稀土总量的鲁米诺化学发光法测定

本法研究了离子交换分离-化学发光法测定稀土总量,其检测限为0.25ppb.线性范围为5.5×10~(-5)g/ml—2.2×10~(-10)g/ml,相对标准偏差为3.2％(浓度为1.1×10~(-9)g/ml)。同时,我们还发现Brij-35的加入,可以提高方法的灵敏度。检测限降低了7.6倍。将该法应用于矿样分析,结果令人满意。     

STUDIES ON THE CHEMILUMINESCENCE OF LUMINOL IN DIMETHYLSULFOXIDE AND DIMETHYLSULFOXIDE-WATER MIXTURES*

Abstract— The absorption, fluorescence, and chemiluminescence (CL) characteristics of luminol have been studied in basic dimethylsulfoxide (DMSO) and various basic DMSO — water mixed solvents. It has been shown that the luminol dianion can be produced quantitatively in carefully deoxygenated ‘dry’ DMSO using potassium t-butyl alcoholate (BTO) as the base. A direct correlation has been found between the intensity of CL and the concentration of luminol dianion, Indicating that the dianion is the reactive species in the chemiluminescent reaction in DMSO. Increasing concentrations of water in the mixed solvents greatly reduced the CL intensity because of the decrease in luminol dianion concentration. Solvent effects on the fluorescence of 3-aminophthalic acid samples was noted and identified. Chemiluminescent spectra of luminol were run as a function of solvent composition, and compared with fluorescence spectra in the same media. The need for correcting these spectra for comparison was noted. Stopped flow kinetic studies were run in DMSO and DMSO-water mixtures. These data can be interpreted on the basis of two second-order steps and one first-order step in the reaction. The first-order step is probably last and probably arises from decomposition of a ‘peroxy’ intermediate. The rate constant for this step is k= 1·2±0·3×10^-1 sec^-1.     

QUENCHING OF PEROXIDIZED LUMINOL CHEMILUMINESCENCE BY REDUCED PYRIDINE NUCLEOTIDES

Abstract— Reduced pyridine nucleotides were observed to cause a delay as well as a diminution of light emission from peroxidized luminol at pH 6.5. Other reductants were found to have similar effects. Neither superoxide nor hydroxyl radical scavengers quenched chemiluminescence of luminol in the presence of horseradish peroxidase and H₂O₂. A scheme in which reductants such as NADH and NADPH prevent peroxidase from oxidizing luminol to aminophthalate is proposed. Moreover, it is concluded that neither O₂⁻nor OH' play a role in the peroxidation of luminol by horseradish peroxidase.     

QUANTUM YIELDS OF THE LUMINOL CHEMILUMINESCENCE REACTION IN AQUEOUS AND APROTIC SOLVENTS*

Abstract— Quantum yields for luminol (3-aminophthalic hydrazide) chemiluminescence reactions fall into two classes depending on oxidizing conditions. In aprotic solvents the quantum yield is high and the excitation yield which allows for the fluorescence quantum yield of the product, is 0·09 and is unaffected by changes in solution temperature or polarity, or the presence of quenchers. In aqueous solution under optimum pH conditions (11–13), hydrogen peroxide oxidation results in a high chemiluminescence quantum yield with an excitation yield of 0·04 again unaffected by temperature, viscosity or quenchers. Other oxidizing conditions produce lower quantum yields probably by the introduction of competing chemical pathways. The luminol chemiluminescence light standard has been used to calibrate a spectrofluoro-meter with results in good agreement with the quantum yields of the ferrioxalate actinometer and the fluorescence of quinine sulfate and diphenylanthracene.     

KINETICS AND MECHANISM OF CATALYSIS BY FERRIHAEMS IN THE CHEMILUMINOGENIC OXIDATION OF LUMINOL BY HYDROGEN PEROXIDE

The kinetics of catalysis by deuteroferrihaem (deuterohaemin) were studied in the chemiluminogenic oxidation of luminol by hydrogen peroxide. The results imply that two distinct catalytic mechanisms operate to yield chemiluminescence from excited aminophthalate emitter in this system. The first mechanism involves initial one-electron oxidation of luminol by an oxidised derivative of deuteroferrihaem with well-established peroxidatic oxidant properties. The second mechanism involves a concerted pathway very similar to that which has been proposed [Olsson, T., L. Ewetz and A. Thore (1983), Photochem. Photobiol. 38 , 223–229] to explain protoferrihaem (haemin) catalysis in luminol oxidation. Deuteroferrihaem is a much more effective catalyst than protoferrihaem on a mole-for-mole basis and could be used with advantage in chemiluminescence analyses.     

SPECTRAL CHARACTERISTICS OF THE EXCITED STATES OF THE PRODUCT OF THE CHEMILUMINESCENCE OF LUMINOL*

Abstract— In dimethylsulfoxide the emission spectrum of luminol chemiluminescence is red-shifted by 300 cm^-1 from the photoexcited fluorescence of the product 3-aminophthalate dianion, while in aqueous solvent the two spectra are identical. The spectral properties of the product dianion have been measured in aqueous solvent and in a number of aprotic solvents, both at room temperature and at 77°K. The ground states and the excited states from which emissions are observed are characterized. Two alternatives are presented to explain the aprotic emission spectra.     

A UNIQUE ALDEHYDE CHEMILUMINESCENCE INVOLVING PEROXIDE AND COPPER I IN ACIDIC DMSO

Simple aliphatic aldehydes, when mixed with hydrogen peroxide in acidic, aprotic solvents containing copper I, chemiluminesce weakly. The reaction is very specific for copper I. Quantum yield determinations reveal a catalytic role for copper I and a 1:1 stoichiometry for aldehyde and hydrogen peroxide. Kinetics reveal that an aldehyde/peroxide adduct is the active compound and synthetic l-hydroxy octyl hydroperoxide is completely active in the reaction. Similarities in substrates. kinetics and insensitivity to extraneous substances suggest this reaction as a model for earthworm bioluminescence.     

聚乙烯等温氧化过程的化学发光光谱及动力学特性的研究

聚乙烯等温氧化过程的化学发光动力学曲线呈典型的双“S”形变化.反应一开始就出现的小的发光强度的峰值过程,与试样的氧化程度有关,接着出现的发光强度大得多的第二个和第三个峰值过程,对应于自催化氧化反应. 在480-725nm光谱范围依次观测到聚乙烯化学发光动力学曲线中的第一和第三个峰值过程,第二个峰值过程仅在330-400nm光谱范围观测到,在400-480nm光谱范围可观测到所涉及的三个峰值过程。 最后,讨论了可能的发光机制.     

银在浸出黄铜矿中的催化作用

本文研究了用Fe_2(SO_4)_3、MnO_2、FeCl_3、CuCl_2等浸出黄铜矿时Ag~ 的作用。Ag~ 在氯化物溶液中不起催化作用。但在酸性Fe_2(SO_4)_3及MnO_2溶液中可使反应速率常数提高200倍,文中导出了在Ag~ 催化作用下硫酸高铁浸出黄铜矿的动力学方程。确定了速率控制步骤是离子通过产物硫层的扩散过程,活化能为35.7kJ/mol。探讨了银催化浸出黄铜矿的反应机理。     

ACTION OF HYDROGEN PEROXIDE ON HUMAN FIBROBLAST IN CULTURE

Abstract— Human fibroblasts in culture lose the capacity of proliferating when exposed to hydrogen peroxide in the concentration range of 1 to 10 μ M . The toxicity of H₂O₂ to xeroderma pigmentosum cells (XP12RO). defective in excision repair of lesions produced by UV-irradiation, was about twice as high as to cells proficient in excision repair (VA13). This compound produces single-strand breaks in intracellular DNA but not in purified DNA. These breaks are in situ physical discontinuities rather than alkali-labile bonds, and their generation occurs at the same extent at 4°C and 37° indicating that they are not produced by an endonuclease. The results favor the hypothesis that H₂O₂ reacts in the cell producing a radical species which brings about the formation of DNA single-strand breaks. These breaks are effectively repaired by both XP12RO and VA13 fibroblasts. The possible reason for the lethality of H₂O₂ is discussed.     

含氧光敏聚合反应中表面活性剂的催化作用

本文研究了二苯酮/三乙胺/氧体系引发MMA的光聚合反应中烷基铵羧酸盐类(R₁R₂R₃R₄N⁺O^-OCR₅)离子型表面活性剂的催化作用。实验结果表明,聚合速度的大小和表面活性剂的类型,分子结构以及浓度有关。表面活性剂分子对系统中氢过氧化物光敏分解的促进,使聚合反应的量子产率提高了两倍多。     

MECHANISM OF THE REACTION BETWEEN LUMINOL AND MOLECULAR OXYGEN

Abstract— The oxidation of luminol by molecular oxygen in dimethylsulfoxide was studied by following the intensity of emitted light. The results indicate that the reaction takes place through reversible formation of an oxygen-containing intermediate. The stability constant of this compound has been determined in IDMSO: ethanol (4:1) mixed solvent. The effects of different parameters were investigated and a quantitative relationship established between the intensity of emitted light and the concentrations of the reactants.
New methods for determining (oxygen concentrations in gases and for demonstrating cold light emission are suggested.     

SYNERGISTIC LETHALITY OF PHAGE T7 BY NEAR-UV RADIATION AND HYDROGEN PEROXIDE: AN ACTION SPECTRUM

Abstract— Ozonation of valerophenone oxime o-methyl ether (4) produced a stereoisomeric mixture of crystalline dimeric valerophenone peroxides, 5a and 5b . N-n-butyl-N-methoxybenzamide (6) and N-methoxy-N-phenylvaleramide (7) along with valerophenone (1). Thermolysis of the higher melting peroxide 5a at 170–180°C, where a chemiluminescence was visible from added perylene. gave 1 and butyl benzoate (8) in addition to small amounts of the Norrish Type 11 products of 1. i.e. acetophenone (2) and cis- and trans- 2-methyl-1-phenylcyclobutanols. Biacetyl-sensitized photolysis of 5a in benzene yielded 2 in much higher yield in addition to 1, 8, and biphenyl. These results suggest that the triplet excited state of 1 is formed by the decomposition of 1 in low yield in thermolysis and in much higher yield in sensitized photolysis. although some of the Type II products may not arise from the triplet valerophenone.     

THE ROLE OF O2- IN THE CHEMILUMINESCENCE OF LUMINOL*

Abstract— The chemiluminescence of luminol in buffered aqueous solutions is inhibited by superoxide dismutase. This occurs whether the luminescence is induced by ferricyanide, persulfate, hypochlorite, or by the action of xanthine oxidase on xanthine. Since superoxide dismutase inhibits reactions which involve O₂^-, we conclude that this radical is a constant factor in the chemiluminescence of luminol in aqueous solutions. The kinetics of light production are discussed in terms of hypothetical mechanisms that fit the available data. The strong luminescence of luminol in aprotic solvents or in aqueous systems containing relatively high concentrations of H₂O₂ could not be explored in this way, because superoxide dismutase is inactive under such conditions.     

INVESTIGATION OF CATALYTIC ACTIVITY OF TRANSITION METAL SUBSTITUTED POLYOXOMETALATES FOR EPOXIDATION OF ALLYL ALCOHOL AND MALEIC ACID WITHHYDROGEN PEROXIDE

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金属离子在液相氧化中的催化作用——Ⅹ.过渡金属氯化物与简单配体原位形成的配合物在环己烯氧化反应中的催化作用

本文研究了由过渡金属氯化物(MnCl_2、FeCl_2、CoCl_2、CuCl)与2,2′-二吡啶原位形成的配合物,在环己烯氧化反应中的催化性能以及配体性质对所形成的配合物催化性能的影响.结果表明,多种过渡金属氯化物可与2,2′-二吡啶原位形成有催化活性的配合物,其催化活性与金属离子性质、形成配合物能力以及配体性质有关.     

金属离子在液相氧化中的催化作用——Ⅹ.过渡金属氯化物与简单配体原位形成的配合物在环己烯氧化反应中的催化作用

本文研究了由过渡金属氯化物(MnCl₂、FeCl₂、CoCl₂、CuCl)与2,2′-二吡啶原位形成的配合物,在环己烯氧化反应中的催化性能以及配体性质对所形成的配合物催化性能的影响.结果表明,多种过渡金属氯化物可与2,2′-二吡啶原位形成有催化活性的配合物,其催化活性与金属离子性质、形成配合物能力以及配体性质有关.     

CHEMILUMINESCENCE AND ENERGY TRANSFER OF EXCITED ACETOPHENONE

Abstract— Further evidence is found that acetophenone in its triplet-state is formed as the luminescent species in the autoxidation of ethylbenzene. Energy transfer from this ketone to the triplet-states of various acceptors results in quenching of the already weak chemilumin-escence and follows a diffusion-controlled rate as expected. The poor resemblance between the experimentally recorded spectral distribution of this light emission and the known phosphorescence spectra of the assumed emitters is discussed.     

聚氧乙烯类表面活性剂在二氯卡宾制备中的相转移催化作用

聚氧乙烯类表面活性剂可作为制备二氯卡宾时的相转移催化剂,其效能与分子中氧乙烯(EO)单位的数目有关。     

THE QUANTUM YIELD OF THE CHEMILUMINESCENCE OF DIMETHYLBIACRIDYLIUM NITRATE AND THE MECHANISM OF ITS ENZYMICALLY INDUCED CHEMILUMINESCENCE*

Abstract— Quantum yields for dimethylbiacridylium ion chemiluminescence based on the amount of methyl acridone formed by treatment with either H₂O₂ or with xanthine oxidasehypoxanthine in 0.01 M Na₂CO₃ at pH 10.4 and at 25°C were found to lie between 0.011 and 0.020 with an average of about 0.016.In mixed solvents containing pyridine and water or alcohol and water the emission spectrum of chemiluminescence of dimethylbiacridylium ions as well as those of diniethylbiacridene and its oxide were found to be identical with or very similar to the fluorescence of methyl acridone in the same solvent.A mechanism involving two successive two equivalent reductions of the diniethylbiacridylium ion to dimethylbiacridan followed by a radical attack and auto-oxidation leading to a compound which can undergo a reverse aldol type reaction to yield one (or two) molecule of methylacridone and one of a somewhat more reduced form is suggested.The kinetic equation relating maximum intensity of chemiluminescence to dimethylbiacridylium ion, hypoxanthine, xanthine oxidase, H⁺ and O₂ concentrations was derived from the scheme suggested and found to fit satisfactorily the data obtained from a series of experiments in which the quantum yield was also obtained.