聚丙烯酰胺肟-羧酸螯合纤维对多种微量元素富集性能及机理的研究

近年来,利用巯基及它种螯合基纤维素富集测定多种微量元素的研究报导较多,但将螯合基团接在合成纤维上作为富集剂的报导尚少。我们曾用腈纶为原料合成聚丙烯酰胺肟-羧酸螯合纤维富集测定过数种微量元素。本文较系统地研究了该螯合纤维对30余种微量元素的定量富集酸度、吸附速度、洗脱酸度、饱和吸附量和共存离子的干扰,讨论了螯合纤维的稳定性、耐酸碱性、再生使用和富集机理,并进行了低浓度元素的富集和样品分析。实验表明,该螯合纤维是一种良好的高分子富集剂,它可以定量富集多种微量元素,具     

富集微量元素的食品

目前被大多数人认可的14种人体必需微量元素是人体生命的必需微量营养素,如果不足或缺乏,人体就会发育迟缓或不良,机能减弱甚至生病。人们都很清楚若要保持身体必需微量元素的相对平衡,就要保证正常的饮食平衡,甚至要吃一些富集必需微量元素食品,这些富集必需微量元素的食品原来是自然生长或野生的,但现在有一部份是科学技术人员种植和培育的。一、种芽食品:黄豆芽、绿豆芽、红豆芽等的萌芽至发芽期间,可以很快富集必需微量元素,大约3~5 d即可完成富集。铬元素是具有降血糖降血脂作用的必需微量元素,但日常一般食品中含铬极少,开发富铬食品是解决食品缺铬的一个方向。豆类营养价值高,发芽时营养成分发生变化,很快就能转化为被人体吸收利用的营养成分,通过生物转化可将不容易吸收的无机元素铬变成容易吸收的有机结合的元素铬。二、茸菌食品:灵芝、香菇、平菇、木耳等类已较多用于富集必需微量元素,尤其利用灵芝的抗癌功能与硒抗肿瘤功效,将两者结合起来发挥协同作用是再理想不过了。还有香菇、平菇及木耳富集必需微量元素的产品,已有许多地方面市,以上茸菌类食品都具有提高身体免疫力,抗肿瘤等诸多功能,是今后富集必需微量元素食品生产发展的重点。三、禽蛋产品:在家禽饲料...     

聚乙烯乙二胺丙酰胺肟大孔螯合树脂的合成及其富集分离微量元素的应用研究

本文以大孔聚氯乙烯树脂为原料,合成聚乙烯乙二胺丙酰胺肟螯合树脂,建立了利用该螯合树脂富集分离20余种微量元素的ICP化学光谱法,讨论了其富集各待测元素的性能和机理,进行了螯合树脂的红外光谱等结构分析及样品中微量元素的富集和测定,结果较满意。     

伊敏褐煤中微量元素的地球化学特征及其无机-有机亲和性分析

采用脱矿物质、提取腐殖酸等方法结合ICP-MS对伊敏15_上、16_下煤中的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。     

聚胺-聚脲螯合纤维的合成及性能研究——ICP化学光谱测定应用

利用螯合吸附剂从溶液中将金属离子进行选择性吸附,富集分离的方法已有文章详述。近年来用巯基棉及聚丙烯酰胺肟-羧酸螯合纤维富集多种微量元素的性能,机理研究及测试报道不少。本文利用氯纶为原料合成聚胺-聚脲螯合纤维,研究了在pH=5微酸性介质条件下,对铬、钛、钒、镓、铟、铅、锡等微量元素的富集性能进行了研究。此螯合纤维可定量吸附多种微量元素,具有富集倍数高,饱和吸附容量大,解脱性能及选择性好等特点,与ICP光谱测定结合,样品分析得到较满意的结果。     

乙二胺改性聚氯乙烯大孔螯合树脂富集分离微量金, 铂, 钯, 铱的性能和机理研究

本文利用ICP化学光谱法对自合成的聚乙烯乙二胺大孔螯合树脂富集分离微量金、铂、钯、铱进行了研究。讨论了螯合树脂对各微量元素的富集性能、吸附速率和富集机理,并进行了样品的分析,获得了较满意的结果。     

乙二胺改性聚氯乙烯大孔螯合树脂富集分离微量金, 铂, 钯, 铱的性能和机理研究

本文利用ICP化学光谱法对自合成的聚乙烯乙二胺大孔螯合树脂富集分离微量金, 铂, 钯, 铱进行了研究, 讨论了螯合树脂对各微量元素的富集性能、吸附速率和富集机理, 并进行了样品的分析, 获得了较满意的结果。     

煤中微量元素在燃烧过程中的变化

在分析微量元素燃烧过程中迁移变化机理的基础上,对电厂用煤和煤灰进行了采样测试,分析了电厂燃煤过程中微量元素的析出变化及在各种灰中的分布富集规律,同时用五个不同的温度段分别对煤进行了燃烧实验,研究了在不同温度下,微量元素从煤中析出的浓度和析出率,通过实验分析,。多数有害微量元素在飞灰中的富集浓度高于其它灰中,燃烧时温度的高低是影响微量的高低是影响微量元素迁移析出的重要因素,温度越高,有害微量元素析出率相对越大。     

电感耦合等离子体质谱研究洪湖湿地沉积柱中元素纵向分布

采集洪湖湿地两个具有代表性的湖底沉积柱进行对比,应用电感耦合等离子体质谱（ICP—MS）考察了沉积柱中微量元素及稀土元素的纵向分布特征。不同簇类的微量元素在两个沉积柱中呈现不同的纵向分布特征,微量元素富集层位存在明显的差异,表明沉积柱中微量元素的富集与沉积环境相关,直接受长江水流和交换影响的沉积柱（S1）比受洪湖湿地自身演变影响的沉积柱（S2）有更接近表层的富集层位。两个沉积柱纵向的稀土元素配分曲线呈现相似的分布特性,但分散程度不同,表明其具有相同的物源、不同的沉积环境。沉积柱中微量元素及稀土元素的纵向分布特征可以直接记录人类现代工农业活动对洪湖湿地的影响。     

面包酵母对微量元素富集作用的研究

微量元素在维持生命的正常代谢过程中起着重要作用[1-12].但无机微量元素不但毒性较大,且以极低水平吸收,有机微量元素吸收迅速且安全,因此,利用工业微生物,尤其以酵母为载体富集微量元素,使微量元素由无机态转为有机态,以提高其生物利用度,已成为国内外研究重点.而且通过一定载体改变其化学状态,还能够确保适度含量,对医学防治具有更重要的意义.本文通过生物富集得到以氨基酸络合物等有机形式存在的微量元素,利于人体吸收利用.     

Cleansing contaminated seawaters using marine cyanobacteria: evaluation of trace metal removal from the medium

The use of microbial biomass in biosorption is already being studied as a potential alternative to (or combined with) conventional processes, where several algae and microorganisms have already shown promising ability to uptake metals. Cyanobacteria (blue-green algae) are widespread organisms, with specific properties, such as high nutrient removal capacity and tolerance to highly variable conditions which make them well-suited for wastewater and remediation purposes. The main aim of this work was to evaluate the use of a marine cyanobacterium LEANCYA 21 (Synechocystis sp.), collected from the Portuguese southern border, for the removal of selected trace metals when in natural seawater culture medium. It was observed, for the first time, that this particular strain is capable of uptaking Pb, Ni and Zn (at nM levels) from seawater solutions using small amounts of biomass. Uptake values for Pb were up to 90% (0.75 mg g^?1 biomass) in 6 h. The specific biosorption curves of Ni and Zn showed that these metals follow a first order kinetics biosorption in batch conditions. Solutions containing multimetals have revealed that Ni uptake is affected by the presence of Pb and Zn. The calculated specific absorption values were high enough to predict a possible application in aquaculture where such low levels of metals may inhibit microalgae growth.     

Comparative Study of Biosorption of Heavy Metals Using Living Green Algae Scenedesmus quadricauda and Neochloris pseudoalveolaris: Equilibrium and Kinetics

The biosorption of several heavy metals such as cobalt(II), chromium(III), lead(II), cadmium(II), nickel(II), and manganese(II) from aqueous systems on living microalgae cultures, Scenedesmus quadricauda and Neochloris pseudoalveolaris were studied under laboratories conditions. The kinetic and statistical parameters were calculated by using the data obtained from batch cultivation and well fitted a pseudo-first-order rate equation. The initial metal concentrations in solution were about 5–40 mg · L^?1. According to the pseudo-second-order model, the biosorption capacities of Scenedesmus quadricauda for Co(II), Cr(III), Pb(II), Cd(II), Ni(II), and Mn(II) ions were found in the ranges of 2.14–52.48, 1.98–81.98, 8.05–4.26, 7.81–24.96, 2.17–55.71, and 3.54–75.20 mg g^?1, respectively. Kinetic studies revealed that the metal uptake capacity of each living green algae was rather fast. It was also observed that the biosorption kinetic rate decreased with increasing concentration for both microalgae. The application of diffusion-controlled models to the experimental results indicated that the contribution of intraparticle diffusion to the overall sorption kinetics was not very important. Results showed that Co(II), Cr(III), Pb(II), Cd(II), Ni(II), and Mn(II) ions could effectively be absorbed by using living microalga cultures from aqueous solutions.     

Using ICP-OES and SEM-EDX in biosorption studies

We have compared the analytical results obtained by inductively coupled plasma optical emission spectroscopy (ICP-OES) and by scanning electron microscopy with an energy dispersive X-ray analytical system (SEM-EDX) in order to explore the mechanism of metal ions biosorption by biomass using two independent methods. The marine macroalga Enteromorpha sp. was enriched with Cu(II), Mn(II), Zn(II), and Co(II) ions via biosorption, and the biosorption capacity of alga determined from the solution and biomass composition before and after biosorption process was compared. The first technique was used to analyze the composition of the natural and metal-loaded biomass, and additionally the composition of the solution before and after biosorption. The second technique was used to obtain a picture of the surface of natural and metal ion-loaded macroalgae, to map the elements on the cell wall of dry biomass, and to determine their concentration before and after biosorption. ICP-OES showed a better precision and lower detection limit than EDX, but SEM-EDX gave more information regarding the sample composition of Enteromorpha sp. Both techniques confirmed that biosorption is a surface phenomenon, in which alkali and alkaline earth metal ions were exchanged by metal ions from aqueous solution.FigureThe advantages and disadvantages of ICP-OES and SEM-EDX techniques ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00604-010-0468-0) contains supplementary material, which is available to authorized users.     

Saccharification of marine microalgae using marine bacteria for ethanol production

The saccharification of marine microalgae using amylase from marine bacteria in saline conditions was investigated. An amylase-producing bacterium, Pseudoalterimonas undina NKMB 0074 was isolated and identified. The green microalga NKG 120701 was determined to have the highest concentration of intracellular carbohydrate and was found from our algal culture stocks. P. undina NKMB 0074 was inoculated into suspensions containing NKG 120701 cells and increasingly reduced suspended sugars with incubation time. Terrestrial amylase and glucoamylase were inactive in saline suspension. Therefore, marine amylase is necessary in saline conditions for successful saccharification of marine microalgae.     

Insight into Potential Anticancer Activity of Algal Flavonoids: Current Status and Challenges

Flavonoids are some of the most precious phytochemicals, believed to be found largely in terrestrial plants. With the advancement of phytochemical research and marine bioprospecting, flavonoids have also been reported by the research of microalgae and macroalgae. High growth rate with minimal nutritional and growth requirement, saving arable land and rich metabolic profile make microalgae an excellent repertoire of novel anticancer compounds, such as flavonoids. In addition, marine algae, especially seaweeds contain different types of flavonoids which are assumed to have unique chemical structures and bioactivities than their terrestrial counterparts. Flavonoids are not only good antioxidants but also have the abilities to kill cancer cells by inducing apoptosis and autophagy. However, the study of the anticancer properties of flavonoids is largely limited to terrestrial plants. This review offers an insight into the distribution of different classes of flavonoids in eukaryotic microalgae, cyanobacteria and seaweeds with their possible anticancer activities. In addition, extraction and purification methods of these flavonoids have been highlighted. Finally, prospects and challenges to use algal flavonoids as anticancer agents have been discussed.     

Energy dispersive X-ray fluorescence analysis of marine pollution indicators

The present work shows a methodology for the application of EDXRF with a X-ray tube, in the analysis of elements in the following matrices: microalgae, marine algae, marine sediments and corals. Various methods were applied: one using a relative external standard, a fundamental parameters method, an absolute method based on elemental sensitivity, a method which used X-ray fluorescence excitation measured in the back side of the sample for low contents heavy elements determination and a TRXRF method. The thin layer samples were prepared using a plastic resin. The analyzed samples of marine algae, marine sediments and corals belong to a marine ecosystem from the North of Havana City, the most affected area by natural metereological phenomena and human impact.     

The effect of increase in concentration of Na(I) ions on biosorption of Cr(III) ions by Enteromorpha prolifera and Spirulina sp

In this study, the effect of the increase in the initial concentration of Na(I) ions in the solution during biosorption of Cr(III) ions by two edible algae: marine macroalga — Enteromorpha prolifera and microalga — Spirulina sp. was investigated. During biosorption, essential elements are exchanged with alkali and alkaline earth metal ions (e.g. Na(I) ions), which are naturally bound with the biomass. The goal of this study was to investigate the effect of the increase in concentration of Na(I) ions on biosorption performance. The equilibrium of the process is described by Langmuir equation. It was found that with the increase in the initial concentration of NaCl (from 132 to 7331 mg L^?1), there was a lower biosorption capacity of Enteromorpha prolifera (from 85.8 to 51.0 mg g^?1) and Spirulina sp. (74.2 to 20.7 mg g^?1) towards Cr(III) ions. It was also possible to determine the number of times the solution used in the biosorption process can be recycled and yet mantain high biosorption capacity. The determined numbers were: 16 for Enteromorpha prolifera and 19 for Spirulina sp.      

Suitability of Novel Algal Biomass as Fish Feed: Accumulation and Distribution of Omega-3 Long-Chain Polyunsaturated Fatty Acid in Zebrafish

Applied Biochemistry and Biotechnology - A 28-day feeding experiment with formulated feed using docosahexaenoic acid (DHA)-rich whole cells of freeze-dried marine microalgae Schizochytrium sp. to...     

自然水体生物膜有机组分对Pb(2+)的吸附特性及其影响因素

生物膜在天然水环境和工程处理中起着重要的作用．关于自然水体生物膜对重金属的吸附作用已有很多报道．但多数报道认为，生物膜中的无机物即铁锰氧化物对重金属的吸附起着主要作用，而对于生物膜的重要组成部分——有机组分对重金属吸附影响的研究则很少．     

Applications of Thermal Analysis on the Marine Phytoplankton,Tetraselmis Suecica

Marine microalgae represent an essential link in the planktonic food web and some of them are commonly utilised in aquaculture systems as food for larval and juvenile stages of fishes, crustacea and mollusca. However, the caloric content and the biochemical composition of these microrganisms vary in relation to ageing and to several environmental conditions; so if the parameters under which phytoplankton grow are not suitable, marine microalgae can supply small quantities of energy and essential nutrients. The aim of this work was to study the effects of temperature on the marine planktonic alga Tetraselmis suecica using thermogravimetry (TG) and differential thermal analysis(DTA). Marked differences have been observed between exponentially, stationary and senescence phases probably due to both the presence of different biomolecules produced during algal growth and to the differences in the thermal properties of these intracellular molecules. This revised version was published online in July 2006 with corrections to the Cover Date.