免疫分析法进展

本文首先从试剂分析的观点对免及分析的原理进行了论.述,对抗体作为分析试剂进行了评价并且总结了标记免投分析的三种方式和四个环节;其次,对免疫分析的现状作了综述,并评述了当代免反分析的五个热点:基因工程抗体,生物素一亲合素多重标记体系,时间分辨荧光免疫分析,多组分免疫分析和自动化免疫分析;最后,对免疫分析的发展趋势作了讨论。     

分子团簇的量子化学研究

采用Hartree-Fock方法、密度泛函(DFT)方法(BLYP、B3LYP)和MP2方法对Se4分子团簇的各种可能构型进行了结构优化和频率分析, 结果表明有5种构型是势能面上的稳定驻点, 同时对上述4种量子化学方法计算结果的差异进行了分析。并对这5种构型的结构稳定性、几何构型、前线分子轨道、Mulliken布局分析和偶极矩进行了分析, 根据分析结果对Se4分子的某些物理和化学性质进行了预测。     

食品中农药残留分析的样品前处理技术进展*

本文综述了近年来食品中农药残留分析的样品前处理技术,重点对超临界流体萃取法在食品农药残留分析中的应用及其联用技术进行了评述;同时对固相微萃取、微波辅助萃取和凝胶渗透色谱法进行了总结。对食物中农药残留分析技术的发展方向进行了讨论。     

毛细管电泳技术在氨基酸分析中的研究进展

对毛细管电泳技术在氨基酸分析中的研究进展进行了综述,分析了直接法和衍生法对氨基酸进行分析的优缺点,详细叙述了毛细管电泳中的紫外、激光诱导荧光、电化学及质谱等检测方法在氨基酸分析中的应用,并重点总结了毛细管电泳在手性氨基酸分离中的应用.     

活性炭表面基团的定性和定量分析

利用过硫酸铵对石油焦基活性炭进行了氧化处理, 并使用元素分析、 傅里叶变换红外光谱(FTIR)、 带质谱检测的程序升温脱附(TPD-MS)、 X射线光电子能谱(XPS)和X射线吸收近边结构(XANES)等方法对样品进行了分析和表征, 并对不同表征方法所得结果进行了对比分析. 结果表明, 元素分析所得结果与TPD-MS分析结果较吻合, XPS和XANES分析所得含氧量结果偏小.     

NICS判据在五元杂环化合物芳香性教学中的应用

运用NICS判据对五元杂环化合物的芳香性进行了分析,并对引入到有机化学教学中进行了探讨,可通过简单的数值来分析不同杂环化合物的芳香性。     

GD-MS法和ICP-MS法测定高纯铌中痕量元素

采用辉光放电质谱法(GD-MS)对高纯铌中Ta,Mo,W等痕量杂质元素进行了测试,并对GD-MS工作参数进行了优化,部分元素与采用电感耦合等离子体质谱法(ICP-MS)定量分析的结果进行比较,对某些元素含量差别较大的原因进行了分析,论述了Element GD辉光放电质谱仪的特点及其在痕量杂质分析上的优势。     

气相色谱在食品检测方面的应用及进展

对近年来气相色谱技术在食品检测方面的应用进行综述,主要包括农药残留分析,食品添加剂分析,兽药残留分析以及食品包装材料中挥发物分析,并对未来的应用进行了展望。     

"上火"的机制及奶粉上火的探讨

对“上火”的定义、分类,机理及奶粉的定义、品种进行了分析.通过对清火物质的分析,提出了清火奶粉的清火机制,并对“喝了不上火”的系列奶粉进行了生产工艺及营养学设计的探讨.     

Fe(Ⅲ)、Co(Ⅱ)、Ni(Ⅱ)、Cu(Ⅱ)和Zn(Ⅱ)含硫Schiff碱配合物的合成

合成了5种含硫Schiff碱,8种相应的金属配合物。并对合成的配体和配合物进行了元素分析,红外光谱分析。对有代表性的化合物还进行了¹HNMR和质谱分析。确定了可能的分子结构式。     

多壁碳纳米管表面过氧化苯甲酰印迹复合材料的制备及固相萃取应用

以过氧化苯甲酰(BOP)为模板分子,甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,偶氮二异丁腈(AIBN)为引发剂,采用热聚合法在多壁碳纳米管(MWNTs)表面制备印迹聚合物(MWNTs-MIPs)。采用红外和热重分析等技术对聚合物结构进行表征。采用液相色谱考察该分子印迹聚合物对过氧化苯甲酰的吸附特性。结果表明该印迹聚合物对过氧化苯甲酰表现出特异性吸附,该印迹聚合物对模板分子存在一种结合位点,其最大表观结合量为56.20 µmol/g。该印迹聚合物成功应用于固相萃取富集面粉中微量过氧化苯甲酰,浓度富集因子为526。     

The Role of a Metallocene Additive in Radically Initiated Polymerization when Solving Direct and Inverse Kinetic Problems

Polymerization of methyl methacrylate, initiated by benzoyl peroxide in the presence of titanocene dichloride, is considered from the point of view of formal kinetics. Based on the kinetic scheme of the process (which includes the reactions of classical radical polymerization, the reaction of benzoyl peroxide with titanocene dichloride, the reactions of the controlled radical polymerization of organometallic mediated radical polymerization (OMRP) and atom transfer radical polymerization (ATRP), the reaction of the formation of a coordinating active site and the coordinating chain propagation on a mathematical model of the kinetics of the process is created. This model also makes it possible to calculate the molecular-mass characteristics of poly(methyl methacrylate). As a result of the solution of the inverse kinetic problem at a temperature of 343 K, the values of the reaction rate constants of the kinetic scheme are found under which the discrepancy between the calculated models and experimental data is minimal. Using the developed model of the kinetics of the process, a numerical experiment is performed (i.e., a direct kinetic problem is solved). This problem revealed the following regularities of the process. (1) An increase in the initial concentration of titanocene dichloride at a constant initial concentration of benzoyl peroxide leads to an increase in the rate of consumption of benzoyl peroxide but not to an increase in the initial rate of the process compared to classical radical polymerization. (2) With an increase in the initial concentration of titanocene dichloride, the lifetime of the macroradicals at the initial stage of the process is reduced, and hence the molecular weight of the resulting polymethyl methacrylate is less than that of the polymethyl methacrylate obtained in the absence of titanocene dichloride, and it will increase during the process of approaching the final values. (3) During the polymerization of methyl methacrylate, initiated by benzoyl peroxide in the presence of titanocene dichloride, a smoothing gel effect (as in the case of the polymerization of methyl methacrylate initiated by benzoyl peroxide in the presence of ferrocene) does not occur since titanocene dichloride forms stable complexes with methyl methacrylate and, consequently, it participates in reactions consuming macroradicals to a lesser degree than ferrocene.     

Comparison of isothermal and non-isothermal chemiluminescence and differential scanning calorimetry experiments with benzoyl peroxide

Difference in the kinetics of chemiluminescence (CL) and differential scanning calorimetry records for decomposition of originally solid benzoyl peroxide continuing as a melt reaction was outlined. While the main portion of heat measured by DSC is released in the spontaneous decomposition of benzoyl peroxide starting as a homolytic scission of peroxidic bonds, the CL light emission in oxygen comes presumably from the subsequent disproportionation reaction of polyphenyl peroxyl radicals and monitors the induced decomposition of peroxide. Thermogravimetry revealed that oxygen remains partially bound to the products of benzoyl peroxide decomposition.     

Catalytic and inhibiting effects of ferrocene on the bulk radical–coordination polymerization of methyl methacrylate from the standpoint of formal kinetics

The kinetic curves and rates of bulk radical–coordination polymerization of methyl methacrylate initiated by the benzoyl peroxide–ferrocene system at 293–373 K, initial benzoyl peroxide concentrations of 10^–4–10^–1 mol/L, and a constant initial ferrocene concentration of 10^–3 mol/L have been calculated using a mathematical model in which the process is considered from the standpoint of formal kinetics. The calculations have demonstrated that, at low methyl methacrylate conversions, ferrocene catalyzes the process at any benzoyl peroxide concentration; at medium and high methyl methacrylate conversions, deficient amounts of ferrocene with respect to benzoyl catalyze the process as well, while excess ferrocene inhibits the process. The observed effect is explained by the specific ferrocene–benzoyl peroxide interaction, which, depending on the ferrocene: benzoyl peroxide ratio, either increases or decreases the concentration of radicals in the reaction mass.     

Chemiluminescence method for determination of benzoyl peroxide in solution

The chemiluminescence reaction of benzoyl peroxide with triethylamine is used to quantify benzoyl peroxide. The method is rapid with a detection limit for benzoyl peroxide in chloroform of 0.07 μg ml^?1 and a relative standard deviation of 4% at 1 μg ml^?1. The technique is applied to the determination of benzoyl peroxide in pharmaceutical preparations.     

过氧化苯甲酰的测定与应用研究

本文提出了一种以丙酮为溶剂,柠檬酸为催化剂和掩蔽剂的间接磺量法以测定过氧化苯甲酰。该方法简便易行,重现性好,准确度高,测定结果令人满意。     

Reaction of Acenaphthylene with the Benzoyloxy Radical

Acenaphthylene (ACN) has been polymerized at 60° C using benzoyl peroxide labeled with carbon-14 and tritium as the Lnitiator. End-group analyses show a very high proportion of benzoate groups among the incorporated initiator fragments. It is deduced that ACN is much more reactive than most other monomers toward the benzoyloxy radical. There is evidence that transfer to benzoyl peroxide is significant during the polymerization of ACN.     

60Co-initiated polymerization of styrene,vinyl acetate,and their mixtures in the presence of a radical initiator

Styrene and vinyl acetate have been polymerized by γ-radiation in the presence of α,α′-azobisisobutyronitrile or benzoyl peroxide. Benzoyl peroxide does not affect the vinyl acetate polymerization, but the rate of polymerization is greatly increased by the action of the initiator in the case of the following systems: styrene–α,α′-azobisisobutyronitrile, styrene–benzoyl peroxide, and vinyl acetate–α,α′-azobisisobutyronitrile. For these three systems, the experimental results are in good agreement with a kinetic scheme obtained by assuming an energy transfer process from monomer excited molecules to the initiator; this process does not occur in the first system, and the initiation rate is determined only by the vinyl acetate concentration. In the case of the polymerization of mixtures of the two monomers, the action of α,α′-azobisisobutyronitrile and that of benzoyl peroxide are practically the same; that is, the shape of the polymerization curve may be understood on the basis of an energy transfer from styrene excited molecules to the initiator.     

柱后衍生-高效液相色谱-荧光检测法测定面粉中的过氧化苯甲酰

利用过氧化苯甲酰能够在氯化血红素的催化下将底物对羟基苯乙酸氧化成具有荧光的二聚体的性质,建立了柱后衍生-高效液相色谱-荧光检测法测定面粉中过氧化苯甲酰的方法。优化了色谱分离条件和柱后衍生条件,结果表明:催化剂氯化血红素的浓度为8μmol/L,底物对羟基苯乙酸的浓度为80μmol/L,衍生化试剂的pH 10.5,衍生温度为35℃时衍生效率最高。在优化条件下,过氧化苯甲酰的线性范围为0.5～100 mg/L;样品的检出限为1 mg/kg,样品的加标回收率为98.5%～99.5%。本方法与现有的高效液相色谱法相比,检测面粉中过氧化苯甲酰具有抗干扰能力强,灵敏度高。     

A novel capillary microliter droplet sample injection-chemiluminescence detector and its application to the determination of benzoyl peroxide in wheat flour

A novel capillary microliter order droplet injection-chemiluminescence (CL) system is proposed. In this system, the liquid sample microdrops, automatically formed at the end of a capillary tip by the effect of the gravity and the gas pressure, repeatedly drop into the miniature reaction cell and reacts with CL reagent to generate CL signal. The phenomena of sample zone dilution and spreading are eliminated as the capillary is used as the sample channel and gas pressure is used as driving force without the liquid carrier stream. Therefore, a high sensitivity is obtained. To evaluate the applicability of the proposed method, a determination of benzoyl peroxide (BP) is examined. The system shows that the benzoyl peroxide is detected linearly in the concentration range from 5×10⁻¹⁰ to 1×10⁻⁶ g ml⁻¹. The detection limit (signal-to-noise ratio=3) is 1.4×10⁻¹⁰ g ml⁻¹ for benzoyl peroxide (mass concentration is 1.1 pg, i.e., 4.5 fmol), which is the best result reported so far. The relative standard deviation (n=11) is 1.5% for 2.0×10⁻⁸ g ml⁻¹ BP. The proposed detector for the detection of benzoyl peroxide offers the advantages of sensitivity, simplicity, rapidity, automation and miniaturization. The proposed method has been applied satisfactorily to the determination of benzoyl peroxide in wheat flour.