I^——EDTA—Cu^2＋体系在分析化学中的应用

本文采用Ｐｔ／Ｉ２／Ｉ＾－电极电位滴定法，系统地研究了，Ｉ＾－－ＥＤＴＡ－Ｃｕ＾２＋体系在不同条件下的化学平衡，提出了用Ｃｕ＾２＋盐返滴法和Ｎａ２Ｓ２Ｏ３滴定法测定Ｎｉ＾２＋、Ｓｎ＾４＋等金属离子的新方法，为多元素（如Ｃｕ－Ｓｎ、Ｃｕ－Ｎｉ、Ｃｕ－Ｎｉ－Ｆｅ等）连续测定提供了新途径。     

液膜法分离富集测定钢中痕量铅

用２，６－二酮吡啶－１８－王冠－６（２－６－ＤＫＰ－１８－Ｃｒｏｗｅ－６），ＳＰＡＮ８０，Ｓ１００Ｎ－Ｉ（中性油）和Ｃ２Ｈ２Ｃｌ４乳状液膜体系，研究了Ｐｂ６２＋的迁移行为。在适宜条件下，８ｍｉｎ内Ｐｂ＾２＋的迁移率达９９．５％以上，而而这种情况下，许多金属离子如Ｆｅ＆３＋，Ｎｉ＾２＋，Ｃｒ＾３＋，Ｌｉ＾＋，∑ＲＥ＾３＋，Ｋ＾＋，Ｎａ＾＋，Ｃａ＾２＋，Ｍｇ＾２＋，Ｂａ６２＋，Ｓｒ＾２＋，Ａｌ＾３＋，     

二甲酚橙分光光度法测定锡、铁、铝

在ｐＨ＜６．３的溶液中,二甲酚橙（ＸＯ）与某些金属离子Ｍｅ,如Ｔｈ４＋,Ｂｉ３＋,Ｐｂ２＋,Ｚｎ２＋,Ｈｇ２＋,Ｃｄ２＋等生成的红色络合物Ｍｅ－ＸＯ的稳定性小于ＥＤＴＡ（Ｈ２Ｙ２－）与Ｍｅ生成的络合物ＭｅＹ。Ｓｎ４＋,Ｆｅ３＋,Ａｌ３＋,Ｃｒ３＋,Ｎ...     

动力催化—离子选择电极法测定痕量金的研究及应用

研究了一种以金为催化剂，以铁氰化钾与ＥＤＴＡ之间的配位取代反应为指示反应，以邻菲罗啉为活化剂的新的动力学催化剂。此法用氰电极监测反应中释放出来的氰化物，其量与５×１０＾－９－－４×１０＾－６ｍｏｌ／Ｌ范围内的金的浓度成正比。方法的选择较高，Ｓｂ＾３＋、Ｍｏ（Ⅵ）、Ｃｕ＾２＋、Ｃｏ＾２＋、Ｃｄ＾２＋、Ｆｅ＾３＋Ｃｒ（Ⅲ）、ＮＯ３、ＣＬ等２５种离子不干扰测定，主要干扰离子有Ｐｔ＾４＋、Ａｇ＋、Ｈｇ＾２     

电位滴定法连续测定钴、镍和铜的方法研究（Ⅱ）

本文以Ｐｔ电极作指示电极,Ｗ电极作参比电极,在氨性介质中,以Ｋ＿３Ｆｅ（ＣＮ）＿６滴定Ｃｏ￣（２＋）以后,继而利用Ｆｅ（ＣＮ）／Ｆｅ（ＣＮ）作指示离子,在ｐＨ５．５～６．０,用Ｚｎ￣（２＋）返滴定ＥＤＴＡ,连续测定Ｎｉ￣（２＋）或Ｎｉ￣－Ｃｕ含量,再用硫酸肼作Ｃｕｙ￣（２－）的释放剂,Ｚｎ￣（２＋）返滴定释放出的ＥＤＴＡ测定Ｃｕ￣（２＋）,实现了Ｃｏ－Ｎｉ－Ｃｕ连续测定。镍精矿样分析的相对标准偏差和试样中标准回收率分别为Ｃｏ：１．４％,９９．５±１．２％。Ｎｉ：１．１％,１００．１±０．９％。Ｃｕ：２．０     

选择性螯合滴定法测定镍的含量

本文提出分别氟化物，草酸（草酸盐）和Ｎａ４Ｐ２Ｏ７掩蔽Ｆｅ＾３＋，Ａｌ＾３＋，Ｓｎ＾４＋，Ｚｒ＾４＋，Ｔｉ＾４＋，Ｎｂ＾５＋，∑ＲＥ＾３＋和Ｍｎ＾２＋等（一般常见金属离了，不干扰）用ＥＤＴＡ螯合Ｎｉ＾２＋，以ＣＸ（苏木精），ＰＡＲ（４－（２－Ｐｙｒｉｄｙａｚｏ）ｒｅｓｏｒｃｉｎｏｌ）ＭＧ（孔雀绿）为混合指标剂，用Ｃｕ＾２＋标准溶液返滴定法测定合金钢和镍精矿中的镍，终点颜色变化格外敏锐，清晰，实践表     

冶金产品中Co（Ⅲ）的测定方法研究

提出了在Ｈ２ＳＯ４介质中,加入定量的ＦｅＳＯ４．（ＮＨ４）２ＳＯ４作为Ｃｏ＾３＋的还原剂,通过测定过量的Ｆｅ＾２＋而间接地测定Ｘｏ＾３＋。讨论了介质、还原剂、浸取手段、酸度、浸出时间、还原剂的浓度及干扰离子等因素对测定结果的影响。方法操作简便、快速。对高含量的Ｃｏ＾３＋的测定,效果尤佳。     

液膜分离富集CN^—与测定水中氰化物

用ＴＢＰ－ＰＭＢＰ、ＳＰＡＮ８０、液体石蜡、煤油和内相（２％ＮａＯＨ溶液）乳状液膜，研究了ＣＮ＾－的迁移行为及最适宜的实验条件。ＣＮ＾－在１５ｍｉｎ内可以迁移９９．５％以上。在此情况下许多共存离子，如Ｍｏ＾６＋、Ｍｏ＾５＋、Ｆｅ＾３＋、Ａｌ＾３＋、Ｃａ＾２＋、Ｍｇ＾２＋、Ｓｒ＾２＋、Ｂａ＾２＋、ΣＲＥ＾３＋、Ａｇ＾２＋、Ｐｄ＾２＋、Ｐｔ＾４＋、Ｒｈ＾３＋、Ｃｕ＾２＋、Ｐｂ＾２＋、Ｚｎ＾２＋、Ｗ＾６     

铜精矿中金属元素的快速分析法

本文应用Ｐｔ／Ｉ２／Ｉ＾－为指示电极，以Ｎａ２Ｓ２Ｏ３为滴定剂，连续测定了铜精矿中Ｃｕ－Ｆｅ－Ｎｉ。文章重点研究了在Ｃｕ＾２＋、Ｆｅ＾３＋、Ｎｉ＾２＋、Ｃｏ＾２＋、Ａｌ＾３＋、Ｉ＾－、ＥＤＴＡ共存的复杂体系中测定Ｎｉ＾２＋的条件，以及用Ｐｔ／Ｉ２／Ｉ＾－电极连续指示滴定终点的原理和实验条件。     

用XO—TPB作批示剂测定石灰石中的钙,镁

采用加入表面活性剂溴化十四烷基吡啶（ＴＰＢ），用乙二胺四乙酸（ＥＤＴＡ）滴定的方法测定石灰石中的Ｃａ＾２＋，Ｍｇ＾２＋。试验表明，在ｐＨ值为１０．５的ＮＨ３·Ｈ２Ｏ－ＮＨ４Ｃｌ缓冲溶液中进行滴定，终点时溶液的颜色出紫红色变为无色（或极浅的灰色），使终点观察十分敏锐。     

氯化钠-硫氰酸铵-正丙醇-水体系中铁（Ⅲ）的析相萃取分离和富集研究

研究了氯化钠-硫氰酸铵-正丙醇-水体系析相萃取分离和富集铁的行为及铁与一些金属离子分离的条件。结果表明,氯化钠能使正丙醇的水溶液分成两相,在分相过程中,Fe（Ⅲ）和NH4SCN生成的［Fe（SCN）4~6］［（4~6）-3］-与质子化正丙醇C3H7OH2+ 形成的缔合物［Fe（SCN）4-6］［ C3H7OH2］1-３能被正丙醇相完全萃取。当溶液pH值为3,正丙醇的体积分数、NH4SCN溶液的浓度和氯化钠溶液的质量浓度分别为30 %,7.0×10-2 mol/L和0.2 g/mL时, Fe（Ⅲ）的萃取率达到97.5%以上,而W(Ⅵ),Ag（Ⅰ）,Ce（Ⅲ）,Cr（Ⅲ）,Mn（Ⅱ）,Cd（Ⅱ）,Al（Ⅲ）,Ni（Ⅱ）,Ga（Ⅲ）和Mg（Ⅱ）基本不被萃取,实现了Fe（Ⅲ）与上述金属离子的分离。对合成水样和镍铬铝合金中Fe（Ⅲ）进行分离和测定,结果满意。该萃取体系可以用作微量铁的分离和富集,在分析中具有实用价值。     

EDTA络合滴定法测定钼铁中的钼

本文研究了在一定酸度下，利用乙二胺四乙酸二钠盐，对钼铁中钼元素的络合滴定分析方法，在干扰元素Ｗ含量较高时，Ｍｏ的测定进行了探讨，该方法用于一般厂生产的相铁，和加入高工钢铁鳞，金属热法生产的钼铁的分析，获得了较为满意的结果。     

Reaction paths of iron oxidation and hydrolysis in horse spleen and recombinant human ferritins

UV-visible spectroscopy, electrode oximetry, and pH stat were used to study Fe(II) oxidation and hydrolysis in horse spleen ferritin (HoSF) and recombinant human H-chain and L-chain ferritins (HuHF and HuLF). Appropriate test reactions and electrode responses were measured, establishing the reliability of oxygen electrode/pH stat for kinetics studies of iron uptake by ferritin. Stoichiometric ratios, Fe(II)/O2 and H+/Fe(II), and rates of oxygen uptake and proton production were simultaneously measured as a function of iron loading of the protein. The data show a clear distinction between the diiron ferroxidase site and mineral surface catalyzed oxidation of Fe(II). The oxidation/hydrolysis reaction attributed to the ferroxidase site has been determined for the first time and is given by 2Fe2+ + O2 + 3H2O --> [Fe2O(OH)2]2+ + H2O2 + 2H+ where [Fe2O(OH)2]2+ represents the hydrolyzed dinuclear iron(III) center postulated to be a mu-oxo-bridged species from UV spectrometric titration data and absorption band maxima. The transfer of iron from the ferroxidase site to the mineral core has been now established to be [Fe2O(OH)2]2+ + H2O --> 2FeOOH(core) + 2H+. Regeneration of protein ferroxidase activity with time is observed for both HoSF and HuHF, consistent with their having enzymatic properties, and is facilitated by higher pH (7.0) and temperature (37 degreesC) and by the presence of L-subunit and is complete within 10 min. In accord with previous studies, the mineral surface reaction is given by 4Fe2+ + O2 + 6H2O --> 4FeOOH(core) + 8H+. As the protein progressively acquires iron, oxidation/hydrolysis increasingly shifts from a ferroxidase site to a mineral surface based mechanism, decreasing the production of H2O2.     

配合物NH4[Ln（H2O）9][（VⅣO）2（μ2-O）（nta）2]（Ln=Sm,Y）的合成及钐配合物的晶体结构

在水溶液中合成了两个钒-稀土配合物NH4[Ln(H2O)9][(VIVO)2(μ2-O)(nta)2](Ln=Sm,Y),其中钒-钐配合物为单晶体,钒-钇配合物为多晶态粉末。单晶X-射线衍射分析表明,钒-钐配合物属单斜晶系,C2/c空间群,晶胞参数a=2.336(4),b=1.0907(9),c=1.0823(10)nm,β=93.21(2)°,V=2.753(6)nm3,Z=4。配合物包含了一个二核的钒阴离子[(VIVO)2(μ2-O)(nta)2]4-(H3nta=氨三乙酸)和一个九配位的钐阳离子[Sm(H2O)9]3+,两者通过氢键连接成三维超分子结构。     

The effect of ulinastatin on CFU-C colony formation in mouse myelocyte cultures

The mixture of 5'-guanylylimidodiphosphate (Gpp(NH)p)/EDTA/NaCl has been used to delineate low-affinity conditions for agonists binding to G-protein-linked receptors. The effects of this mixture on [3H]RX821002 (2-methoxyidazoxan) binding to alpha2-adrenoceptors were evaluated in different tissues. The density of alpha2-adrenoceptors in the presence of the mixture was 11, 78 and 60% higher in human cortex (predominant alpha2A), human caudate (alpha2A + alpha2C) and rat kidney (alpha2A + alpha2B), respectively, than in its absence. In rat kidney, masking of alpha2B-adrenoceptors by ARC239 (2-[2-[4-(o-methoxyphenyl)-piperazin-1-yl]-ethyl]-4,4-dimethyl-1,3 -(2H,4H)-isoquinolindione) (50 nM) or masking of alpha2A-adrenoceptors by BRL44408 (2-[2H-(1-methyl-1,3-dihydroisoindole)methyl]-4,5-dihydroimidaz ole) (100 nM) demonstrated that the increase was in the alpha2B-adrenoceptor but not in the alpha2A-adrenoceptor subtype.     

Kinetics of the competitive degradation of deoxyribose and other biomolecules by hydroxyl radicals produced by the Fenton reaction

The objective of this work is to reexamine the competitive degradation of deoxyribose by hydroxyl radicals (.OH) produced by the reaction between H2O2 and Fe(2+)-EDTA. The .OH radicals produced attack deoxyribose (D, rate constant kD) and eventually an .OH scavenger (S, rate constant kS). First, we examined the effect of [D], [H2O2], [Fe(2+)-EDTA], [EDTA]/[Fe2+] ratio and reaction time on the rate of D degradation, measured as the absorbance of the chromogen formed between the product of the reaction D + .OH (malondialdehyde) and thiobarbituric acid. In particular, it was showed that under our experimental conditions ([D] = 3 mM, [H2O2] = 0.85 mM, [Fe2+] = 0.13 mM), the rate of overall process is first order in Fe2+, zero order in H2O2 and is maximal for a ratio [EDTA]/[Fe2+] = 1.1. Second, the kinetics of .OH radical reaction in competition experiments between D and S (mannitol) was investigated. The results show that the ratio of the rates of D degradation in the absence (VD) and in the presence (VDS) of S should be represented by VD/VDS = 1 + ks[S]/(kD[D] + kx) where kx accounts for the rate of .OH reactions with other reagents such as Fe(2+)-EDTA, H2O2 etc . . . After having determined kx for each set of experimental conditions, we obtained the values of kS/kD by determining the variations of VD/VDS as a function of [S] and [D]. By taking kD = 1.9 x 10(9) M-1s-1 a value of kS = 1.9 x 10(9) M-1s-1 was obtained, very close to that obtained by pulse radiolysis. Finally, the validity of the established relation was confirmed for other biomolecules (methionine, k = 5.6 x 10(9)M-1s-1 and alanine, k = 3.3 x 10(8) M-1s-1). By contrast, it was not applicable to cysteine, thiourea and mercaptoethanol which was attributed to an interaction of the latter scavengers with Fe2+ and/or H2O2.     

硫氰酸盐法从含铜黄铁矿焙砂中浸金研究

对用Ｆｅ３＋作氧化剂，ＳＣＮ－作络合剂，从含铜黄铁矿焙砂中提取黄金的工艺条件进行了研究。理论分析和实验结果都证明了该工艺在技术上是可行的。利用了黄铁矿焙砂中的Ｆｅ２Ｏ３经酸分解后而产生的Ｆｅ３＋作氧化剂，可不必再加其它的氧化剂，同时脱铜后又可降低硫氰酸铵的耗量。本工艺还具有设备简单、毒性小、周期短、综合利用程度高等优点。     

硅钙合金中硅钙联合测定

试样用NaOH、Na2O3混合熔剂熔融，用稀盐酸浸出，在硫酸介质中，用硅钼蓝光度法测定硅，用氨水沉淀分离铁、铝等杂质，用EDTA容量法测定钙。该方法用于硅钙合金中硅钙联合测定，方法简便，稳定。     

纳米氧化铁的制备及形貌分析

以九水硝酸铁（Fe（NO₃）₃·9H₂O）为铁源,无水乙醇和乙二胺为表面活性剂,采用水热法制备了纳米氧化铁（Fe₂O₃纳米棒）,通过扫描电子显微镜观察分析了Fe₂O₃纳米棒形貌,研究了（Fe（NO₃）₃·9H₂O）质量分数及反应温度对Fe₂O₃纳米棒颗粒尺寸的影响。结果表明,纳米棒的长度和宽度分别约为500～600 nm和50～60 nm;在160～220 ℃范围内,温度对Fe₂O₃纳米棒形貌的影响不显著;在一定范围内提高铁源质量分数可使纳米棒颗粒尺寸变小。Fe₂O₃纳米棒的形成机理为:铁源在强碱性的溶液中反应生成棕黄色絮状沉淀α-FeOOH,该沉淀在高温高压的环境中,在乙二胺作用下脱水形成Fe₂O₃纳米棒。     

Hydrodechlorination of Chlorinated Ethanes by Nanoscale Pd/Fe Bimetallic Particles

Chlorinated ethanes are contaminants commonly found in soil and groundwater. The potential of nanoscale bimetallic (Fe/Pd) particles for the hydrodechlorination of seven chlorinated ethanes (C2H6?xClx) was evaluated in batch experiments. Hexachloroethane (HCA) (C2Cl6), pentachloroethane (PCA) (C2HCl5), 1,1,2,2-tetrachloroethane (1,1,2,2-TeCA, C2H2Cl4), and 1,1,1,2-tetrachlorethane (1,1,1,2-TeCA, C2H2Cl4) were rapidly hydrodechlorinated (9–28 min half-lives) at a nanoparticle loading of 5 g/L. End products were ethane (61–87%) and ethylene (6–16%). Only one chlorinated intermediate, a corresponding β-elimination product, appeared temporarily during the reactions. Reductive dechlorination of 1,1,1-trichloroethane (1,1,1-TCA, C2H3Cl3) to ethane was completed at a relatively slower rate with half-life at 44.9 min. Little reduction of dichloroethane (C2H4Cl2) was observed within 24 h. The Pd/Fe bimetallic nanoparticles generally exhibit much higher reactivity when compared with conventional micro- and millimeter scale iron powders. The hydrodechlorination reactions are more complete, with a much higher yield of ethane and lower yield of chlorinated byproducts. A kinetic model incorporating a transition state species was proposed. Results from this work suggest that the Pd/Fe bimetallic nanoparticles may represent a treatment alternative for in situ remediation of chlorinated ethanes.