在线氧含量分析中的自动反吹

为解决在线氧含量分析测试仪表常被聚合物堵塞的问题，提出了自动反吹的时序分配和实施控制方案，从而为安全生产提供了保障。     

检测实验室如何开展管理评审工作

详细论述了管理评审的基本概念、如何开展管理评审工作以及中国实验室国家认可委员会的有关政策。     

高温氧化-化学发光检测法测定水中总氮

采用高温氧化-化学发光检测法（high temperature oxidation ＆ chemiluminescence, HTO-CL）进行水质总氮（TN）的在线测定。总氮浓度（CN）与化学发光的强度（IN）呈良好的线性关系，线性区间为0．05～100mg／L。对真实水样采用本方法进行测定，其结果与国标方法相符，回收率在90％～110％之间。以本方法为工作原理的TN-2000型总氮测定仪可用于地表水质及污水的在线监测。     

多晶顺磁共振谱的拟合

对电子自旋1/2≤S<3.5,核自旋1/2≤I<4.5和配体少于10个的顺磁体系的多晶EPR谱的拟合进行研究。在VAX-11/785计算机上用FORTRAN语言建立EPR谱模拟程序包,计算了多个例子,获得较为满意的结果。     

透射电镜薄样品倾转过程中的附加旋转及其计算

模拟透射电镜双倾台进行样品位向调整过程,推导出反映样品倾转前后其合成倾转轴(即共有菊池线对的法线)方向变化规律的计算公式,称为附加旋转角计算公式。指出,实现样品位向调整的双倾操作,等效于样品绕其合成倾转轴的倾转及该倾转轴绕Z轴(平行入射束方向)的旋转之和。利用双倾台对薄膜样品进行的系列倾转实验表明,由附加旋转角公式计算的附加旋转角和实测值相一致。还根据双倾操作过程导出了合成倾转角的计算公式,它可用于判断样品位向调整的准确度。     

轻稀土硝酸盐与邻菲罗啉(Phen)高配比混配配合物的合成和表征

本文采用水-有机溶剂合成了三个稀土硝酸盐与邻菲罗啉的混配配合物,通过元素分析、红外、差示扫描和热重等分析测试手段,确证了配合物的组成为Ln(Phcn)_4(NO_3)_3·3H_2O,并研究了它们的性质。     

Chiral separation of the four stereoisomers of a novel antianginal agent using a dual cyclodextrin system in capillary electrophoresis

Reported here is an analytical method enabling the stereochemical resolution of a new antianginal compound possessing two stereogenic centers, leading to four stereoisomers. Only one of these isomers is currently under development as a novel antianginal agent and consequently, the other three isomers are considered as unwanted chiral impurities. Therefore, an enantioselective method is required in order to check its enantiomeric purity. This paper presents a method exploiting the high efficiency of capillary electrophoresis and the complexing properties of cyclodextrins to achieve the separation of the four stereoisomers of this weakly basic compound (pKa = 7.4). For this purpose, the combination of a neutral cyclodextrin, hydroxypropyl-gamma-cyclodextrin (HP-gamma-CD), and an anionic cyclodextrin, carboxymethyl-beta-cyclodextrin (CM-beta-CD), was added to the separation buffer running in an uncoated silica capillary. After selection of the suitable cyclodextrin system, satisfactorily separation conditions were as follows: 30 mM phosphate buffer (pH 6.4) containing 10 mM of HP-gamma-CD and 10 mM of CM-beta-CD, running voltage +30 kV. The resulting run time and resolutions were respectively about 17 min and between 1.95 and 2.84. Linearity curves (0.993 < r2 < 0.998) are also shown.     

Near-crater discoloration of white lead in wall paintings during laser induced breakdown spectroscopy analysis

During Laser-Induced Breakdown Spectroscopy (LIBS) analysis of white lead pigment (basic lead carbonate, 2PbCO₃·Pb(OH)₂), used in wall paintings of historical interest, a yellow–brown discoloration has been observed around the crater. This phenomenon faded after a few days exposure under ambient atmosphere. It was established that the mechanism of this discoloration consists in lead oxides (PbO) formation. It was verified by further experiments under argon atmosphere that recombination of lead with oxygen in the plasma plume produces the oxides, which settle around the crater and induce this discoloration. The impact of discoloration on the artwork's aesthetic aspect and the role of atmosphere on discoloration attenuation are discussed. The mechanism is studied on three other pigments (malachite, Prussian blue and ultramarine blue) and threshold for discoloration occurrence is estimated.     

Dynamically coating the capillary with 1-alkyl-3-methylimidazolium-based ionic liquids for separation of basic proteins by capillary electrophoresis

Ionic substances with melting points close to room temperature are referred to as ionic liquids. Because ionic liquids are environmentally benign and are good solvents for a wide range of both organic and inorganic materials, interest for their potential uses in different chemical processes is increasing. In this paper, a capillary electrophoretic method for the analysis of basic proteins including lysozyme, cytochrome c, trypsinoge, and α-chymotyypsinogen A is reported. The method, in which 1-alkyl-3-methylimidazolium-based ionic liquids are used as the running electrolytes, leads to a surface charge reversal on the capillary wall. The effects of the alkyl group, imidazolium counterion, and the concentration of the ionic liquids were discussed. The optimum buffer system was a 90 mM 1-ethyl-3-methylimidazolium tetrafluoroborate (1E-3MI-TFB) solution. The applied voltage was −15 kV and detection was performed by monitoring absorbance at 240 nm. Baseline separation, high efficiencies, and symmetrical peaks of four proteins were obtained. The R.S.D. values of migration times and peak areas were <0.68 and <3.0%, respectively. The separation mechanism seems to involve association between the imidazolium cations and the proteins.     

实验室废液的回收及效果评价——以“铬废液回收及评价”为例

This paper introduces an experiment about waste liquid recovery and effect evaluation in laboratory. Through this experiment, the basic operations of crystal preparation, chemical analysis and instrumental analysis are further consolidated. At the same time, it allows students to experience a series of possible problems of condition selection and control in the process of waste liquid treatment. We hope to improve the students' ability to analyze and solve problems, enhance their interest in learning, and strengthen their humanistic education.