荧光猝灭法测定人发中微量锰

异丙肾上腺素在pH9.91的伯瑞坦 罗比森缓冲溶液中被MnO-4氧化,导致其荧光强度显著减弱。最大激发及发射波长为278nm和616nm,MnO-4浓度在0.01～0.64mg·L-1范围内,荧光强度与浓度呈良好线性关系。将其用于人发中微量锰的测定,得到满意的结果。     

锰（Ⅱ）—邻菲口罗啉配合物极谱吸附波及其应用

在ｐＨ９．５ＮＨ３ＮＨ４Ｃｌ缓冲溶液中，Ｍｎ（Ⅱ）与邻菲口罗啉形成的配合物在－１．３６Ｖ（ｖｓ．ＳＣＥ）处产生一灵敏的吸附波，一阶导数峰电流与Ｍｎ（Ⅱ）浓度在５×１０－８５×１０－６ｍｏｌ／Ｌ范围内呈线性关系，检出限为２×１０－８ｍｏｌ／Ｌ对极谱性质及反应机理进行了研究，用该法测定了大豆和茶叶中的微量锰，结果满意     

On-line enrichment system for manganese determination in water samples using FAAS

An on-line preconcentration procedure for the determination of manganese using flow-injection approach with flame atomic absorption spectrometry as a detection method is described. The proposed method is based on the complexation between Mn(II) and 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP). Two approaches were investigated for enrichment of manganese; the formation of Mn-TCPP complex in a solution followed by its retention on a sorbent and the sorption of manganese ions onto the TCPP-modified resin. The best results was obtained for the first approach when 10⁻⁵ M reagent was on-line mixed with an aqueous sample solution and passed through the microcolumn packed with anion-exchange resin Amberlite IRA-904 for 5 min. The sorbed complexes were then eluted with 0.5 ml of 2 M HNO₃. A good precision (2.2-3.1% R.S.D. for 50 μg l⁻¹ manganese) and the enrichment factor of 30 were obtained with the detection limit of 12 μg l⁻¹ for 5 min loading time. The interference of anions and cations has been studied to optimize the conditions and the method was applied for determination of manganese in natural water samples. The results obtained by FI-FAAS and ETAAS (as a reference method) were not statistically different for a significance level of 0.05.     

Electropolymerized Pyrrole‐Substituted Manganese Phthalocyanine Films for the Electroassisted Biomimetic Catalytic Reduction of Molecular Oxygen

We report for the first time on the electroassisted biomimetic activation of molecular oxygen by a newly prepared electropolymerized polypyrrole‐manganese phthalocyanine film. The prepared films and their intervention in the electroassisted catalytic reduction of molecular oxygen were analyzed by cyclic voltammetry and UV‐visible spectrophotometry on optically transparent electrodes. The obtained results demonstrate the probable existence of the key‐steps responsible for the suggested formation of the highly reactive manganese oxo intermediate.     

Scanning electron microscopic studies on different habits of gel grown doped manganese carbonate crystals

The effect of impurities on the growth of manganese carbonate crystals has been studied. Stereophotogrammetric analysis showed that all crystal faces have the same Miller indices and the peanut-shaped forms are twins with twin axis 0001.     

Use of a Tensammetric Wave for the End-Point Detection in Chelatometry

Abstract

A new method for the end-point detection in complexometric titration using a tensammetric wave of organic reagents such as oxine and alizarin complexone (ALC) was studied. The tensammetric wave of these reagents disappears by their chelate formation and reappears by the liberation of free indicator during the exchange reaction between indicator chelate and EDTA. This mechanism is utilized for the end-point detection in complexometric titration of metals. Since the sensitivity of tensammetric wave is extremely high, very sharp end-point can be obtained for the titration of metals even in the concentration of 10^?5M.     

Co-crystallizing coordination compounds

Crystallization of an equimolar mixture of 1,10-dimethylphenanthroline (DMP) and manganese(II) chloride from N,N-dimethylformamide (DMF) has been studied. Rather than a useful route to a well-defined product, it was found that identical solutions could deposit crystals of three different compounds. The most common outcome was the formation of crystals of [MnCl₂(dmp)(dmf)], 1, or co-crystallization of [MnCl₂(dmp)(dmf)] and [{MnCl₂(dmp)}₂]. The co-crystals, 2, were always found to dissolve as crystals of 1 started to grow. Crystals of a third compound, [MnCl₂(dmp)₂], 3, were also isolated once.     

Syntheses,characterizations and bioactivities on HeLa cells and KB cells of two dinuclear manganese complexes with carboxylate bridges

To explore anti-tumor activities of manganese complexes, two complexes have been synthesized and characterized. Complex 1 is bridged by 1,10-phenanthroline and 2,4-biphenyl dicarboxylate. The two complexes have strong fluorescent emission and interact with DNA in an intercalative mode. The complexes also exhibit significant cytotoxic specificity and cancer cell inhibition.     

ICP－AES法测定钨合金中镍、钴、铁、锰时酸度的影响

本文研究了用电感耦合等离子体发射光谱技术测定钨合金中镍、钴、铁、锰含量的方法及酸度对测量结果的影响。用氢氟酸及硝酸处理试样，并加入适量盐酸。实验研究了测量值随氯离子浓度增大而下降的变化曲线，找出了测量不同元素的最佳测定条件，测量结果同标准值比较，误差较小。     

Ultrasound-assisted facile one-pot synthesis of ternary MWCNT/MnO2/rGO nanocomposite for high performance supercapacitors with commercial-level mass loadings

Commercial application of supercapacitors (SCs) requires high mass loading electrodes simultaneously with high energy density and long cycle life. Herein, we have reported a ternary multi-walled carbon nanotube (MWCNT)/MnO₂/reduced graphene oxide (rGO) nanocomposite for SCs with commercial-level mass loadings. The ternary nanocomposite was synthesized using a facile ultrasound-assisted one-pot method. The symmetric SC fabricated with ternary MWCNT/MnO₂/rGO nanocomposite demonstrated marked enhancement in capacitive performance as compared to those with binary nanocomposites (MnO₂/rGO and MnO₂/MWCNT). The synergistic effect from simultaneous growth of MnO₂ on the graphene and MWCNTs under ultrasonic irradiation resulted in the formation of a porous ternary structure with efficient ion diffusion channels and high electrochemically active surface area. The symmetric SC with commercial-level mass loading electrodes (∼12 mg cm⁻²) offered a high specific capacitance (314.6 F g⁻¹) and energy density (21.1 W h kg⁻¹ at 150 W kg⁻¹) at a wide operating voltage of 1.5 V. Moreover, the SC exhibits no loss of capacitance after 5000 charge−discharge cycles showcasing excellent cycle life.