Determination of Y,Sm, Eu,Gd, Dy,Ho, Er in high purity terbium oxide by ICP-AES

Inductively coupled plasma atomic emission spectrometry (ICP-AES) was employed to determine Y, Sm, Eu, Gd, Dy, Ho and Er in high purity terbium oxide. Terbium oxide was dissolved in 0.5 mol/l HNO₃ and nebulized into the plasma generated by a 56 MHz RF generator at 1.5 kW output power. Using a Jobin-Yvon 1-m Czenry-Turner high resolution, high dispersion scanning monochromator, lines mutually interference-free as well as free of interference from the matrix Tb were chosen for the seven analytes. A set of standards containing the analytes in the concentration range 0.01–1.0 gmg/ml with 1 mg/ml Tb was used for calibration. It was necessary to apply background correction to the gross analyte line intensities in order to obtain linear calibration plots for the analytes.     

Determination of trace elements in human serum by inductively coupled plasma atomic emission spectrometry with flow injection

An analytical method for the simultaneous determination of some trace elements (Au, Fe, Mg, Li, Sr, Zn) in human serum by inductively coupled plasma atomic emission spectrometry (ICP-AES) with flow injection is described. Physical interference caused by the change of sample viscosity is discussed. When 100 μl of serum was injected, the relevant recoveries of > 99% for Li, > 98% for Cu and Mg, > 95% for Fe were obtained for an NIST SRM with R.S.D. > 1.3% using optimized flow injection parameters. The prepared lyophilized control serum for routine analysis in clinical laboratories was analyzed and verified for the validity of the technique employed in this experiment using NIST SRM 909 as a primary reference material.     

Application of laser ablation–inductively coupled plasma-mass spectrometry (LA–ICP–MS) to investigate trace metal spatial distributions in human tooth enamel and dentine growth layers and pulp

Human tooth enamel provides a nearly permanent and chronological record of an individuals nutritional status and anthropogenic trace metal exposure during development; it might thus provide an excellent bio archive. We investigated the micro-spatial distribution of trace metals (Cu, Fe, Mg, Sr, Pb, and Zn) in 196×339 m² raster pattern areas (6.6×10⁴ m²) in a deciduous tooth using laser ablation-inductively coupled plasma-mass spectrometry (LA–ICP–MS). Ablated areas include prenatal and postnatal enamel, the neonatal line, the dentine–enamel junction (DEJ), dentine, and the dentine–pulp junction. Topographic variations in the surface elemental distribution of lead, zinc, strontium, and iron intensities in a deciduous tooth revealed heterogeneous distribution within and among regions. ⁴³Ca normalized elemental intensities showed the following order: Sr>Mg>>Zn>Pb>Fe>Cu. Elevated zinc and lead levels were present in the dental pulp region and at the neonatal line. This study demonstrates the ability of LA–ICP–MS to provide unique elemental distribution information in micro spatial areas of dental hard tissues. Elemental distribution plots could be useful in decoding nutrition and pollution information embedded in their bio apatite structure.Presented in part at the 2002 Winter Conference on Plasma Spectrochemistry, Scottsdale, AZ, January 6–12, 2002. The poster was selected as an outstanding poster presentation.     

New In-situ Sampling and Analysis of the Production of CeO<Subscript>2</Subscript> Powders from Liquid Precursors using a Novel Wet Collection System in a rf Inductively Coupled Thermal Plasma Reactor. Part 1: Reactor System and Sampling Probe

A new reactor and a novel in-situ sampling technique were developed for the study of the synthesis of CeO₂ powders produced from dissolved cerium nitrate salts. The conical reactor minimized particle recirculation and provided a highly symmetrical and undisturbed plasma flow suitable for the analysis of the phenomena affecting the formation of CeO₂ powders. Both a calorimetric study of the reactor and a thermodynamic analysis of CeO₂ formation were conducted. The sampling probe is described and near-isokinetic sampling was achieved. The sampled particles were collected using a miniature wet collection system, i.e. a mist atomizer and a custom-made spray chamber. A numerical simulation of the velocity and temperature fields of the plasma gas in the reactor was done using Fluent. A comprehensive droplet-to-particle formation mechanism presented elsewhere is revisited and expanded based on calorimetry, thermodynamics of CeO₂ formation, numerical simulations and collected particles. No traces of other oxidation states other than CeO₂ were found.     

Size-based analysis of incinerator fly ash using gravitational SPLITT fractionation, sedimentation field-flow fractionation, and inductively coupled plasma-atomic emission spectroscopy

Fly ash has been regarded as hazardous because of its high adsorption of toxic organic and/or inorganic pollutants. Fly ash is also known to have broad distributions of different chemical and physical properties, such as size and density. In this study, fly ash emitted from a solid waste incinerator was pre-fractionated into six sub-populations by use of gravitational SPLITT fractionation (GSF). The GSF fractions were then analyzed by sedimentation field-flow fractionation (SdFFF) and ICP–AES. SdFFF analysis showed the fly ash has a broad size distribution ranging from a few nanometers up to about 50 µm. SdFFF results were confirmed by electron microscopy. Inductively coupled plasma–atomic emission spectroscopy (ICP–AES) analysis of the GSF fractions showed the fly-ash particles contain a variety of inorganic elements including Ca, Si, Mg, Fe, and Pb. The most abundant in fly ash was Ca, followed by Si then Mg. No correlations were found between trace element concentration and particle size.     

毛细管区带电泳分离麦芽寡糖的研究

高效毛细管电泳是近年来分离科学中发展最为迅速的方法之一．它具有分离效率高、所需样品量极少、适合于生物大分子的分离测定和自动化程度高等特点．在毛细管电泳中，区带电泳作为主要的分离模式发挥了重要的作用［1］．本文中以麦芽寡糖类物质为对象，研究了离子流体动力学半径在分离中的作用和规律，提出了麦芽寡糖的迁移时间、淌度与其所含糖基数目的线性关系，并在不同的体系与操作电压下得到了验证．同时，也为利用毛细管电泳技术估算麦芽寡糖所含糖基数提供了简易的途径．1实验部分自行组装毛细管电泳电化学检测系统，高压电源0～30k…     

高效液相色谱-电感耦合等离子体发射光谱联用的瞬时信号采集和处理软件及实际应用

本文对高效液相色谱-电感耦合等离子体原子发射光谱联用技术进行了研究.对所用ICAP-9000型等离子体原子发射光谱仪的控制采样程序进行了部分修改,采集的数据通过异步串行通讯方式由AppleⅡ微机传送至IBM PC286机进行处理。发展的瞬时信号采集程序能满足HPLC的检测要求,并将这一联用技术成功的用于砷的形态分析.     

Determination of Pt in urine of tram drivers by sector field inductively coupled plasma mass spectrometry

The Platinum Group Elements (PGEs) used in automotive catalytic converters are partly emitted into the air during use and can enter the human respiratory system. Due to the increasing use of automotive catalytic converters, the importance of this problem cannot be overlooked.The goal of this investigation was to determine the concentration of Pt in the urine of individuals occupationally exposed to urban air with heavy traffic. Sector field inductively coupled plasma mass spectrometry (SF–ICP–MS) was used for determination of Pt in the urine of tram drivers. 38 and 34 subjects were investigated in Vienna and Budapest, respectively. Samples were taken from the tram drivers both before and after the shift.The results for Pt were compared to those from a previous study performed by our team. The comparison showed that the concentration medians were 4 times higher than the previous ones. Moreover, the values in Budapest were about twice as high as those from Vienna. A partly significant change could be observed between the two sets of data: before, and after the shift.     

Simultaneous multichannel mass-specific detection for high-performance liquid chromatography using an array detector sector-field mass spectrometer

The use of a separation step, such as liquid chromatography, prior to inductively coupled plasma mass spectrometry (ICP–MS) has become a common tool for highly selective and sensitive analyses. This type of coupling has several benefits including the ability to perform speciation analysis or to remove isobaric interferences. Several limitations of conventional instruments result from the necessity to scan or pulse the mass spectrometer to obtain a complete mass spectrum. When the instrument is operated in such a non-continuous manner, duty cycle is reduced, resulting in poorer absolute limits of detection. Additionally, with scanning instruments, spectral skew can be introduced into the measurement, limiting quantitation accuracy. To address these shortcomings, a high-performance liquid chromatograph has been coupled to an ICP–MS capable of continuous sample introduction and simultaneous multimass detection. These features have been realized with a novel detector array, the focal plane camera. Instrument performance has been tested for both speciation analysis and for the elimination of isobaric interferences. Absolute limits of detection in the sub picogram to tens of picograms regime are obtainable, while the added mass dimension introduced by simultaneous detection dramatically increases chromatographic peak capacity.     

微圆盘电极上耦合—级均相反应的稳态电流

在电极袭面反应物浓度均匀的近似假设下,得到了微圆盘电极上暂态可逆反应的一般解.然后利用该一般解得到了微圆盘电极上耦合一级均相反应的可逆电极反应CE、EC、EC′和ECE 的稳态电流计算公式.