Insight of EDX analysis and EFTEM: Are spherocrystals located in strombidae digestive gland implied in detoxification of trace metals?

Digestive tubules of Strombidae are composed by three cell types: digestive cells, vacuolated cells, and crypt cells. The last one is characterized by the presence of intracellular granules identified as spherocrystals. Such structures are known to occur in basophilic cells of gastropod digestive gland, where they are supposed to be involved in the regulation of some minerals and in detoxification. In this study, energy‐dispersive X‐ray analysis (EDX) and energy filtered transmission electron microscopy (EFTEM) were used to determine the elemental content of spherocrystals in two Strombidae, Strombus gigas and Strombus pugilis. In freshly collected individuals of both species, the following elements were detected: Ca, Fe, Mg, P, and Zn. Aluminum and Mn were also detected in S. gigas. Their presence in spherocrystals indicates that, in Strombidae, spherocrystals are involved in the regulation of minerals and essential trace metals. In order to answer the question “are spherocrystals involved in nonessential trace metals scavenging?,” artificial cadmium and lead exposure by both waterborne and dietary pathways was applied to S. pugilis. No evidence of cadmium (Cd(NO₃)₂) or lead (Pb(NO₃)₂) provided by food was found in spherocrystals. Cadmium provided in water (Cd(NO₃)₂ and CdCl₂) causes structural modifications of the digestive gland; however, this element was not trapped in spherocrystals. These results suggest that spherocrystals are not involved in detoxification of such nonessential trace metals. Microsc. Res. Tech., 2011. © 2011 Wiley‐Liss, Inc.     

Bioaccessibility of heavy metals in the seaweed Caulerpa racemosa var. corynephora: Human health risk from consumption

This study reports the total and bioaccessible concentrations of heavy metals (Mn, Fe, Cu, Zn, Cd and Pb) in the seaweed Caulerpa racemosa var. corynephora collected from local markets along the Andaman coast of Krabi Province, Thailand. Microwave-assisted acid digestion (EPA Method 3052) was used for sample preparation prior to total metal analysis. The in vitro Unified Bioaccessibility Method (UBM) was applied to assess the bioaccessibility of the metals in the seaweed samples. The total, gastric phase, and residual fraction concentration were determined by inductively coupled plasma-optical emission spectrometry (ICP-OES). The total amounts found in the seaweed samples, in ascending order were Cd?in vitro bioaccessibility method.     

Organometallic and organometalloid compounds as standards for microprobe analysis of epoxy resin embedded tissue

X-ray microanalysis of phosphorus, transition elements and heavy metals in biological tissue is frequently carried out on thin sections of specimens embedded in epoxy resin. A logical choice for the quantitive microprobe analysis of these specimens is a standard, consisting of a homogeneous solution of the elements of interest in the epoxy resin. Four kinds of compounds were found suitable for this purpose: (1) phenyl compounds containing group Vb elements, (2) cyclopentadienyl-derivatives, (3) a pentanedione derivative (acetylacetonate) and (4) complexes of metals with dialkyldithiocarbamates. In the latter case, the standard also contains sulphur. Standards for P, Sb (1) Mn, Fe (2) Ni (3) Cu, Zn, Cd, Hg, Pb, Bi (4) were prepared in Epon 812 or Spurr epoxy resin. The compounds were mixed with the resin (without accelerator) to which some propylene oxide may be added, and dissolved immediately or after short heating. The maximal concentration of metal was in the order of magnitude of several promilles to 1%. Solubility in the Spurr resin was better than in Epon 812. After addition of the accelerator, polymerization was carried out as usual. The compounds used are commercially available at low cost or can be easily prepared.     

植物性样品中重金属元素用火焰原子吸收法测定

本文采用扩大样品处理量,用稀硝酸润湿──炭化——高温灰化方法进行样品预处理,空氧一乙炔火焰直接测定溶液,氘灯扣除背景吸收原子吸收法,测定植物性食物中锌、铜、铁、锰、镉、铅元素的含量。平均回收率：锌 １０８％、铜 ９９％、铁 １１８％、锰９８％、镉９７％、铅 ９８％相对标准偏差：锌２．０２％、铜１１．２４％、铁１２．４１％、锰１．２７％、镉６．９０％、铅７．０３％     

Multivariate Statistical Techniques to Determine Essential and Toxic Elements in Biological Samples by X-Ray Fluorescence

X-ray fluorescence spectrometry was used to determine essential and toxic elements in tea leaves. Quantitative measurements were obtained for K, Mg, Cu, Zn, As, Sr, Fe, Co, Ca, P, S, Pb, Rb, and Mn. Pearson's product moment correlation coefficient with principal component analysis and hierarchical clustering analysis were performed to investigating the relationships between essential and nonessential elements in the dry herbal mass. From multivariate statistical analysis, Ca, Fe, P, Zn, and Mn were found to have strong positive correlations. While principal component analysis demonstrates that tea leaves were dominated by Fe and Cl in the first principal component, Pb and As were in the second principal component with cumulative variability of 84.4%. However, hierarchical clustering analysis indicated the presence of a cluster of four essential elements, one cluster containing toxic and essential elements, and one cluster composed of toxic elements. The results of this study improve understanding of the correlation between essential and toxic elements in biological samples such as tea leaves.     

Preserving elemental content in adherent mammalian cells for analysis by synchrotron‐based x‐ray fluorescence microscopy

Trace metals play important roles in biological function, and x‐ray fluorescence microscopy (XFM) provides a way to quantitatively image their distribution within cells. The faithfulness of these measurements is dependent on proper sample preparation. Using mouse embryonic fibroblast NIH/3T3 cells as an example, we compare various approaches to the preparation of adherent mammalian cells for XFM imaging under ambient temperature. Direct side‐by‐side comparison shows that plunge‐freezing‐based cryoimmobilization provides more faithful preservation than conventional chemical fixation for most biologically important elements including P, S, Cl, K, Fe, Cu, Zn and possibly Ca in adherent mammalian cells. Although cells rinsed with fresh media had a great deal of extracellular background signal for Cl and Ca, this approach maintained cells at the best possible physiological status before rapid freezing and it does not interfere with XFM analysis of other elements. If chemical fixation has to be chosen, the combination of 3% paraformaldehyde and 1.5 % glutaraldehyde preserves S, Fe, Cu and Zn better than either fixative alone. When chemically fixed cells were subjected to a variety of dehydration processes, air drying was proved to be more suitable than other drying methods such as graded ethanol dehydration and freeze drying. This first detailed comparison for x‐ray fluorescence microscopy shows how detailed quantitative conclusions can be affected by the choice of cell preparation method.     

Spectroscopic and microscopic characterization of atmospheric particulate matter

The aim of this study was to investigate the chemical properties of atmospheric particulate matter collected during post biomass burning events from November to December 2015. The types of particulate samples collected from the study area were total suspended particulates (TSP) and particulates less than 2.5?µm (PM_2.5). Multiple methods were used for the qualitative and quantitative characterization. Fifteen major and minor trace metal analyses were performed using acid digestion followed by inductively coupled plasma mass spectrometry analysis. Infrared spectroscopy was used for the identification of functional groups of organic compounds present in the samples. In addition, field emission scanning electron microscopy–energy dispersive X-ray spectroscopy was used for morphological characterization and microanalysis of individual particles. The average measured concentration of trace metals in TSP and PM_2.5 follows the order of Zn?>?Fe?>?Al?>?Cu?>?Pb?>?Mn?>?V?>?Cr?>?Ni?>?Sn?>?As?>?Hg?>?Cd?>?Ag?>?Co. Enrichment factor analysis showed strong anthropogenic contributions of Hg, Ag, Zn, Cd, Pb, As, Cu, and Sn in the samples. Field emission scanning electron microscopy–energy dispersive X-ray spectroscopy shows that three types of particles were present that originated from crustal and anthropogenic sources. Furthermore, the infrared measurements indicate that most compounds were organic acids and aromatic hydrocarbons.     

ICP-MS测定硼矿区饮用水和尿样中的硼及多种元素

The application of inductively coupled plasma mass spectrometry (ICP-MS) for determination of boron in water and urine samples was described. The detect limit (3σ) was 0.057 μg/L. The precision of the method was less than 2%. Multi-elements including Cr, Cu, Cd, Ba, Sr, Mn, Co, Tl, Li, Pb, Ca, Fe, K, Na, Mg, P, Si and Zn could be measured simultaneously. The method was successfully used in practice.     

南宁市售茶叶重金属含量及健康风险评价

采用电感耦合等离子体质谱(ICP–MS)法测定了南宁市售茶叶中Cu、Zn、Pb、Cd、As、Cr和Ni七种重金属的含量,运用内梅罗综合污染指数对重金属污染水平进行评价,运用靶标危害系数法对重金属人体健康风险进行评估.结果表明:试验方法精密度和准确度都较高,市售茶叶中重金属Cu、Zn、Pb、Cd、As、Cr和Ni的含量差...     

微波消解-电感耦合等离子体质谱法测定食品中18种元素

建立了食品中钠、镁、铝、钾、钙、钒、铬、锰、铁、镍、铜、锌、砷、硒、镉、锡、汞、铅的电感耦合等离子体质谱（ICP–MS）测定方法。样品经过微波消解,在线加入内标校正基体效应,通过修正方程校正质量数干扰,各元素校正曲线的相关系数均大于0.9995。对多种国家生物标准物质进行验证,测定值与标准值相符,相对标准偏差RSD（n=6）小于8.71%,加标回收率为71.8%～109.5%。     

Elemental changes in the brain, muscle, and gut cells of the housefly, Musca domestica, exposed to heavy metals

The toxic effects of heavy metals on organisms are well established. However, their specific action at the cellular level in different tissues is mostly unknown. We have used the housefly, Musca domestica, as a model organism to study the toxicity of four heavy metals: copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb). These have been fed to larvae at low and high, semi-lethal concentrations, and their accumulation in the head, thorax, and abdomen was subsequently measured in adult flies. In addition, their impact on the cellular concentration of several elements important for cell metabolism-sodium (Na+), magnesium (Mg++), phosphorous (P), sulphur (S), chloride (Cl-) and potassium (K+)-were measured in neural cells, muscle fibers, and midgut epithelial cells. Our study showed that the heavy metals accumulate mainly in the abdomen, in which the concentrations of two of the xenobiotic metals, Cd and Pb, were 213 and 23 times more concentrated, respectively, than in controls. All the heavy metals affected the cellular concentration of light elements in all cell types, but the changes observed were dependent on tissue type and were specific for each heavy metal, and its concentration.     

Effects of trace metal elements on ultrastructural features of hepatopancreas of Armadillidium granulatum Brandt, 1833 (Crustacea,Isopoda)

This study was conducted to compare metals bioaccumulation in the terrestrial isopod Armadillidium granulatum collected from Ghar El Melh lagoon. We focused on recognizing the effects of trace elements on hepatopancreas functional role. To this end, isopod specimens were exposed for 3 weeks to sediments contaminated with cadmium, copper, zinc, mercury, and nickel. Three concentrations were used in duplicate for each experimental condition. At the end of the experiment, metal body burdens were determined using flame atomic absorption spectrometry. Results of the bioaccumulation factor (BAF) showed that the species A. granulatum was classified as a Cu macroconcentrator (BAF > 2) and a Zn deconcentrator (BAF < 2). Dose dependent morphological and histological changes were observed in the hepatopancreas cells using transmission electron microscopy. The predominant features were: microvillus border disruption, condensation of the cytoplasm with increasing endoplasmic reticulum, mitochondria, lysosomes and granules that accumulated metals in B and S cells. The number of lipid droplets decreased especially after Cd, Zn, Hg, and Ni treatments. This study demonstrated that the terrestrial isopod A. gramulatum could be a good indicator of soil metal contamination.     

Histochemical and ultrahistochemical localization of heavy metals in calf organs

Cadmium, zinc, selenium, and copper were administered, singly or in combination, orally or subcutaneously. Experiment I included 32 calves of both sexes; six received Cd (two groups), Zn, Cd, and Zn, and Cd and Se (two groups) and one group was a control. In Experiment II (21 bulls), three were given Cd, Cd, and Cu, and Cd and Zn, respectively, and one group was a control. For light microscopy, in Experiment I the highest amounts of silver granules were present in the samples of liver, small intestine, and vesicular gland of all the exposed groups; in Experiment II the most affected organs were liver, kidney, and small intestine. For electron microscopy, in Experiment I, after administration of Cd and Zn, the highest amounts of granules were seen in the cytoplasm of hepatocytes and cells of the proximal and distal renal tubules and the lowest amounts were found in glandular cells of the pancreas. Administration of Cd and Se resulted in the presence of large numbers of granules in the nuclei and nucleoli of spermatogonies. In Experiment II, ingestion of Cd and Zn in feed led to the appearance of highest amounts of granules in the nucleoli, nuclei, and cytoplasm of cells in testes, kidneys, and pancreas. Following Cd intake, the highest accumulation of granules was observed in the nucleoli of hepatocytes and cells of the proximal and distal renal tubules. Combined Cd and Cu produced the highest number of granules in cells of the proximal and distal renal tubules and in the nucleoli and nuclei of germinal epithelium.     

利用主成分分析法选择止血类中药中特征金属元素

采用火焰原子吸收分光光度法测定了七种止血类中药中Fe、Mn、Cu、Zn、Mg和Ca金属元素含量。根据测定数据,利用主成分分析法进行特征元素的选取,选择Fe、Mn、Zn、Ca四种元素为特征金属元素,并利用主成分得分值作聚类分析,结果表明主成分分析用于中药中特征元素的提取是一种具有优势的分析方法。     

黄河水中固体粒子与Cu、Pb、Zn、Cd相互作用的离子交换率E(%)-pH曲线的研究

采用离子交换法和原子吸收分光光度法研究了黄河游水体中固体粒子(表层沉积物〕与铅、铜、锌、镉液-固界面的相互作用,及各种环境因素对颗粒表面吸附作用的影响,绘制了离子交换率E(％)-pH曲线。实验结果为:1)铜、铅、锌、镉均以一价络离子形式在固体粒子表面进行阳离子交换反应;2)pH值是控制金属离子向固相迁移的主要因素,且E(％)随pH升高而增大。在天然黄河水pH范围(8.0-8.5)内,四种金属离子的E(％)可达80-100％;3)E(％)-pH曲线会随金属离子浓度的增高而向高pH方向移动,表明E(％)下降;4)随固体粒子浓度增大,E(％)就会增高,使E(％)-pH曲线向小pN方向移动;5)固体粒子的粒度增大也会使离子交换率下降;6)加入一定浓度的甘氨酸会使镉离子交换率E(％〕增大。     

FASS法测定高良姜中八种金属元素含量

采用广西产高良姜为原料,以硝酸-高氯酸法（V：V=3：1）常压微沸条件下消解样品,应用火焰原子吸收法测定其中的Ca、Mg、Fe、Co、Ni、Cu、Zn、Mn等8种金属元素的含量,并研究了测定不同元素的仪器最佳工作条件。结果表明：在高良姜中含有丰富的Mg、Ca、Mn、Fe、Zn,在测定的8种元素中,Ca、Mg含量最高达2000μg.g-1;最低为Co,仅1μg.g-1。     

ICP—AES法测定盒果藤中的微量元素

目的：建立盒果藤中微量元素的测定方法。方法：采用HN03-H2O2高压消解罐法消化处理样品,用电感耦合等离子体发射光谱法（ICP—AES）同时测定盒果藤中Cu、Zn、Fe、Ca、Mg、Mn、Sr等7种微量元素。结果：该方法的RSD（n=9）在0．6～3．3％内,元素回收率在86．9—104．8％之间,测定结果较理想。结论：该方法简便,快速准确,适于分析测定盒果藤中的微量元素,测定结果发现盒果藤中合有丰富的Cu、Zn、Fe、Ca、Mg、Mn、Sr元素,对今后研究其药理作用有重要的意义。     

ICP-AES法测定花叶中钾、钙、镁、锌、铜、铁、硼、硫、磷含量

用电感耦合等离子原子发射光谱法测定花卉叶片的九种元素含量,是一种快速、方便、实用的定量分析方法。     

Chemical Assessment of Bottled Drinking Waters by IC,GC, and ICP‐MS

Abstract

Bottled water brands, consisting of both local and imported types, collected from Doha city, Qatar, were evaluated for their suitability for human consumption. Water quality constituents that were analyzed include trihalomethanes (THM) by GC‐ECD, turbidity, TDS, total hardness, total alkalinity, pH, EC, major anions by IC, and major cations and trace metals by ICP‐MS. The data obtained were compared with the WHO and the USEPA drinking water standards. As, Se, Ba, and Cu were undetected in all water samples. The levels of potential toxic metals in the studied brands were generally low, except for three brands that had Cd and Pb which exceeded the WHO limits. Fluoride was generally present in all bottled water brands at levels less than the lower optimum level. The reported data for pH, turbidity, TDS, EC, alkalinity, hardness, major anions, and major cations were generally in compliance with the WHO and the USEPA standards, with exception of five brands, where the levels of TDS, EC, F, and NO₃ exceeded the WHO recommended limits. Also, it was found that the concentrations of NO₃ F, Fe, Cr, Zn, and Pb were higher in the local brands. The levels of Cd, Mn, Ca, Mg, EC, alkalinity, SO₄, TDS, THM, and hardness were higher in the domestic brands, when compared to the imported ones. The levels of Cl, pH, turbidity, and Na in the domestic brands were comparable to imported ones. Three THM were found in 29% of water samples with three brands having CHCl₂Br and CHCl₃ levels exceeding the WHO standards.

Comparison of the results of this study with the reported label values of both domestic and imported bottled water showed good agreement with pH and K values, but significant variation for Ca, Mg, F, NO₃, and SO₄ in the imported brands and relatively low variation in the domestic brands. The results of chemical analysis of SRM 1460, trace elements in water, were generally in good agreement with NIST certified values.     

石墨消解连续光源原子吸收法测定废气中重金属

采用DEENA石墨消解仪对采集的废气样品进行前处理,利用contrAA700连续光源原子吸收光谱仪测定样品中重金属铜、锌、镍、铅、镉、锰。本试验优化了消解液的组合,使样品消解更完全,且克服了传统火焰原子吸收法需要更换空心阴极灯的缺陷,提高了分析速度。各元素的检出限分别为铜0.0025mg/m~3,锌0.0012mg/m~3,镍0.0038mg/m~3,锰0.0025mg/m~3,铅0.0075mg/m~3,镉0.0025mg/m~3。各元素的回收率分别为铜94.2%,锌102.5%,镍95.6%,锰104.1%,铅97.3%,镉95.3%。本方法具有较高的准确度,相比传统的火焰原子吸收法有更高的工作效率,适用于废气中多种重金属的同时测定。