催化动力学光度法测定痕量铁(Ⅲ)──铁(Ⅲ)-甲基紫-过氧化氢体系

本文研究了硫酸介质中，铁（Ⅲ）催化过氧化氢氧化甲基紫的褪色反应，建立了分光光度法直接测定痕量铁（Ⅲ）的新方法，其灵敏度为4．0×10(-9)g·ml(-1)，测定铁（Ⅲ）的范围为0～0．70μg／25ml。方法简便、快速，分析费用低，可用于水样中痕量铁（Ⅲ）的测定。     

2-(5-溴-2-吡啶偶氮)-5-二甲氨基酚光度测定水中的痕量铁

<正> 常用于测定铁的经典方法如硫氰酸盐法、邻菲哕啉法和向红菲啰啉法,其灵敏度不高。Shibata 等首先提出用2-(5-溴-2-吡啶偶氮)-5-二甲氨基酚(简称5-Br-DMPAP)作为光度测定镍、钴、锌、铜和镉的试剂,但应用于铁的光度测定则尚未见报导。本文详细研究了铁(Ⅱ)与5-Br-DMPAP 在醋酸-醋酸盐缓冲介质中形成络合物的条件和组成及其光度性质。应用于水质分析中痕量铁的测定,具有高选择性和高灵敏度。     

离子浮选-分光光度法测定工业循环水中的痕量铁

提出用离子浮选-分光光度法测定工业循环用水的痕量铁,痕量铁测定的线性范围为0～50ug·mL-1.用本法绘制的标准工作曲线与用直接法显色绘制的标准工作曲线基本一致,相关系数r=O.9998,加标回收率96%～105%之间.用分光光度法测定工业循环水中的痕量铁,速度快,准确度和精密度较高,结果满意.     

浊点萃取-石墨炉原子吸收测定自来水样中的铁

建立了一种用于环境水样中痕量铁元素测定的方法。该方法通过浊点萃取对环境水样中痕量铁进行预富集分离,并与石墨炉原子吸收分光光度法联用进行检测,在最优化条件下,测定水中的痕量铁,RSD为2．06％,检测限为1．2×10^-2μg／L。     

1，10—邻二氮菲—苦味酸三元配合物分光光度法测定痕量跌

利用在醋酸-醋酸钠缓冲溶液（Ph4.6)中Fe^2 与1，10-邻二氮菲-苦味酸盐形成橙红色配合物的显色反应，建立了一种新的测定人发中痕量铁的分光光度法，用于正常人及患者头发中的痕量铁分析。     

新显色剂4-(6-溴-2-苯并噻唑偶氮)邻苯二酚-铁(Ⅱ)-OP 体系的分光光度研究

在pH 8.5～9.4的范围内,4-(6-溴-2-苯并噻唑偶氮)邻苯二酚(6-Br-BTAPC)与铁(Ⅱ)形成稳定的、带负电荷的紫色二元配合物。在 25℃、pH 9.0和μ0.1时,Fe(Ⅱ)-6-Br-BTAPC-OP 三元胶束配合物中 Fe(Ⅱ)与 6-Br-BTAPC 的组成比为1:3,表观稳定常数为7.7×10~(13),λ_(max)为635nm,对比度(△λ)95 nm,表观摩尔吸光系数ε_(635)高达1.23×10~5L·mol~(-1)·cm~(-1)。铁含量在0～16 μg/25 mL 范围内遵从比耳定律。用于工业用水和工业废水中痕量铁的分光光度测定,取得了满意的结果。     

催化动力学光度法测痕量铁(Ⅲ)的研究

研究了稀硫酸介质中 ,痕量铁 (Ⅲ )催化过氧化氢氧化甲基橙褪色的新指示反应及动力学条件 ,测定了反应速度常数和表观活化能 ,建立了催化动力学光度法测痕量铁 (Ⅲ )的新方法。其灵敏度达到 3.2× 10 - 1 1 g mL ,线性范围是 0～ 0 .3μgFe3 + 2 5mL。应用于砂糖、人发中痕量铁 (Ⅲ )的测定 ,结果满意。     

微波消解-催化动力学退色光度法测定痕量铁(Ⅲ)

将微波消解技术与铁(Ⅲ)催化过氧化氢氧化酸性格兰K的退色反应有机结合起来,并通过实验确定了测定条件.铁(Ⅲ)的检出限为8.0×10<'-9>mol/L,线性范围为1.2×10<'-8>～1.0×10-6mol/L,相关系数r=0.998 0.方法用于测定茶叶中痕量的铁(Ⅲ),结果满意.     

镁产品中痕量铁的分析方法对比研究

本文应用多种不同的测试技术对氧化镁产品中痕量铁进行了方法对照和相关问题探讨,结果表明：在配制的铁标准系列中,必须加入与试样基体含量完全一致的氧化镁,方可采用简捷快捷的火焰原子吸收准确测试氧化镁产品中的痕量铁。该结论可推广应用于其他化工产品中痕量铁的测定。     

分光光度法测定热塑性弹性体SBS中痕量铁

热塑性弹性体苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)中的痕量铁会对其材料的老化性能产生影响,准确测定材料中铁含量能够预测与铁催化老化相关信息。首先通过干法灰化法制得铁溶液,然后利用邻菲罗啉分光光度法测定热塑性弹性体SBS中的痕量铁。结果表明,吸光度与标准铁溶液的浓度呈现良好的线性关系(r=0.999),从而可以准确测出样品中的铁含量。     

5-硝基-1,10-邻菲罗啉还原合成5-氨基-1,10-邻菲罗啉的研究

综述了硝基化合物还原制备氮基化合物的主要方法。分别以氯化亚锡-盐酸、铁粉-硫酸、5％Pd／C-水合肼为催化加氢还愿体系,还原5-硝基-1,10-邻菲罗啉合成了5-氮基-1,10-邻菲罗啉。结果表明：钯炭催化剂与水合肼组成的还原体系具有较好的还原效果。     

The Determination of Solvation Numbers of Ligands,Chelates, and Complexes in Various Solvents by Differential Direct Injection Enthalpimetry,Viscosity, and Gas Chromatography Measurements

Abstract

The number of H₂O and organic solvent molecules associated with rhodo-mine B, tris-1,10-phenanthroline iron(II) chloride, and iron(III) ace-tylacetonate in seven extraction solvent systems was determined. The methods of measurement were viscosity, gas chromatography, and differential direct injection enthalpimetry.     

Analysis of forming process of nitrogen-doped carbon catalyst derived from Fe 1,10-phenanthroline compound and its oxygen reduction reaction activity

The pyrolysis behavior of iron 1,10-phenanthroline compound, the change of crystalline structure of iron in the iron 1,10-phenanthroline compound, and nitrogen chemical state of nitrogen doped carbon catalyst derived from iron 1,10-phenanthroline compound were investigated to clarify the process of improvement of oxygen reduction reaction (ORR) activity on nitrogen-doped carbon catalyst by TGA, EGA-MS, HT-XRD, XRD, and XPS technique. The ORR activity drastically improved at a synthesis temperature of 700 °C, and was the highest at a synthesis temperature of 800 °C. But the ORR activity significantly dropped at a synthesis temperature of 900 °C. This low ORR activity of NC-900 is probably due to the increase of quaternary nitrogen ratio with progression of excessive carbonization, and the quaternary nitrogen to pyridine-like nitrogen ratio might be an important factor for improvement of the ORR activity.     

Fast photometric determination of iron impurity in red lead and litharge

A method for fast photometric determination of iron impurity in red lead and litharge is suggested. The method is based on the use of reactions of complexation of iron(II) and 2,2-dipyridyl or 1,10-phenanthroline after dissolution of a specimen in a mixture of acetic acid and hydrogen peroxide and reduction of iron(III) to iron(II) by ascorbic acid.Translated from Steklo i Keramika, No. 3, pp. 28–29, March, 1995.     

Insights into the mode of action of the anti-Candida activity of 1,10-phenanthroline and its metal chelates

Metal complexes of malonie acid (metal = Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Ag(I)) were prepared and only the Ag(I) complex inhibited the growth of Candida albicans. Malonate complexes incorporating the chelating 1,10-phenanthroline (1,10-phen) ligand showed a range of activities: good (Mn(II), Cu(II), Ag(I)); moderate (Zn(II)); poor (Co(II), Ni(II)). Metal-free 1,10-phen and Ag(CH(3)CO(2)) were also highly active. The metal-free non-chelating ligands 1,7- phenanthroline and 4,7-phenanthroline were inactive and the Cu(II), Mn(II) and Zn(II) complexs of 1,7-phen displayed only marginal activity. Whereas the Cu(II) malonate/1,10-phen complex induces significant cellular oxidative stress the Zn(II) analogue does not.     

Electrode reaction of tris(1,10-phenanthroline)iron(II) complex in aqueous and non-aqueous solvents

The electrode reaction of tris(1,10-phenanthroline)iron(II) complex was studied in aqueous and non-aqueous solvents. The experimental results were compared with the diagnostic criteria derived by Nicholson and Shain. It was found that the oxidation of Fe(phen)²⁺₃ was the simple reversible reaction at low pH; however, at high pH, the reversible process was followed by the irreversible formation reaction of ferric hydroxide ion. In acetonitrile, the reversible oxidation of Fe(phen)²⁺₃ was coupled with the catalytic reduction of Fe(phen)³⁺₃ to reproduce the ferrous complex. The major cause of solvent effect on the electrode reaction could be attributed to the labile nature of ferric complex of 1,10-phenanthroline.     

Colorimetric sensor based on polymeric thin film for arsenic quantitation using colour response calibration

A simple, low-cost and portable sensor for colorimetric determination of As(III) was developed. The sensing is carried out using a microcentrifuge tube as a mini-reactor, where an Fe(III)-1,10-phenanthroline doped polyvinyl alcohol thin film is cast on the underside of the cap. Once Fe(III)-1,10-phenanthroline is reduced by arsine gas generated in situ from As(III), yielding the Fe(II)-1,10-phenanthroline complex, the red coloured product can be detected using colour analysis software. The As(III) content is then determined based upon the colour intensity of Fe(II)-1,10-phenanthroline on the film. Experimental conditions were optimised, and parameters affecting the complex formation and arsenic speciation were investigated. The method developed proved to be a selective colorimetric sensor for As(III). More significantly, the device could be directly used to detect As(III) in the field without any sample preparation requirements. The recovery for industrial wastewater and groundwater was found to be 97.5%-104.0%. Hence, the thin film-based test kit is easy to operate, portable and practical for the measurement of As(III) in the field.     

Self-oscillating microgels with Fe(phen)<Subscript>3</Subscript> catalyst induced by the BZ reaction under acid-free conditions

A novel self-oscillating microgels were prepared by copolymerization N-isopropylacrylamide (NIPAAm), organic acid and iron(II) 5-acrylamide-1,10-phenanthroline-bi (1,10-phenanthroline) (Fe(phen)₃), the catalyst for the Belousov-Zhabotinsky (BZ) reaction. The microgels were characterized by FTIR spectroscopy and scanning electron microscope (SEM). In order to illustrate the self-oscillating mechanism, the static water contact angles of the oxidized and reduced states of self-oscillating microgels were measured. In addition, the self-oscillating behaviors of the microgels were investigated in BZ system under acid-free conditions. Both the redox potential and transmittance self-oscillating were observed at room temperature.     

5-硝基苯并三唑-1-乙酸镝与1,10-邻菲啰啉配合物的合成和性质研究

采用溶液合成法,合成了标题化合物,通过元素分析、摩尔电导率、紫外光谱、红外光谱和热分析法确定配合物的组成为Dy(L)3phen.1.5H2O(HL=5-硝基苯并三唑-1-乙酸;phen=1,10-邻菲啰啉)。荧光光谱表明:镝配合物的荧光强度较强,说明配体5-硝基苯并三唑-1-乙酸和1,10-邻菲啰啉是很好的敏化剂。     

铁含量测定方法比较研究

依次以2,2’-联吡啶和1,10-菲啰啉为显色剂,研究了对应的测定铁含量的光度法的灵敏度、线性范围及常见阳离子的干扰倍数。结果显示,对干扰离子Cu2+、Ni2+及Zn2+而言,2,2’-联吡啶分光光度法的抗干扰能力较强;在回归方程线性相关系数相同的前提下,1,10-菲啰啉光度法灵敏度较高,2,2’-联吡啶分光光度法的线性范围较宽。研究结果对在一定条件下,更合理地选用测定方法,有一定的指导意义。