Investigation of the binding properties of heavy-metal-peptide complexes in plant cell cultures using HPLC-ICP-MS

Metal-induced, sulfhydryl-rich peptides (phytochelatins) found in plants, algae, yeasts and fungi have been described as sequesters and detoxifiers of heavy metal ions. High-performance liquid chromatography (HPLC) coupled on-line with inductively coupled plasma mass spectrometry (ICP-MS) has been used for the determination of heavy metal binding properties of phytochelatins in Silene vulgaris cell cultures. The induction of phytochelatins and the binding of heavy metals to these complexes were investigated by exposure of cell cultures with different concentrations of Cd, Cu, Pb and Zn. An in vitro heavy metal saturation assay and in vivo stress experiments with those elements able to bind to phytochelatins were carried out in order to characterize the binding affinity and binding stability of these compounds. It is shown that of the metals investigated, Cu binds most stably to phytochelatins under in vitro and in vivo conditions.     

Biomonitoring of metal contamination in a marine prosobranch snail (Nassarius reticulatus) by imaging laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS)

An imaging mass spectrometric method using laser ablation inductively coupled plasma spectrometry (LA-ICP-MS) was developed to determine Cu, Zn, Cd, Hg and Pb and metal distribution in longitudinal tissue sections of the marine snail Nassarius reticulatus (Gastropoda, Prosobranchia). Snails were sampled in northern Brittany (France) at three stations with different contamination levels.The quantification of metal distribution (imaging or mapping) in a thin slice of the snail tissue was carried out using different strategies: by one-point calibration and via matrix-matched laboratory standards using different biological materials (BCR 278, snail tissue, and rat brain). Together with the imaging of metals the distribution of two non-metals (carbon and sulfur) was analyzed. The imaging LA-ICP-MS analysis yielded an inhomogeneous distribution for all elements investigated. The detection limits for the distribution analysis of Cu, Zn, Cd, Hg and Pb measured by LA-ICP-MS were in the low μg g⁻¹ range.     

Heavy metal biosorption by bacterial cells

Microbial biomass provides available ligand groups on which metal ions bind by different mechanisms. Biosorption of these elements from aqueous solutions represents a remediation technology suitable for the treatment of metal-contaminated effluents. The purpose of the present investigation was the assessment of the capability of Brevibacterium sp. cells to remove bivalent ions, when present alone or in pairs, from aqueous solutions, using immobilized polyacrylamide cells of the microorganism in a flow-through system. The biosorption capacity of Brevibacterium cells was studied for lead, cadmium and copper. The metal cell binding capacity followed the order Cu > Pb > Cd, based on estimated q_max. These values, expressed as mmol metal/g dry weight cells, were 0.54 for Cu, 0.36 for Pb and 0.14 for Cd. Polyacrylamide-gel immobilized cells were effective in Pb, Cu and Cd removal. Lead removal was not affected by the presence of Cd and Cu; lead instead inhibited Cd and Cu removal. The desorption of the metal, by fluxing a chelating solution, restored the metal binding capacity of the cells, thus affording the multiple use of the same biomass in the remediation treatment. Received: 31 July 1997 / Revised: 22 December 1997 / Accepted: 30 December 1997     

Heavy metal biosorption by bacterial cells

Microbial biomass provides available ligand groups on which metal ions bind by different mechanisms. Biosorption of these elements from aqueous solutions represents a remediation technology suitable for the treatment of metal-contaminated effluents. The purpose of the present investigation was the assessment of the capability of Brevibacterium sp. cells to remove bivalent ions, when present alone or in pairs, from aqueous solutions, using immobilized polyacrylamide cells of the microorganism in a flow-through system. The biosorption capacity of Brevibacterium cells was studied for lead, cadmium and copper. The metal cell binding capacity followed the order Cu > Pb > Cd, based on estimated q_max. These values, expressed as mmol metal/g dry weight cells, were 0.54 for Cu, 0.36 for Pb and 0.14 for Cd. Polyacrylamide-gel immobilized cells were effective in Pb, Cu and Cd removal. Lead removal was not affected by the presence of Cd and Cu; lead instead inhibited Cd and Cu removal. The desorption of the metal, by fluxing a chelating solution, restored the metal binding capacity of the cells, thus affording the multiple use of the same biomass in the remediation treatment. Received: 31 July 1997 / Revised: 22 December 1997 / Accepted: 30 December 1997     

电感耦合等离子体质谱法测定地龙药材中铅、砷、汞、镉、铜元素的残留量

建立电感耦合等离子体质谱法(ICP-MS)测定不同产地和批次地龙药材中铅(Pb)、砷(As)、汞(Hg)、镉(Cd)、铜(Cu)5种重金属元素的含量.采用微波消解进行样品前处理,结果表明:5种重金属元素的线性关系良好(r≥0.999 6),平均回收率在92.8%~95.2%范围内,方法的检出限在0.001 0~0.092 mg/kg范围内.方法灵敏度高,重复性好,方法准确.不同产地和批次的样品中5种重金属元素均有检出.地龙药材中Pb、As、Hg、Cd、Cu这5种重金属元素需要重点监控.     

蒙药匝迪-5中有害金属元素的初级形态研究

采用ICP-ASE法对匝迪-5中的Cu,As,Cd,Hg和Pb元素进行了初级形态分析。结果显示Pb和Cu在头煎液和二煎液中的含量之和分别为0.25mg/kg和0.53mg/kg。As,Cd和Hg未检出;人工胃液中Pb的含量为0.02mg/kg,Cu的含量为0.37mg/kg。说明匝迪-5煎煮液和人工胃液中重金属均低于国家药典标准的要求。     

潮州市西湖沉积物中金属元素的污染特性研究

用原子吸收分光光度法研究了潮州市西湖沉积物中的铜、锌、铅、镉、锰、镍、镁、钙等金属元素的含量及分布规律。结果表明,铜、铅、锌、镉和镍是主要的重金属污染物,沉积物中5种重金属的平均含量为:铜584.7 mg/kg,铅149.1 mg/kg,锌360.9 mg/kg,镉1.2 mg/kg,镍76.7 mg/kg,均高于我国土壤背景值。     

Use of Particle-Induced X-Ray Emission for Evaluation of Competitive Metal Binding on Algae

Elemental concentrations of a unicellular alga,Chlorella vulgaris,were evaluated by particle-induced X-ray emission (PIXE). The probed algal cells generated a significant amount of phosphorus and sulfur X-ray emission. Phosphorus- and sulfur-containing compounds can provide potential binding sites for metal ions. Competitive binding of six metal ions, Ag, Ba, Cd, Cu, Hg, and Pb, to the algae was studied. It was found that Ag, Ba, Cd, Cu, and Pb are attached to a similar binding site with a binding efficiency varying in the sequence Pb > Cu > Ag > Cd > Ba. The binding of Hg to algae involves a different binding site. Silver was found to increase the binding of mercuric chloride to the algae.     

用植物叶片中重金属元素含量指示大气污染的研究

通过对潮州市区交通繁忙路段和对照区 (红山森林公园 )不同植物叶片重金属元素 (Pb、Cd、Cu、Zn)的含量研究 ,探讨了重金属含量与城市大气污染之间的关系。结果表明 ,植物叶片中的重金属元素富积量和大气中污染指数正相关。植物叶片的重金属元素富积量可较好和客观地指示市区大气的重金属污染状况。该研究为城市规划和环境保护提供了科学依据     

Monitoring of heavy metals in topsoils, atmospheric particles and plant leaves to identify possible contamination sources

The research reveals results of metal pollution on urban topsoil in relation to the metal content in leaves of two plant species and atmospheric particles. The content of pollutants (Ba, Cd, Cu, Fe, Mn, Ni, Pb, V and Ti) was determined by ICP-OES. Twenty-two samples of soil were collected over a six-month period from two different urban sites and one from a rural zone. Regarding the pollution level, the studied soils were found to be low. Results for enrichment (EF) and concentration (CF) factors showed that soils were enriched in Pb, Ba, Cu and Ni. However, both species of plants showed a common behavior for all elements acting as excluders. ANOVA and different multivariate statistical analyses confirmed that the main pollution source of soil was traffic and fertilizers. Cd, Fe, Mn, Ti and V elements were attributed to natural sources. Also, it was suggested that N. oleander leaf is useful as a bio-monitors of soil pollution by Cu. Similarly, a direct relationship was found between the content of Cu in soils with the Cu level in PM₁₀ atmospheric particles. The origin was attributed to dry and wet atmospheric deposition processes.     

六极杆碰撞反应池–ICP–MS法测定海水中痕量金属元素

建立了直接稀释法测定海水中痕量金属元素Cr,Cu,Zn,Cd,Pb的方法。样品经稀释10倍后,使用基体匹配及内标校正,采用六极杆碰撞反应池–电感耦合等离子体质谱仪直接测定稀释后海水样品中的5种元素Cr,Cu,Zn,Cd,Pb。各元素在0.0~100μg/L范围内均呈现良好的线性关系,线性相关系数(r~2)均大于0.999 0,方法检出限为0.004~0.209μg/L。测定结果的相对标准偏差为2.4%~4.4%(n=6),加标回收率为92%~113%。该方法简单快捷,适用于近岸海水中痕量元素Cr,Cu,Zn,Cd,Pb的分析。     

黔产市售绿茶重金属的含量特征及健康风险评估

为研究黔产市售绿茶中重金属的含量分布特征及健康风险,以五个生产加工地的黔产市售绿茶为研究对象,分析其9种重金属(Pb、Cr、Cd、Hg、Cu、Zn、Mn、Ni和As)含量,利用美国环境保护署(USEPA)推荐的健康风险评价模型进行人体重金属的健康风险评价。结果表明,五种茶叶中Cr、Cd、Pb、Hg、Cu和As含量均低于国家限量标准。黔产市售绿茶的重金属浸出率大小次序为Zn>Mn>Hg>As>Cd>Pb>Cr>Cu>Ni。健康风险评价结果表明,五个产地的绿茶中重金属通过饮茶途径所产生的健康危害个人年风险大小次序为Cd>As>Mn>Ni>Cr>Hg>Pb>Zn>Cu,茶叶中重金属通过饮茶途径所产生的个人健康危害年风险总和为4.33×10-6~5.73×10-6 a-1,均低于USEPA和ICRP推荐的最大可接受风险水平,表明重金属引起的健康危害极小,其对暴露人群造成的健康危害可忽略不计,绿茶中重金属均处于安全范围内。     

Effect of operating conditions on the removal of Pb2+ by microporous titanosilicate ETS-10 in a fixed-bed column

The breakthrough behavior of Pb2+ in an ETS-10 fixed bed was experimentally examined at various operating conditions. Results showed that the adsorption amount of Pb2+ ions per unit mass of ETS-10 particles in a column is about 1.68 mmol/g under the experimental conditions. This amount was not markedly affected by the operating conditions because of the rapid adsorption rate of Pb2+ ions on ETS-10. In the presence of competitive metal ions, the amount of Pb2+ adsorbed on ETS-10 was slightly reduced. An overshoot of the effluent concentrations of competitive metal ions Cu2+ and Cd2+ was observed in the adsorption systems of binary and ternary solutions. This is ascribed to the replacement of pre-adsorbed Cu2+ and Cd2+ ions by Pb2+ ions. The ETS-10 column broken up by Pb2+ ions can be regenerated by using an EDTA-Na2 solution and the regenerated column can be reused.     

Metal Ions Uptake by Chelating Resin Derived from o-Substituted Benzoic Acid and its Synthesis,Characterization and Properties

Summary: Chelating resin [AFM] was synthesized by condensation of Anthranilic acid, Formaldehyde with m-Cresol. The chelating resin was characterized by FTIR Spectra, Elemental Analysis and SEM Photographs. The thermal behavior of the resin was characterized by TGA. The thermodynamic parameters such as Activation Energy (E_a), Order of decomposition (n), Entropy of decomposition (S*), Enthalpy (H*) and Free energy (G*) were calculated by Coats and Redfern method using TGA graph. The chelating behaviour of the prepared resin was studied out with using some metal ions [Ni(II), Cu(II), Zn(II), Cd(II) and Pb(II)]. The sorption capacities of metal ions is found in the following order, Pb(II) < Zn(II) < Cd(II) < Cu(II) < Ni(II). The rate of half exchange was rapid t_1/2 < 20 min for lead ion. The separation of binary mixtures [Cu(II) and Zn(II) in brass and Pb(II) and Cd(II)] was successfully carried out using K_d value.     

Cadmium and Lead Content in Selected Fungi from Poland and Their Edible Safety Assessment

Mushrooms are able to accumulate toxic trace elements. This study investigates the content of cadmium (Cd) and lead (Pb) in selected species of fungi (Boletus badius, Boletus edulis, and Cantharellus cibarius) from the northeastern part of Poland and estimates their edible safety. The amount of Cd and Pb was determined by flameless atomic spectrometry using the iCE 3000 Series-Thermo. The mean content of Cd in analyzed mushrooms ranged from 0.370 to 2.151 mg/kg d.w., while Pb was found at the level of 0.243–0.424 mg/kg d.w. Boletus edulis was characterized by the highest content of Cd, whereas Cantharellus cibarius contained the biggest amount of Pb. Estimated exposure to the Cd intake expressed as percentage share in TWI (Tolerable Weekly Intake) was at the highest level in Boletus edulis (30.87%), which could be associated with the risk of excessive Cd accumulation in the body.     

Competitive adsorption behavior of heavy metals on kaolinite

Polluted and contaminated soils can often contain more than one heavy metal species. It is possible that the behavior of a particular metal species in a soil system will be affected by the presence of other metals. In this study we have investigated the adsorption of Cd(II), Cu(II), Pb(II), and Zn(II) onto kaolinite in single- and multi-element systems as a function of pH and concentration, in a background solution of 0.01 M NaNO3. In adsorption edge experiments, the pH was varied from 3.5 to 10.0 with total metal concentration 133.3 microM in the single-element system and 33.3 microM each of Cd(II), Cu(II), Pb(II), and Zn(II) in the multi-element system. The value of pH50 (the pH at which 50% adsorption occurs) was found to follow the sequence Cu相似文献   

土壤-温郁金体系中重金属的吸收富集研究

通过盆栽实验研究了铅（Pb）、镉（Cd）、铜（Cu）、汞（Hg）和砷（As）污染条件下,温郁金和种植土壤中重金属含量,分析了植物对重金属的吸收富集能力。结果表明,随着土壤中污染物的投加量增强,Cu、Pb、Cd、As元素主要集中在根部,而Hg元素由于其极易挥发的特性,其块根中含量反而随着Hg投加量的增加而减小。温郁金对不同元素的吸收富集能力不同,对Cd的富集能力最强,对Hg的富集能力最弱。     

Determination of trace elements in automotive fuels by filter furnace atomic absorption spectrometry

The determination of Cd, Cr, Cu, Pb and Ni was performed in gasoline and diesel fuel samples by electrothermal atomic absorption spectrometry using the Transverse Heated Filter Atomizer (THFA). Thermal conditions were experimentally defined for the investigated elements. The elements were analyzed without addition of chemical modifiers, using organometallic standards for the calibration. Forty-microliter samples were injected into the THFA. Gasoline samples were analyzed directly, while diesel fuel samples were diluted 1:4 with n-heptane. The following characteristic masses were obtained: 0.8 pg Cd, 6.4 pg Cr, 12 pg Cu, 17 pg Pb and 27 pg Ni. The limits of determination for gasoline samples were 0.13 μg/kg Cd, 0.4 μg/kg Cr, 0.9 μg/kg Cu, 1.5 μg/kg Pb and 2.5 μg/kg Ni. The corresponding limit of determination for diesel fuel samples was approximately four times higher for all elements. The element recovery was performed using the addition of organometallic compounds to gasoline and diesel fuel samples and was between 85 and 105% for all elements investigated.     

新型薄膜扩散梯度装置定量测量水环境中重金属形态

采用以纤维素透析膜为扩散相, 0.05 mol/L羧甲基纤维素钠(CMC)溶液为结合相的薄膜扩散梯度(DGT)装置(CMC-DGT)定量累积和测量水溶液中Cu²⁺, Cd²⁺和Pb²⁺的有效态; 考察了pH值和离子强度对CMC-DGT累积Cu²⁺, Cd²⁺和Pb²⁺的影响以及不同配体(乙二胺四乙酸二钠、 单宁酸和黄腐酸)对重金属有效态的影响; 测量了外加标的天然水和工业废水中重金属的有效态浓度; 并比较了不同结合相DGT装置对同一水体中重金属的有效态浓度. 实验结果表明, 0.05 mol/L CMC溶液对Cu²⁺, Cd²⁺和Pb²⁺累积容量分别为0.24, 0.11和0.45 mg/mL; 定量累积的最佳pH值范围分别为3.7～8.0, 4.7～9.0和4.7～8.0; 随着离子强度的增大, CMC-DGT对Cu²⁺, Cd²⁺和Pb²⁺的累积容量下降; CMC-DGT能够定量地累积配制水中的游离Cu²⁺, Cd²⁺和Pb²⁺, 回收率分别为92.1%, 100.6%和96.4%; 当有配体存在时, 随着配体浓度的增大, CMC-DGT测量的Cu²⁺, Cd²⁺和Pb²⁺有效态的浓度随之下降; 在过滤工业废水、 河水和湖水中, 不同结合相DGT装置对重金属有效态的测量值不同. 结果表明, CMC可作为DGT技术新的液态结合相.     

A new strategy for preparation of hair slurries using cryogenic grinding and water-soluble tertiary-amines medium

The investigation of trace metal contents in hair can be used as an index of exposure to potentially toxic elements. Direct determination of Cd, Cu and Pb in slurries of hair samples was investigated using an atomic absorption spectrometer with Zeeman-effect background correction. The samples were pulverized in a freezer/mill for 13 min, and hair slurries with 1.0 g l⁻¹ for the determination of Cu and Pb, and 5.0 g l⁻¹ for the determination of Cd, respectively, were prepared in three different media: 0.1% v/v Triton X-100, 0.14 mol l⁻¹ HNO₃, and 0.1% v/v of CFA-C, a mixture of tertiary amines. The easiest way to manipulate the hair samples was in CFA-C medium. The optimum pyrolysis and atomization temperatures were established with hair sample slurries spiked with 10 μg l⁻¹ Cd²⁺, 30 μg l⁻¹ Pb²⁺, and 10 μg l⁻¹ Cu²⁺. For Cd and Pb, Pd was used as a chemical modifier, and for Cu no modifier was needed. The analyte addition technique was used for quantification of Cd, Cu, and Pb in hair sample slurries. A reference material (GBW076901) was analyzed, and a paired t-test showed that the results for all elements obtained with the proposed slurry sampling procedure were in agreement at a 95% confidence level with the certified values. The cryogenic grinding was an effective strategy to efficiently pulverize hair samples.