一种高选择性固相萃取剂的合成及对汞(Ⅱ)的分离富集特性

制备了二甲酚橙键合硅胶(SGMXO)固相萃取剂,研究了它对常见重金属离子的分离富集行为,发现对水中痕量Hg2 有较好的选择性分离富集效果。系统考察了溶液的pH、过柱流速、洗脱液浓度及流速、柱始漏量及不同金属离子对Hg2 的定量回收的影响。在pH=1.0条件下,可在Cd2 、Pb2 、Cu2 、Mn2 等多种性质相近的金属离子存在时,对Hg2 进行选择性分离富集。所合成的固相萃取剂在使用50次后仍能重复出实验现象。该法用于对实际样品中Hg2 的分离富集,回收率在99%以上。     

苯甲酰偶氮间苯二酚氨丙基键合硅胶的制备及其富集、分离痕量元素的研究

本文介绍了苯甲酰偶氮间苯二酚氨丙基键合硅胶(BARA·SG)的合成方法,研究了BARA·SG的性质及其对痕量元素的富集和分离。结果表明:BARA·SG在6mol/L HCl～pH9.0的溶液中稳定;对Cu(Ⅱ)的最大吸附量为26.3μmol/g。在pn5.0时,经BARA·SG柱预富集处理后,可测定水样中ng/g级的Cu(Ⅱ);调节溶液的pH为2.7,痕量UO_2(Ⅱ)、Pd(Ⅱ)、Pt(Ⅳ)可与常见过渡金属离子、稀土金属离子直接柱上分离;采用分步洗脱方法,可将UO_2(Ⅱ)与Pd(Ⅱ)、UO_2(Ⅱ)与Pt(Ⅳ)分离。色层柱可重复使用多次,用普通分光光度法测定痕量元素的下限可达ng/g级。     

一种高选择性汞(Ⅱ) 吸附剂的制备和应用

利用两步反应法制备了溴联苯三酚红功能性硅胶(BPRSG),并通过静态平衡方法研究了该功能性硅胶对多种性质相近的金属离子的选择性吸附性能,考察了溶液pH值和搅拌时间对Hg?吸附率的影响。结果表明,在pH=7.0时,该固相萃取剂对Hg(Ⅱ)有特异的选择性吸附,可以实现与Pb(Ⅱ),Co(Ⅱ),Mn(Ⅱ),Zn(Ⅱ),Cu(Ⅱ),Cd(Ⅱ),Ni(Ⅱ)等金属离子的选择性分离,对Hg?的吸附平衡时间为30 min;最大吸附容量为4.80 mg/g。将该吸附剂制成微型固相萃取柱,用动态平衡法研究了柱流速、洗脱剂种类、洗脱速度和各种干扰离子对分离富集Hg(Ⅱ)的影响。在优化条件下,微柱对Hg?的最低富集浓度为10μg/L,富集倍率为170倍,柱容量为0.65 mg/g。20种常见离子不干扰Hg?的吸附,用1.0 mol/L醋酸即可洗脱Hg(Ⅱ),柱子可重复使用。将微柱用于环境水样中Hg?的固相萃取,回收率在95.5%～98.0%之间。     

苯甲酰双偶氮胂Ⅰ氨丙基键合硅胶的制备、性质及其富集、分离痕量Pd(Ⅱ)的研究

本文介绍苯甲酰双偶氮肿Ⅰ氨丙基键合硅胶(BAAI·SG)的合成方法,研究了BAAI·SG的性质及其富集、分离痕量Pd(Ⅱ)的工作。研究结果表明:BAAI·SG在6mol/LHCl至pH9.O溶液中都是稳定的;Pd(Ⅱ)与BAAI·SG的吸附平衡20min即可达到,最大吸附率为90％;BAAI·SG、SG对Pd(Ⅱ)的最大吸附容量分别为52.7μmol/g,23.5μmol/g;经BAAI·SG柱预富集处理后,可测定人工水样中ppb级的Pd(Ⅱ);色层柱可重复使用多次;用分光光度法测定痕量Pd(Ⅱ)的下限可达ppb级。     

酸性铬蓝K键合硅胶的制备,性质及其富集,分离痕量元素的研究

酸性铬蓝Ｋ键合硅胶的制备、性质及其富集、分离痕量元素的研究张玉果，刘锋，李克安，李冬梅，吴燕昇，童沈阳（北京大学化学与分子工程学院，北京，１００８７１）关键词ＡＣＢＫ·ＳＧ，预富集与分离，分光光度法，Ｐｄ（Ⅱ），Ｐｔ（Ⅳ）本文在制得键合型改性硅胶的基...     

氧化锆微球担体-8-羟基喹啉鳌合固定相的合成及其在痕量金属分析中的应用

以氧化锆微球为担体,通过mannich反应得到在氧化锆微球上键合8-羟基喹啉的痕量金属富集分离固定相,并对该固定相的键合金属离子能力进行了研究。以合成的氧化锆微球键合8-羟基喹啉金属鳌合固定相用作微柱流动注射(FIA)在线分离、富集和电感耦合等离子体质谱(ICP-MS)分析流程中的固定相,对大洋海水中的痕量铅和镉进行了在线分析,得到了较满意的结果。     

二苯卡巴腙键合硅胶的制备及对废水中重金属的分离与富集

研究了二苯卡巴腙化学键合硅胶和物理吸附硅胶的制备方法以及2种修饰硅胶的性质。结果表明：二苯卡巴腙化学键合硅胶的稳定性、使用寿命及最大富集量均高于物理吸附硅胶。在一定条件下,多种金属离子共存时,化学键合硅胶对痕量Hg^2＋,Cd^2＋,Zn^2＋和Cu^2＋有较好的选择性富集效果。考察了最佳富集条件,在适宜pH时,4种金属离子可同时富集;也可分步富集,选用不同洗脱剂可分步洗脱,从而达到不同金属离子与其他离子的分离。     

2-巯基苯并噻唑直接键合硅胶的制备及其对Cu（Ⅱ）的吸附性能研究

采用一种简单有效的方法合成了2-巯基苯并噻唑(MBT)直接键合硅胶.将键合硅胶用于水中Cu(Ⅱ)的吸附,考查了溶液pH值的影响.结果表明当pH为6时,键合硅胶的吸附量最大.通过分批实验,研究了278K、293K和308K 3个温度条件下的吸附平衡.应用Langmuir和Freundlich两个双参数等温线模型进行拟合,MATLAB软件的误差分析表明,Freundlich模型与实验数据更加吻合.计算得到吸附过程的热力学参数△G°、△H°和△S°的值分别为-21.90kJ/mol(293K)、14.57kJ/mol和124.61J/(mol·K).结果表明,键合硅胶对Cu(Ⅱ)的吸附是一个自发进行的吸热过程.     

1,8-二羟基萘-3,6-二磺酸键合硅胶的制备、性质及其富集分离痕量元素的研究

本文介绍了1，8－二羟基萘－3，6－二碳酸键合硅胶（HNSA·SG）的合成方法，研究了HNSA·SG的性质及其对痕量元素的富集和分离行为。结果表明：HNSA·SG能在6mol／LHCl～pH8．0的溶液及常见有机溶剂中稳定存在；对Pd（Ⅱ）和Cu（Ⅱ）的最大吸附量分别为353μmol／g和197μmol／g；pH2．0时，可用HNSA·SG柱将痕量Pd（Ⅱ）与常见过渡金属离子分离；pH6．0时，HNSA·SG柱可将痕量Cu（Ⅱ）与性质相近的Pb（Ⅱ）、Cd（Ⅱ）、Mn（Ⅱ）、Co（Ⅱ）、Ni（Ⅱ）等金属离子分离。经柱富集后，可用分光光度法测定水样中痕量Cu（Ⅱ），测定下限可达ng／g级。     

硅胶G基纳米钛酸锶钡吸附富集-火焰原子吸收法对水中Pb~(2+)的测定

采用溶胶-凝胶法制备了硅胶G基纳米钛酸锶钡,并且用X射线衍射(XRD)、扫描电镜(SEM)和傅立叶变换红外光谱(FTIR)进行了表征.系统地研究了该物质对水中铅的吸附性能.提出了硅胶G负载纳米钛酸锶钡分离富集,FAAS法测定水中痕量铅的新方法.结果表明,纳米钛酸锶钡能够负载于硅胶G表面,制成蚕茧状颗粒吸附材料.在pH值为4～6时,该吸附剂对水中的铅离子具有很强的吸附能力,静态吸附容量达到86.28m/g.吸附在硅胶G负载纳米钛酸锶钡上的铅离子可用1mol/L的硝酸完全洗脱下来,经硅胶G负载纳米钛酸锶钡富集10倍后,方法检出限为7.4μg/L.用于河水和自来水中痕量铅的测定,结果满意.     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

物质分配系数的测定实验改进

实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.