Also of interest, but of lower priority, were Sb Cu, and Zn/ Emphasis was placed on the use of nuclear and nuclear-related analytical techniques, complemented by conventional methods, and on quality assurance.     

Intercomparison of techniques available at INETI in the analysis of two IAEA candidate research materials

Under contract with the IAEA, the epiphytic lichenEvernia prunastri was collected to prepare a multielement lichen reference material for quality assurance of environmental studies. An intercomparison run on trace and minor elements in this candidate research material (IAEA-336) was organized in which six analytical groups of the National Institute of Engineering and Industrial Technology (INETI) took part. INAA, PIXE, XRF, AAS, and ICP-ES were applied. The results obtained by different methods are compared, and their complementarity is discussed. As a quality control, the IAEA cabbage research material (IAEA-359) was analyzed. The results agree quite well with the estimated values given by the IAEA.     

Copper,selenium, and zinc concentrations in human milk during the first three weeks of lactation

Human milk samples were analyzed by neutron activation analysis (NAA) for three essential trace elements (Cu, Se, and Zn). Mothers' milk samples were collected from 25 lactating mothers from the Central Hospital, Tripoli, Libya. The average concentration level of Cu, Se, and Zn declined from 0.84 +/- 0.06 mg/L, 104 +/- 9.46 microg/L, and 16.1 +/- 2.67 mg/L at d 0 to 0.39 +/- 0.045 mg/L, 41.8 +/- 6.66 microg/L, and 4.95 +/- 1.3 mg/L, respectively, at d 20 of lactation. Copper and Zn levels in the Libyan mothers' milk were in agreement with reported levels from other countries, whereas Se was at a higher level. The Cu daily intake level is slightly higher than the RDA (Recommended Daily Allowance) value. Selenium and Zn have higher intake levels than the RDA values but within the tolerable upper intake levels.     

Experimental Study of Mobility and Kinetic Characterization of Trace Elements in Contaminated Sediments from a River Basin in Northern Peru

In the Jequetepeque basin (Peru), gold extraction activity has been performed in the last decades, leading to a release of metals and metalloids into the environment. Sediment samples were taken in the vicinity of two mines and analyzed. Extraction of metals and metalloids from sediments was carried out using single extraction procedures, acidic (HNO₃), and complexation (EDTA) leaching, in order to determine the mobility of trace elements. Results indicated that acidic extraction at low pH values increased the leachability of trace elements. EDTA showed a higher bioavailability of metals in sediments than acidic extraction under similar pH conditions because of its greater leaching capacity. This is an important issue in view of risk assessment analysis. The highest extractability was observed for Cd in all sediments with up to 90% of extraction after 1 h. The mobility index analysis indicated that faster kinetic leachability of some trace elements leads to a higher mobility in sediments, especially those near the active gold extraction mine. The ecological risk assessment suggested that the four river sediments were at high and very high risk levels, indicating that sediment contamination is an issue of environmental concern in the Jequetepeque basin of northern Peru.     

Leaching of Trace Elements from Biological Tissue by Formalin Fixation

In studies of trace elements in biological tissue, it is imperative that sample handling does not substantially change element concentrations. In many cases, fresh tissue is not available for study, but formalin-fixed tissue is. Formalin fixation has the potential to leach elements from the tissue, but few studies have been published in this area. The concentrations of 19 elements were determined by high-resolution inductively coupled plasma mass spectrometry in formalin in which human and rat brain samples had been stored for different time durations ranging from weeks up to several years. Additional analysis was carried out in fixed brain samples. There was substantial leaching of elements from the tissue into the formalin, and the leaching varied considerably between different elements. For example, formalin concentrations of As, Cd, Mg, Rb, and Sb increased more than 100-fold upon long-term (years) storage, while for Ni and Cr, the leaching was negligible. The degree of leaching was strongly time-dependent. In conclusion, formalin fixation and storage of biological tissue has the potential to leach substantial fractions of several trace elements from the tissue. The potential of leaching must be critically considered when using formalin-fixed biological tissue in trace metal analysis.     

The SET and ERITME indices: Integrative tools for the management of polluted sites

To address the lack of biological methods for assessing soil quality and its contaminant retention capacity and to provide a tool with which stakeholders can assess the risk of transfer of trace elements in the soil to the soil fauna, the Sum of the Excess of Transfers (SET) index from soil to the snail Cantareus aspersus has been broadened to include the internal concentrations of reference (CIRef) for 14 metals and metalloids (As, Cd, Co, Cu, Cr, Hg, Mo, Ni, Pb, Sb, Sn, Sr, Tl and Zn). Weighting the transfer of these elements by a risk coefficient (i.e., their toxicity point) provides a new assessment tool for stakeholders: the ERITME (Evaluation of the Risk of the Transferred Metal Elements) tool. This upgraded tool has been used to highlight unsuspected risks and revise management priorities at an industrial site. Moreover, using the tool to determine the risk from metal trace elements allows for improved environmental risk assessment, as ERITME is an integrative tool based on the real bioavailability of metals rather than chemical measures that often lead to unsatisfactory assessments of transfer. The SET and ERITME integrative tools, using snails as indicators of trace element zooavailability, can be used in environmental risk assessment.     

Trace elements in man.

It is likely that most, if not all, of the elements found to be essential in animals will be shown to be so for man, and the clinical picture produced by deficiency of the elements in the human patient will differ little from that seen in the animal, although this has been established for only five elements (I, Fe, Cu, Co and Zn). However, the link between lack of a given element in the soil and a human patient is far less direct and much more complex than that met with in the animal grazing on deficient pastures, except in isolated primitive communitis. Zn is the most protean of the trace elements and has been chosen to illustrate this in human practice. Excesses of essential elements (both trace and major) give rise to toxic effects and the importance of a proper balance especially of the transitional elements in the human diet is discussed with special reference to Cu, Zn and Fe. Certain non-essential trace elements are individual and community hazards: Cd, Pb and Hg are the principal offenders for humans. Mankind is now largely dependent on grassland products, cereals and livestock with increasing dominance of the former in human nutrition. This has reduced the bioavailability of trace elements so that study of trace metals, especially Zn and Cu, in skeletal and dental remains at human burial and occupation sites should prove useful in assessing the consequences of this striking change in dietary habits.     

不同利用强度下绿洲农田土壤微量元素有效含量特征

以地处极端干旱背景下的塔里木盆地南缘策勒绿洲为研究区,以绿洲化为视角,根据当地农民耕作习惯于2005年选择4块试验农田,分别代表当地典型的农田利用强度。基于单项指数(Ei)和综合指数(Ec)相结合的评价方法,分析了绿洲农田在不同利用强度下的土壤Fe、Cu、Mn、Zn等微量元素有效性,探讨了土壤微量元素与人为耕作管理措施之间的关系。结果表明:人为耕作管理强度会对土壤微量元素有效含量产生重要影响,绿洲不同位置农田因施肥强度和管理方式的差别,其土壤微量元素有效含量特征存在显著差异。绿洲内部农田土壤有效Fe、Cu、Mn、Zn含量显著高于绿洲边缘各样地,新垦农田土壤有效Fe、Cu、Zn含量均低于对照样地;绿洲内部农田土壤微量元素有效性最高,新垦农田最低;农田土壤微量元素有效性与土壤有机质存在显著的正相关关系。     

Morphological studies of the rat liver after experimental administration of carbon ashes and coal dust

The experiments were carried out in Wistar rats which were given intratracheally samples of carbon ashes or soil dust in the form of the respirable fraction. The morphologic changes and the glycogen content in the experimental animals' livers were evaluated. The content of the trace elements was determined in the applied carbon ashes and soil dust by means of the X-rays diffraction method. The results of the studies show that the morphologic changes in liver depend on the kind of dust and are related to the content of the trace elements and the free silicon dioxide in the carbon ashes and the soil dust.     

Methodological tests of the use of trace elements as tracers to assess root activity

Background and aims

There is increasing interest in how resource utilisation in grassland ecosystems is affected by changes in plant diversity and abiotic conditions. Research to date has mainly focussed on aboveground responses and there is limited insight into belowground processes. The aim of this study was to test a number of assumptions for the valid use of the trace elements caesium, lithium, rubidium and strontium as tracers to assess the root activity of several grassland species.

Methods

We carried out a series of experiments addressing the reliability of soil labelling, injection density, incubation time, application rate and the comparability of different tracers in a multiple tracer method.

Results

The results indicate that it is possible to achieve a reliable labelling of soil depths. Tracer injection density affected the variability but not the mean level of plant tracer concentrations. Tracer application rates should be based on pilot studies, because of site- and species-specific responses. The trace elements did not meet prerequisites to be used in a multiple tracer method.

Conclusions

The use of trace elements as tracers is potentially a very useful tool to give insight into plant root activity at different soil depths. This work highlights some of the main benefits and pitfalls of the method and provides specific recommendations to assist the design of tracer experiments and interpretation of the results.     

Trace elements in the atmosphere.

The distribution and behaviour of particulate trace elements in the atmosphere have been studied by continuous measurements for 5 years at seven non-urban sites in the United Kingdom. Samples have been taken regularly of airborne dust, rainwater and dry deposition: these have been analysed for up to 36 elements. Concentrations of trace elements vary considerably between sites but the relative concentrations are among uniform: this suggests similarity of origin or good atmospheric mixing. By comparing the relative concentrations with those in soil it is possible to differentiate between trace elements that are derived from soil and those that may be attributed to industrial activity. This classification is supported by estimates of the particle sizes in air. The deposition of trace elements can be related to the concentrations presnet in soil and to the annual removal by crops. Retrospective analyses of stored samples from one site describe the history of trace element concentrations in air since 1957. The sea surface is considered as a possible source of atmospheric trace elements.     

Concentration levels of major and trace elements in rice from sri lanka as determined by the k 0 standardization method

Instrumental neutron activation (INAA) with k ₀ standardization has been used to determine the concentration levels of a variety of major and trace elements (Al, As, Br, Cd, Cl, Co, Cr, Cs, Cu, Fe, Hg, K, La, Mg, Mn, Mo, Na, Rb, Sc, Se, and Zn) in rice grains (raw and parboiled) and in rice flour collected from local markets in Sri Lanka. In addition, the energy-dispersive X-ray fluorescence (EDXRF) analysis has been used to determine the three elements Ca, P, and S in powdered samples. To evaluate and assure the accuracy and precision of the k ₀ standardization method, the IAEA standard reference material V-8 rye flour was analyzed. The results obtained in the present investigation were compared with the results reported from other countries. All of the elements detected in the rice matrices from Sri Lanka were very low in concentration or within normal limits for food plants. Approximate daily dietary intakes of the individual elements supplied through rice were calculated and compared with the available literature values of daily allowances.     

Trace element content in breasts with fibrocystic disease

The trace elements antimony, bromine, cesium, cobalt, iron, rubidium, scandium, strontium and zinc were determined by instrumental neutron activation analysis in breast tissue samples with fibrocystic disease and in samples with fibroadenoma tumors. The histological lesions of each breast sample with fibrocystic disease were recorded, and a statistical analysis of the lesions in combination with the determined trace elements was carried out. The results showed that the element mean values in fibroadenoma tumors are higher than those of fibrocystic disease. Some other remarkable results of statistical examination are also presented.     

三峡库区两种特有植物天然生境与迁地生境土壤特征的比较

对库区特有的濒危植物荷叶铁线蕨、疏花水柏枝天然生境和迁地保护区生境及其土壤性质进行了调查分析和比较,结果表明：荷叶铁线蕨适宜于温暖湿润且排水良好的条件下发育的酸性淋溶土,养分含量高,多为粘土。疏花水柏枝适宜于亚热气候下弱碱性、养分含量低的冲积性砂砾质初育土、能耐一定程度的盐分。中国科学院武汉植物研究所内的迁地保护区土壤为湖滨沉积物上发育的中性粘土、主要养分和盐分含量介于两种天然生境土壤之间。微量元     

锡林河流域植物化学成分与植物类群及其生境关系的定量分析

植物化学成分与植物类群和所处生境关系密切。应用系统聚类分析、因子分析（采用主因子法和因子斜交旋转）等多元统计方法对锡林河流域１２２种植物的化学成分与植物类群和所处生境的关系进行了定量分析。分析结果说明上述方法可以较为准确地揭示数据中的如下规律：锡林河流域草原植物化学成分一方面与植物类群有关,受自身历史演化的决定,另一方面更受到所处生境条件的极大影响和制约。其中,禾本科、豆科植物分别具有其明显的化学成分特征;撂荒地群落与自然群落中植物、沙质与非沙质生境中植物化学成分差异较显著。因子分析中认为存在大量元素与微量元素两个公共因子,分别代表着植物中大量元素与微量元素的含量状况。豆科与禾本科相比,豆科植物因其具固氮能力,所含大量元素水平较高,而禾本科植物因细胞壁硅质化,含微量元素稍高;沙质生境因其养分贫瘠,植物的大量与微量元素均较非沙质生境中的低;特别是本区地带性土壤－栗钙土与特异性生境沙带中的疏林沙土相比,疏林沙土上植物大量与微量元素含量较栗钙土区植物明显偏低。     

Adaboost算法研究土壤微量元素含量与白血病的关系(英文)

目的:本文使用数据挖掘方法研究土壤中微量元素和白血病的相关性。方法:使用CFS-Adaboost算法研究我国29个省、市、自治区白血病死亡率的统计数据和土壤中微量元素含量的对应关系。结果:从29种微量元素中发现了13种微量元素与白血病相关,其中砷(As)的相关性较为明显。基于该13种微量元素,建立了土壤中微量元素和白血病致死率的数学模型,该模型的预报准确率可达到89.7%。结论:土壤中微量元素的含量与白血病有一定关系,其中砷(As)元素含量与白血病死亡率较为密切,这与近年文献报导的少量氧化砷治疗白血病效果显著相符合。以上研究发现,可以为研究土壤中微量元素和白血病的关系提供参考,对白血病的防治工作具有一定意义。     

Middle Jurassic tetrapod burrows preserved in association with the large sauropod Omeisaurus jiaoi from the Sichuan Basin,China

Here we report a Jurassic tetrapod burrow preserved in association with the partial skeleton of a large sauropod specimen of Omeisaurus jiaoi from Zigong, Sichuan Province, China. The ichnofossil can be divided into two parts, which may indicate two individual trace makers and some social behavior, although the possibility that they are two portions of one trace by a single trace maker cannot be ruled out. The burrow trace was examined via petrographic thin sections and carbonate analysis. Considering the spatial relationship of the burrows and the skeleton, it is likely that decomposition of the sauropod carcass preceded the formation of the burrows. It is possible that the process of decomposition improved the humus level of the soil, which would have attracted more soil-dwelling invertebrates and, by consequence, tetrapod predators thereof. The discovery of ZDM5051 has increased our understanding of global ichnofossil diversity.     

Effect of diabetes on trace-element concentration of blood

The effect of diabetes on trace elements concentration in blood of experimental animals has been studied by thin-target X-ray fluorescence analysis. Balb/C young adult mice, 6–8 wk old, were used in the study. About 100–200 μL venous blood was taken from each mouse for trace element analysis. The measurements were carried out on a commercial Wave-Length-Dispersive XRF System, with different X-ray tubes being used for maximizing the detection sensitivity of different groups of elements. Later on, the mice were made diabetic by an intravenous injection of Streptozotocin (250 mg/kg). Then, 2 and 3 wk after the injection, 100 μL of venous blood was drawn from each of the mice and analyzed for trace element concentration. In this way we were able to study the changes in blood trace elements caused by diabetes. The results and advantages of using experimental animals, under controlled conditions, to study trace element variations caused by different diseases, are discussed in the paper.