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实验测定了海水中氨基酸存在下Ｃｕ（Ⅱ）在ｒ－ＭｎＯＯＨ上吸附的等温线、Ｃｕ（Ⅱ）％－－ｐＨ曲线和Ｃｕ（Ⅱ）％－氨基酸深度曲线。结果表明，较低浓度氨基酸对Ｃｕ（Ⅱ）在ｒ－ＭｎＯＯＨ上吸附没有影响，而较高浓度氨基酸却起抑制作用，这主要是由于海水中Ｃｕ（Ⅱ）－氨基酸络合反应与ｒ－ＭｎＯＯＨ竞争Ｃｕ（Ⅱ）所致。此外，海水中较高浓度氨基酸只使Ｃｕ（Ⅱ）在ｒ－ＭｎＯＯＨ上吸附的表面分级离子交换稳定常数Ｋｉ（ｉ 相似文献
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《Marine Chemistry》1991,32(2-4)
The adsorption of trace metals (Pb, Zn, Cu, Cd and Hg) on calcite, kaolinite and bentonite has been studied in Krka river water of various salinities (S = 3, 20 and 38‰).Model experiments were performed at pH 8 in natural water and in UV-irradiated water samples to determine the importance of natural soluble organic matter. Cold vapour atomic absorption spectrometry was used for the Hg determination, and a differential pulse anodic stripping voltammetry (DPASV) method for determination of other trace metals, using either a hanging mercury drop electrode or a mercury-coated glassy carbon working electrode. The following results have been obtained on calcite:
- 1. (1) a powerful absorption of Pb and Zn was observed for both natural and UV-irradiated waters at S=20‰;
- 2. (2) a strong adsorption of Hg was observed in natural water, and significantly lower adsorption in UV-irradiated water at all three salinities, particularly at low salinity;
- 3. (3) Cd adsorption was of medium intensity in both waters at S=20‰;
- 4. (4) Cu was practically not adsorbable in both waters at S=20‰ if the total Cu ion concentration was lower than the copper complexing capacity value;
- 5. (5) Cu adsorption was of a medium intensity at S=38‰. It has not influenced by the EDTA model ligand.
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本文利用Cu2+处理泥蚶血红蛋白（Tg-HbⅡ），分别检测Cu2+对Tg-HbⅡ的过氧化物酶活性及其结构的影响，同时检测Pro对Cu2+作用下Tg-HbⅡ的保护作用。结果表明:随着Cu2+浓度的增加，Tg-HbⅡ的过氧化物酶活性逐渐丧失，Cu2+抑制Tg-HbⅡ的过氧化物酶活性类型属于非竞争-竞争混合型抑制，其失活速率具有浓度依赖性，失活过程呈单相变化，表现为一级反应动力学，并且不同浓度Cu2+能影响Tg-HbⅡ的三级结构变化；另外，Pro对Tg-HbⅡ的空间结构及其过氧化物酶活性具有保护作用，能阻止Tg-HbⅡ的聚沉、恢复Tg-HbⅡ的结构与过氧化物酶活性。 相似文献
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Constant M.G. Van Den Berg 《Marine Chemistry》1984,14(3):201-212
The metal complexing ability of surface water of the Irish Sea has been measured by the MnO2 adsorption method. In all samples strong copper-chelating compounds are present at concentrations of 60–150 nM, with conditional stability constants (log values) of 10.0–10.4. The concentrations of Cu, Pb and Cd in the samples are 16–39 nM, 1–7 nM and 0.1–2 nM, respectively; much less than the ligand concentrations. The organic compounds form complexes with 94–98% of dissolved copper, and therefore constitute the major form of copper in surface water of the Irish Sea. Recalculation of speciation of the inorganic fraction of copper in seawater reveals that the major complex ion is that of CuCO30 (60%), followed by CuOH+ (16%) and Cu(OH)20 (16%). Complexes with borate ions form a small and rather insignificant fraction of 1%. 相似文献
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采用生物化学方法测定和分析了野生黄唇鱼(Bahaba flavolabiata)肌肉和鳔的营养成分。黄唇鱼肌肉和鳔的营养成分都属于高蛋白、低脂肪类型。肌肉的必需氨基酸模式优于FAO/WHO的理想模式,氨基酸含量、必需氨基酸含量和鲜味氨基酸含量均较高,种类齐全。鳔的氨基酸组成较FAO/WHO的理想模式低,但其蛋白质含量高达35.90%,高于其他已报道的水产品,粗脂肪和粗灰分含量较低;氨基酸种类齐全且含量丰富,富含鲜味氨基酸;在氨基酸测定中发现了牛磺酸、γ-氨基丁酸、鸟氨酸和羟脯氨酸等4种具有重要生理功能的衍生氨基酸。肌肉和鳔的支/芳值均接近正常人的水平,不饱和脂肪酸含量较丰富,与饱和脂肪酸含量的比值分别为1.45和1.51,含有人体所必需的钙、钠、钾、镁、铁、铜、锌等元素。结果表明,黄唇鱼肌肉具有较高的营养价值,肌肉和鳔均属于优质的海产蛋白源。 相似文献
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A conventional amino acid analyzer was modified to allow detection of dissolved free amino acids in a direct injection of 0.5 to 2.0 ml of seawater. The amino acids were monitored fluorimetrically by reaction with o-phthaldialdehyde after column chromatography. The accuracies of two commonly employed desalting methods, cation exchange resin and copper Chelex, were determined by comparison with the direct injection method. After correcting the results of the desalting methods for the procedural blank and recovery rate for each individual amino acid, the amino acid compositions on a mole percent basis as determined by these methods resembled approximately the true composition determined by direct injection. However, on an absolute basis the cation resin method overestimates and the copper Chelex method underestimates the total amount of dissolved free amino acids. The reasons for these discrepancies are discussed. Using the direct injection method, the spectra of dissolved free amino acids in surface seawater samples from different locations were determined. As opposed to the relatively uniform patterns reported in most past investigations, the amino acid spectra found were highly variable. In a number of samples, the acidic amino acids dominated the spectra. Valine was also high in many samples. In a depth profile the deep samples were dominated by arginine. Application of the method to real-time shipboard analyses of dissolved free amino acids is discussed. 相似文献
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Total copper (Cu(T)), copper ion activity (pCu) and the copper complexation capacity (CuCC) were determined in samples of seawater collected in July 2003 from the Venice Lagoon. Cu(T) and CuCC showed considerable spatial variability: Cu(T) ranged from 1.8 to 70.0nM, whereas the CuCC varied from 195 to 573nM. pCu values varied from 11.6 to 12.6 and are consistent with those previously reported in estuarine and coastal areas (10.9-14.1). The range of Cu(T) values compares well with those reported in the past in the lagoon and in the adjacent Adriatic Sea. The highest concentrations of Cu(T) were found in samples collected near the industrial area of Porto Marghera, whereas the lowest were measured near the Chioggia and Malamocco inlets, where an intense tidally-driven renewal of seawater takes place. Although CuCC showed a high degree of spatial variability, the values recorded in the Venice Lagoon are comparable to those reported in other estuarine systems. In addition, CuCC was positively correlated with dissolved organic carbon (DOC), suggesting that organic ligands responsible for Cu complexation are part of the bulk organic matter pool in the lagoon. The CuCC:Cu(T) molar ratio was, on average 55:1, indicating that a large excess of complexation capacity exists in the Venice Lagoon. The high levels of CuCC and the narrow range of pCu indicates the importance of the role played by organic ligands in controlling the free ion Cu concentrations in the lagoon, and as a consequence, regulating its availability and/or toxicity. 相似文献
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重金属、螯合剂以及铁、锰离子对叉边金藻生长的影响及其混合效应 总被引：2，自引：0，他引：2
采用微藻一次培养实验,研究了铜、锌、镉离子,微藻渗出物,螯合剂EDTA对叉边金藻生长的影响。铜、镉,对叉边金藻的毒性较强,锌较弱。螯合剂EDTA对叉边金藻的生长有促进作用。混合实验表明,铁、锰离子,EDTA都能有效地降低铜的毒性;藻渗出物也能在一定程度上缓解铜的毒性;镉、锌对铜的毒性有拮抗效应。此外,通过测定介质和细胞铜的含量,研究了铜在细胞表面的吸附行为,并在铜致毒机理以及其他化学因子的去毒机理方面作了探讨。 相似文献
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Stephen R. Piotrowicz George R. Harvey Deborah A. Boran Clifford P. Weisel M. Springer-Young 《Marine Chemistry》1984,14(4):333-346
The interactions in seawater of cadmium, copper, and zinc with natural levels of marine humus (fulvic and humic acids) were studied using differential pulse anodic stripping voltammetry (DPASV). Interactions with Cu were also examined by ultraviolet spectrophotometry. The degree of interaction relates to the structure of the particular fulvic or humic acid tested. Marine fulvic and humic acids with different equivalent weights and varying degrees of aromaticity and heteroatom substitution were tested to assess the relative importance of these fundamental structural features in determining the degree of interaction. An index of heteroatom substitution, derived from proton magnetic resonance spectra of these materials, when combined with equivalent weights correlated with the nature and degree of metal interaction. Both marine fulvic and humic acids appreciably interacted with Zn. In contrast, the extent of interaction of fulvic acids with Cu appears to be related to their structure while humic acids appear to interact with Cu regardless of structure. Cadmium interacts only with mature, highly crosslinked humic acids. 相似文献
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ＳｅａｗａｔｅｒｅｎｖｉｒｏｎｍｅｎｔｃｏｐｐｅｒｒｅｑｕｉｒｅｍｅｎｔｏｆｅｇｇｈａｔｃｈｉｎｇａｎｄｎａｕｐｌｉａｒｍｅｔａｍｏｒｐｈｏｓｉｓｏｆＰｅａｎｅｕｓｃｈｉｎｅｎｓｉｓ￥ＹｕａｎＹｏｕｘｉａｎ；ＱｕＫｅｍｉｎｇ；ＬｉｕＬｉｂｏ；ＧａｏＣ... 相似文献
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青鳞鱼下脚料水解蛋白的制取及其营养评价 总被引：11，自引：0，他引：11
以青鳞鱼（Harengula zunast)下脚料为原料，采用碱萃取，蛋白酶水解，浓缩，喷雾干燥等手段，制得水解鱼蛋白。研究了碱萃取，蛋白酶水解条件及不同沉淀方法对水解鱼蛋白沉淀效果的影响，并对水解鱼蛋白制品营养价值进行了评价，结果表明，下脚料水解鱼蛋白制品含粗蛋白72．9％，氨基酸总量67．6％，其中必需氨基酸占44．6％，氨基酸分为96，苏氨酸为其限制性氨基酸（1973年FAO／WHO标准），无机盐钙，镁，铁，锌，铜，磷含量丰富，以有机溶剂（异丙醇，乙醇)为沉淀剂沉淀水解蛋白时，粗蛋白损失率约为30％（干基计）。 相似文献
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Zhang L Liu X You L Zhou D Wu H Li L Zhao J Feng J Yu J 《Marine environmental research》2011,72(1-2):33-39
Copper is an important heavy metal contaminant with high ecological risk in the Bohai Sea. In this study, the metabolic responses in the bioindicator, Manila clam (Ruditapes philippinarum), to the environmentally relevant copper exposures were characterized using NMR-based metabolomics. The significant metabolic changes corresponding to copper exposures were related to osmolytes, intermediates of the Krebs cycle and amino acids, such as the increase in homarine, branched chain amino acids and decrease in succinate, alanine and dimethylamine in the copper-exposed clam gills during 96 h exposure period. Overall, Cu may lead to the disturbances in osmotic regulation and energy metabolism in clams during 96 h experimental period. These results demonstrate that NMR-based metabolomics is applicable for the discovery of metabolic biomarkers which could be used to elucidate the toxicological mechanisms of marine heavy metal contaminants. 相似文献
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Nineteen amino acids in sediments from the Ebro Delta (Spain) have been determined by HPLC. According to quantitative and qualitative data it is suggested that the distributions reflect organic autochthonous contributions and are constrained by environmental conditions of deposition.In the more reducing areas (8.7–11.6 mg total amino acids/g of dry sediment) hydroxyproline, threonine, glycine and glutamic acid are the major amino acids, while in the off-shore stations (1.0–2.7 mg total amino acids/g of dry sediment) ornithine, lysine, phenylalanine, serine and valine are dominant. In these samples absolute concentrations decrease with water depth.The analysis of two cores has shown that sulfur-containing and neutral branched-chain amino acids are the least resistant to geochemical degradation. Within the basic fraction, which appeared to be the most stable, ornithine is produced geochemically and preferentially in the more oxic sediments. 相似文献
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The natural “complexing capacity” of aquatic systems was determined using titration with cupric ions. It was compared with “complexing capacity” determined in the presence of both EDTA, used as a model for organic substances, and of EDTA and γ-Al2O3. The γ-Al2O3 was used as a model for solid particles of hydrous oxide in natural waters. The adsorption isotherm of copper in seawater on γ-Al2O3 particles was determined with and without EDTA.For EDTA alone and for the Cu—EDTA complex, it was found that they are not adsorbed on γ-Al2O3 in the natural seawater. However, by adsorption on solid particles, the labile ionic Cu-complex can be removed from the seawater. 相似文献
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Geret F Manduzio H Company R Leboulenger F Bebianno MJ Danger JM 《Marine environmental research》2004,58(2-5):619-623
The potential of the first line of the active oxygen-scavenging system, partial cDNA encoding Cu/Zn superoxide dismutase (SOD) was isolated in three aquatic mollusc species: Ruditapes decussatus (marine clam), Dreissena polymorpha (continental water mussel) and Bathymodiolus azoricus (hydrothermal vent mussel). These SOD cDNA fragments were amplified by PCR with degenerate oligonucleotide primers derived from the amino acid sequence conserved in the Cu/Zn-SOD from several other organisms. A partial cDNA of CuZn-SOD was obtained for R. decussates (510 bp), D. polymorpha (510 bp) and B. azoricus (195 bp). The deduced amino acid sequence showed high similarity among the three mollusc species (57-63%) and among other species (50-65%). The residues involved in coordinating copper (His-47, 49, 64, 121) and zinc (His-64, 72, 81 and Asp-84) were well conserved among the three Cu/Zn-SOD sequences. 相似文献
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用高效液相色谱法对2010年9月南黄海33个站位表层海水中总水解氨基酸(THAA)、溶解游离氨基酸(DFAA)、溶解结合氨基酸(DCAA)的分布、组成以及它们与环境因子的相关性进行了研究。结果表明:THAA平均浓度为2.08μmol/L,DFAA平均浓度为0.39μmol/L,DCAA平均浓度为1.69μmol/L。THAA浓度的分布大致呈近岸高、远岸低的特点;DFAA分布的规律性较差,在东部海域(中心约在35°N,123°E)出现高值。相关性分析显示溶解氨基酸与叶绿素a(Chl-a)、溶解无机氮(DIN)、细菌丰度、温度和盐度之间均无显著相关性。THAA中含量较高的个体氨基酸为丝氨酸、甘氨酸、天门冬氨酸、谷氨酸和丙氨酸,总和占70.59%。DFAA、DCAA中的主要成分与THAA基本相同。THAA中个体氨基酸的组成以34°N为界分为南北2个海区呈现明显的区域性特点。 相似文献