重量法测定黄腐植酸含量

腐植酸类物质是一种天然的羟基羧酸,是由死亡植物分解而形成的一种暗黑色无定形物质,由碳、氢、氧、氮和少量硫、磷组成。腐植酸类物质由黄腐植酸(分子量300～400)、棕腐植酸(分子量2×103～2×104)和黑腐植酸(分子量1×104～1×106)组成。生产腐植酸的原料主要有泥煤、褐煤、木煤(柴煤)和风化煤等。腐植酸是一种内表面积很大的高分子有机物,吸湿性强(风干的腐植酸含水可达25%),具有吸附多种微量元素的能力。它同时具有酸性,可使碳酸盐、磷酸盐等分解。黄腐植酸在农业、制药方面有其重要的用途,因而其产品价格在腐植酸类物质中为最高。…     

腐植酸类物质的性质和应用

在伟大领袖毛主席关于“农业学大寨”的伟大号召下,全国各地为夺取农业丰收掀起了广开肥源的群众运动,制出了许多新化肥、土化肥。腐植酸类肥料就是其中一种。腐植酸类物质存在于土壤、泥炭、褐煤中,风化烟煤中有再生腐植酸,也可以用人工氧化煤的方法(如用空气、氧气、硝酸等作为氧化剂)制得再生腐植酸。用硝酸氧化制得的称硝基腐植酸。一般人们把从土壤、泥炭、褐煤中用碱(通常用氢氧化钠)抽提出的一部分,称为腐植酸。     

低阶矿物制备腐植酸盐的开发及应用研究

腐植酸盐(HA)主要存在于低阶矿物(硅酸盐类、泥炭、褐煤和风化煤等矿物)中,本文作者介绍了从低阶矿物中提取HA盐的新工艺及在各行业的应用,并对我国未来低阶矿物和腐植酸盐领域的发展前景进行了展望.     

木质素活化及在木材胶粘剂中的应用进展

木质素是相对分子量较高的天然聚合物,由于具有苯酚结构利于制备木材胶粘剂,但是木质素本身反应活性低,一般都将其活化后再利用.而且,除了以往利用最多的造纸工业产生的木质素外,研究发现木材经过褐腐菌降解后残留主要成分是结构部分发生变化的木质素,这种可再生生物质资源以其自身的结构特点在合成胶粘剂上也有很大的优势,本文结合木质素胶粘剂应用中的问题,重点概述了活化木质素的各种方法及褐腐木质素在木材胶粘剂中的应用.     

硝酸氧解法提高泥炭中黄腐酸的产率

硝酸氧解法提高泥炭中黄腐酸的产率;腐植酸;硝酸氧化降解     

风化煤黄腐酸的凝胶分级及结构特征

风化煤中含有丰富的黄腐酸(以下称 FA)。近年来在工农业上一直进行着应用方面的研究。作为药物,对多种疾病都有显著疗效,引起了人们的注意。腐植酸类物质是一种分布广泛的天然化合物,已有近二百年的研究历史,至今尚无公认的化学结构。很多人对土壤 FA 进行了各种分级方法的研究,但目     

腐植酸铵肥料

腐植酸铵,与小氮肥、小磷肥和磷矿粉肥一样,是我国劳动人民在独立自主、自力更生方针指导下,就地取材,大搞综合利用,发展起来的一种新的肥料品种。它具有良好的肥效和改良土壤的作用,而且原料广、生产方法简单、投资少、上马快。腐植酸是由碳、氢、氧、氮等元素组成的高分子混合物,难溶于水,显酸性,与强碱作用生成腐植酸盐,其钠盐和铵盐均易溶于水。土壤中有机质的主要成分是腐植质,而腐植酸就是腐植质的主要组成部分。天然的腐植酸除存在于土     

腐植酸比色法和容量法的改进

腐植酸是一组由植物残体经一系列分解而形成的复杂有机酸。其组成可分为黑腐酸,棕腐酸和黄腐酸,主要由碳、氢、氧、氮四元素组成,难溶于水,显酸性,与强碱或氨水作用生成易溶于水的腐植酸盐类,施入土壤中后,能改良土壤,提供养分,并能刺激植物生长,改善作物的素质,增加产量,因此,腐植酸类肥料是一种多功能,增产效果好的有机肥料。天然腐植酸主要存在于褐煤、草炭、风化煤中。我国资源丰富。贫下中农总结草炭的找矿标     

三苯基锗不饱和烃基酸衍生物的合成和性质

随着倍半锗氧类化合物的合成及应用研究的日益广泛 ,含 Ge_ O键的烃基锗衍生物的合成及应用也逐渐引起了人们的关注 .1 984年 ,L ukevics等 [1]合成了具有抗癌活性的介吗川类化合物 ,1 990年Kakimoto等 [2 ] 报道了具有杀菌活性的环状烃基羧酸的合成与应用 .但是三烃基锗的膦酸类衍生物的合成及生物活性研究均未见文献报道 .为了研究该类化合物的生理活性 [3～ 5] ,本文以三苯基氯化锗和炔基 (烯基 )膦酸钠为原料 ,在苯中反应 ,合成了一系列双 - O- (三苯基锗 )炔基 (烯基 )膦酸酯和单 - O-三苯基锗炔基 (烯基 )膦酸 ,部分化合物初步生理…     

疣孢菌NS0172产生的邻二烷基取代芳香酸

从疣孢菌NS0172的发酵产物中分离得到2个新的邻二烷基取代芳香酸类化合物1和2.通过一维和二维NMR数据解析及高分辨质谱分析确定了化合物1和2的化学结构.利用噻唑蓝(MTT)比色法测定了化合物1和2的细胞毒活性,结果显示化合物1对人肝癌细胞SMMC-7721具有一定的细胞毒性(IC507.74μmol·L^-1).利用滤纸片法测定了化合物1和2的抗细菌和抗真菌活性,结果显示两者在40μg/disc条件下均无抗菌活性.这是首次报道疣孢菌代谢产生邻二烷基取代芳香酸类化合物,为后续开展相关生物合成机制研究奠定了基础.     

腐殖酸自水溶液中吸附亚甲基蓝的热力学与机理研究

腐殖酸是自然界植物残体经腐解后的产物 ,为一种复杂的天然大分子有机质 ,分子内主要含有羰基、羧基、醇羟基、酚羟基等多种活性官能团 ,因此它具有弱酸性、亲水性、吸附性和络合性 ,能够与许多有机、无机物发生相互作用。腐殖酸能作为水处理过程中的吸附剂 ,研究它对水中各类污染物的吸附规律和机理是十分有意义的。赵振国等[1～ 3] 运用吸附过程的ΔＧ 、ΔＨ 、ΔＳ 等热力学函数的变化来探讨吸附机理 ,得出了一些有意义的结论。我们将这一方法应用到水溶液体系中 ,探讨在不同吸附条件下各吸附热力学函数的变化 ,以期对吸附过程有更进一…     

Screening of Humic Substances Extracted from Leonardite for Free Radical Scavenging Activity Using DPPH Method

Humic substances (HSs) have been researched for a long time and still manage to surprise humanity today. According to the latest research, in addition to their previously well-known effects, they also have antioxidant properties. However, this previous research does not examine the difference in the antioxidant effect of the fractions extracted/produced in different processes; they do not consider the light absorption of the HSs, which falsifies analysis based on the measurement of color change over time. In the present work, HS fractions were obtained from leonardite, the extraction processes can also be implemented on an industrial scale. The fractions were characterized by elementary analysis, UV–Vis and FT-IR spectroscopies, to prove that our self-extracted samples have similar characteristics to the International Humic Substances Society (IHSS) standard samples. The different methods of HS fractionation affected the elemental composition, and the spectral characteristics. The antioxidant effect was investigated using the DPPH method to screen the antioxidant efficiency of humic, fulvic, and himatomelanic acids. In addition, we compared our results with the IHSS standard samples to obtain a more comprehensive picture of the antioxidant effect of HSs extracted in different ways according to the DPPH method. Based on our results, the extraction method affects not only the physico-chemical properties but also the free radical scavenging activity of the fractions.     

The Effect of Supramolecular Humic Acids on the Diffusivity of Metal Ions in Agarose Hydrogel

Humic acids are known as natural substances of a supramolecular nature. Their self-assembly ability can affect the migration of heavy metals and other pollutants in nature. The formation of metal-humic complexes can decrease their mobility and bioavailability. This study focuses on metal ions diffusion and immobilization in humic hydrogels. Humic acids were purchased from International Humic Substances Society (isolated from different matrices—peat, soil, leonardite, water) and extracted from lignite mined in Czech Republic. Copper(II) ions were chosen as a model example of reactive metals for the diffusion experiments. The model of instantaneous planar source was used for experimental data obtained from monitoring the time development of copper(II) ions distribution in hydrogel. The effective diffusion coefficients of copper(II) ions showed the significant dependence on reaction ability of humic hydrogels. Lower amounts of the acidic functional groups caused an increase in the effective diffusion coefficient. In general, diffusion experiments seem to act as a valuable method for reactivity mapping studies on humic substances.     

Thermal characterization of humic acids and other components of raw coal

Over the ages, the deposits of dead vegetation buried by rock and mudflows, compacted and compressed out all of the moisture; it slowly carbonized and became coal. Humic acids are natural organic acids — brown coloured biological macromolecules, formed in coal by biochemical changes (decomposition, pyrolysis) of lignocellulosic matter. From lignite coal bed, the humates were extracted in alkaline medium and isolated from the residual fraction. Humic acids were obtained by treating humantes’ solutions with HCl. Thermal analysis (TG, DTG, DTA and DSC) was used in order to establish the decomposition and thermal effects of lignite, humates, humic acids and residual matter extracted from Rovinari mines in Romania. A non-isothermal linear temperature regime was imposed to reveal all decomposition steps.     

腐殖质与铀和超铀元素相互作用的研究进展

腐殖质是一类广泛存在于自然界中的高分子有机化合物,能与放射性核素相互作用,从而影响其在自然环境中的化学形态、迁移沉降、氧化还原行为等。本文介绍了目前国内外关于腐殖质与铀和超铀元素相互作用的研究现状和进展,并对存在的问题及今后的发展方向进行了初步讨论。     

The kinetics of thermo-oxidative humic acids degradation studied by isoconversional methods

Humic acids represent a complicated mixture of miscellaneous molecules formed as a product of mostly microbial degradation of dead plant tissues and animal bodies. In this work, lignite humic acids were enriched by model compounds and the model-free method suggested by Šimon was used to evaluate their stability over the whole range of conversions during the first thermooxidative degradation step. The kinetic parameters obtained were used to predict the stability at 20 and 180°C, respectively, which served for the recognition of processes induced by heat and those naturally occurring at lower temperatures. Comparison of the conversion times brought a partial insight into the kinetics and consequently into the role of individual compounds in the thermooxidative degradation/stability of the secondary structure of humic acids. It has been demonstrated that aromatic compounds added to humic acids, except pyridine, increased stability of humic acids and intermediate chars. The same conclusion can be drawn for acetic and palmitic acids. Addition of glucose or ethanol decreased the overall humic stability; however, the char of the former showed the highest stability after 40% of degradation.     

Role of fractionation in studying the photochemical properties of humic substances

The purpose of the cooperative research between laboratories of Pushchino Biological Centre Russian Academy of Sciences and Laboratoire de Photochimie Moléculaire et Macromoléculaire, CNRS, France was the investigation of photochemical properties of humic substance fractions with different molecular sizes and electrophoretic mobilities. Humic acids from five different soils were used. The resulting data showed that a great part of photosensitizing fluorophores and chromophores are located in low-molecular fractions of humic acids, independently of their source.     

腐植酸对丙烯酰胺溶液聚合的影响

<正> 六十年代以来,苏联发表了一系列文献,涉及乙烯基单体与腐植酸聚合制造土壤改良剂和钻井泥浆处理剂,但就一些基本问题未见阐述,诸如:(1)腐植酸中的多官能及含有的自由基对烯类单体自由基聚合的影响;(2)腐植酸与单体的接枝效率及腐植酸与单体接枝聚合机理;(3)接枝共聚物与共混物在性能上的差异,本文针对上述第一个问题进行了研究。采用膨胀计法研究了在不同类型煤炭腐植酸存在下,过硫酸钾引发丙烯酰胺溶液的聚合反应动力学。     

The Effects of a Strong Disaggregating Agent on Sec-Page of Aquatic and Soil Humic Matter

Abstract

Size-exclusion chromatographic (SEC) fractionation and electrophoretic separation of aquatic humic matter samples from a Finnish lake using Sephadex G-75 with 7 M urea solution as eluent and 10% polyacrylamide gel (PAGE) with urea and sodium dodecyl sulphate solution (SDS), respectively, were performed and compared to similar analyses performed on a Russian chernozem soil humic acid sample and Nordic reference fulvic and humic acid samples. The integrated whole of aquatic humic solutes and soil humic acids were found to exhibit similar SEC-PAGE behaviours. Humic matter was not excessively disaggregated by the 7 M urea and hence SEC-PAGE can with confidence be applied as a coarse, initial fractionation procedure or for certain predeterminations of the structural composition.