逐级稀释法快速判断电感耦合等离子体质谱法测定不锈钢时的基体效应

正电感耦合等离子体质谱法(ICP-MS)是近年来发展较快的无机痕量元素分析技术,具有检出限低、精密度高、动态线性范围宽、可多元素同时测定等优点,在冶金行业中用于高纯金属材料中痕量及超痕量元素的测定。但ICP-MS分析中存在的干扰严重影响测定结果的准确性。ICP-MS分析中的干扰可分为质谱干扰和非质谱干扰(又称基体效应)两类,     

高分辨电感耦合等离子体质谱法测定镍基单晶高温合金中36种痕量元素

基于高分辨电感耦合等离子体质谱法(HR-ICP-MS)的质谱干扰消除技术,对镍基单晶高温合金中36种痕量元素检测的质谱条件、基体干扰、质谱干扰与同位素选择进行了研究。取样品0.100 0 g,用体积比为3∶1的盐酸-硝酸混合酸10 mL、氢氟酸1 mL溶解,用水定容至250 mL。通过复杂基体质谱干扰计算判定、共存元素干扰消除,确定了待测元素的同位素和分辨模式,将镍基单晶高温合金中痕量元素准确测定的元素种类确定为36种。采用标准加入法进行定量分析,36种痕量元素的检出限(3s)为0.004～6.000μg·L^-1。方法用于分析国际标准物质,得到的测定值与认定值基本一致。方法用于镍基单晶高温合金样品分析,36种痕量元素的检出量为0.000 001 0%～0.018%。     

高流速辉光放电质谱法测定镍基单晶高温合金中43种痕量元素北大核心CSCD

基于高流速辉光放电质谱法(GDMS)的质谱干扰消除技术,对镍基单晶高温合金中43种痕量元素的质谱干扰与同位素选择进行了研究,用于高性能镍基单晶高温合金的纯净化水平评价。固体样品采用直接进样,通过复杂基体质谱干扰计算判定、共存元素干扰消除等方式,确定了待测元素的同位素和分辨率模式,通过相应标准物质对待测元素的相对灵敏度因子进行校正,采用高流速GDMS测定镍基单晶高温合金中43种痕量元素。结果表明,痕量元素的检出限(3s)为1.04×10^(-7)%~6.60×10^(-3)%,大部分元素的检出限达到0.1μg·g^(-1)级别;对内控标准物质DD6-6#测定6次,测定值的相对标准偏差为0.59%~13%。方法分析结果与不同分析方法对照、标准物质比对,结果吻合度高。     

电感耦合等离子体质谱法测定高纯氧化钽中28种痕量杂质元素

建立了用电感耦合等离子体质谱仪(ICP-MS)测定高纯氧化钽中28种痕量杂质元素的方法。讨论了质谱干扰及接口效应,采用标准加入法消除基体效应。各元素的方法检出限为0.001~0.1μg/g,回收率为90%~115%,方法适用于纯度为99.999%的高纯氧化钽中痕量杂质元素的测定。     

微波消解ICP-MS法测定锂离子电池石墨负极材料中9种痕量元素

建立微波消解–ICP–MS法测定锂离子电池石墨负极材料中Al,Cr,Cu,Fe,K,Na,Ni,Pb,Zn 9种痕量元素含量的方法。采用硝酸–盐酸体系微波消解样品,稀释后用ICP–MS法测定样品消解溶液中9种痕量元素的含量。在优化仪器工作参数后,采用同位素和He模式克服质谱干扰。9种元素的质量浓度与质谱强度具有良好的线性关系,线性相关系数为0.999 1~0.999 8,检出限为0.132~3.700 mg/kg。加标回收率为98.4%~101.0%,测定结果的相对标准偏差为0.3%~3.6%(n=6)。该方法测定结果准确可靠,可用于锂离子电池石墨负极材料中痕量元素的测定。     

恒电流电解—ICP-AES法同时测定高纯铜、铅中15种痕量杂质

本文提出用恒电流电解技术分离除去基体,JCP AES法同时测定高纯铜和高纯铅中的15种痕量杂质。方法对于基体的分离效率达99.9%以上,痕量杂质的标准加料回收率在87—106%之间。本法具有干扰小、准确度高、分析速度快、操作简便等优点。     

电感耦合等离子体质谱法同时测定蔬菜中13种痕量元素

采用电感耦合等离子体质谱法同时测定蔬菜中锶、铜、硒、钼、锰、锌、钴、铬、镉、铅、镍、砷和铝等13种痕量元素。对质谱干扰和非质谱干扰进行了校正。13种重金属元素在一定的质量浓度范围内与其信号强度呈线性关系,方法的检出限(3s)在0.000 4~1.5μg·L-1之间。方法应用于蔬菜标准物质的分析,测定值与认定值相符。对芦笋样品平行测定6次,测定值的相对标准偏差在5.3%~9.6%之间。     

微波消解-电感耦合等离子体质谱(ICP-MS)法同时测定土壤中8种重金属元素

采用微波消解-电感耦合等离子体质谱法同时测定土壤中砷、镉、铬、铜、汞、镍、铅、锌8种痕量元素,对质谱干扰和非质谱干扰进行了校正。8种重金属元素在一定的质量浓度范围内与其信号强度呈线性关系,方法的检出限(3s)在0.001 2~0.029μg/L。用加标回收测定其回收率,加标回收率范围在90.0%~96.3%,对土壤样品平行测定6次,测定值的相对标准偏差在2.1%~3.0%。对湛江南柳河附近土壤进行重金属监测,监测结果符合标准要求。     

微波消解-高分辨电感耦合等离子体质谱法(HR-ICP-MS)测定煤炭中35种痕量金属元素

高分辨电感耦合等离子体质谱可以区分干扰元素和目标元素微弱的质量数差别,能解决大多数多原子、氧化物干扰问题,在煤炭痕量元素分析领域受到关注,但煤炭样品中痕量金属元素尤其是稀土元素受到的质谱干扰挑战未被系统地报道。本文采用HNO3-HF混酸微波消解煤炭样品,优化了消解时间、赶酸、复溶等前处理条件,研究了煤炭中钒、铬、锰、钴、镍、铜、镓、锗、砷、铷、锶、钇、铌、钼、镉、锡、锑、铯、钡、镧、铈、镨、钕、钐、铕、镝、钆、铽、钬、铒、镥、铪、铊、铅、钍共35种痕量金属元素在低、中、高分辨率下的质谱干扰,采用高分辨率模式测定Ge、Nd、Eu、Gd、Ho、Er、Lu,采用中分辨率模式测定Ga,采用低分辨率模式测定其余元素,建立了高分辨电感耦合等离子体质谱测定煤炭中35种痕量金属元素的方法。在优化的实验条件下,各元素标准曲线线性相关系数均在0.9999以上,检出限为0.001~0.082 μg/g。选择煤炭标准样品（SARM 20）进行方法验证,测定结果的相对标准偏差为0.27%~6.27%,测定值与标准值基本一致,标准样品中无认证值的元素进行加标回收试验,加标回收率为85.8%~116.55%。选取俄罗斯其它烟煤、澳大利亚其它烟煤、蒙古炼焦煤、印度尼西亚褐煤、俄罗斯无烟煤、印度尼西亚其它烟煤6个代表性样品进行测试,分析了不同产地煤炭的痕量金属元素含量差异。Mn、Ba、Sr以及稀土元素在6种煤炭中存在显著性差异,可为煤炭原产地溯源分析奠定基础。     

电感耦合等离子体质谱（ICP-MS）法测定垃圾焚烧飞灰中的重金属

基于全自动消解仪优化程序,以HNO3-HF-HClO4消解体系消解飞灰样品,通过选择合适的待测同位素以及干扰元素校正方程校正质谱干扰,建立了全自动消解-电感耦合等离子质谱(ICP-MS)法测定飞灰样品中铍、钒、铬、锰、镍、铜、锌、镉、铅等9种元素的新方法。采用嵌片技术和碰撞模式消除基体干扰,采用单一内标~(103) Rh进行信号漂移校正,9种元素校准曲线的线性相关系数均大于0.999,方法检出限在0.01～0.3μg/g。用飞灰标准物质SRM1633C进行验证,平均相对标准偏差RSD在0.54%～2.4%,加标回收率为85%～120%,各元素的测定值与标准值吻合。方法具有较好的准确度和精密度,适合垃圾焚烧产生飞灰样品中全量金属的测定。     

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。     

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.

     

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。     

Effect of the Method of Modification of Zeolite X on Selectivity of Catalytic Methylation of Toluene

Theoretical and Experimental Chemistry - The effect of the method of modification of catalysts based on zeolite X by cesium and magnesium cations (ion exchange and impregnation) on the selectivity...