Water CI+, a new selective and highly sensitive method for the detection of environmental components using ion trap mass spectrometers

A new method for mass spectrometric trace analysis using an ion trap detector is presented based on chemical ionization with water as a reactant. The technique has advantages over the methods commonly used with regard to selectivity and detection limit and it facilitates the detection of unstable organic compounds. Specific applications in the trace analysis of polyaromatic hydrocarbons, trinitroaromatics as well as glycols and their derivatives are described.     

Gas-chromatographische Bestimmung von Wasser

The methods for the determination of trace amounts of water are discussed and the utilization of Porapak as a column material for quantitative analysis of trace water by adsorption gas-chromatography is described. The detection limit for quantitative analysis without preceding concentration is 150 vol.-ppm for the analysis of gases and 1 vol.-ppm for the analysis of liquids.     

Benefits and Malefits of Solvent Vent Mode in Combination with Tandem Mass Spectrometry for Static Headspace Analysis of Organic Solvents by Gas Chromatography

Chromatographia - Static headspace analysis is of value for the detection of volatile compounds present in biological and environmental samples in trace amounts. However, trace compound detection...     

Analysis and interpretation of data from real-time PCR trace detection methods using quantitation of GM soya as a model system

Recent years have seen an increased interest in DNA trace detection methods involved in many areas of bioanalytical research, such as quantitation of genetically modified (GM) ingredients in food products. There is little in the way of standardisation of data handling from these methods, and the data generated needs to be analysed appropriately if the results are to be interpreted correctly. This paper describes particular aspects of real-time PCR trace detection methods in order to increase the understanding of data generated using this bioanalytical technique. Using the specific example of GM soya detection and quantitation, it focuses on the production of calibration curves based on the mean and individual data values, the interpretation of correlation coefficients, regression techniques, and discusses suitable data analysis arising from simple and more complex experimental designs following transformation. By using the approaches outlined in this paper, more accurate analysis of data from real-time PCR and GM trace detection methods could be achieved.     

Optimisation of plasma techniques for trace analysis of refractory metals

Besides atomic absorption spectrometry, the plasma techniques can be seen as state-of-the-art instrumentation in an industrial laboratory for the analysis of trace elements today. For the analysis of refractory metals, e.g. Mo and W, the determination limits which can be reached by ICP-AES techniques are mainly restricted by the spectral background of the matrix. Advantages and disadvantages of sequential and simultaneous detection as well as different methods of evaluation, such as Kaiman filtering and multiple component spectral fitting, are discussed. The results are compared with trace matrix separation techniques and on-line coupling of ion chromatography with ICP-AES and ICP-MS. Furthermore, the limitations of all techniques with respect to their applicability for routine analysis, especially the complexity of sample preparation, degree of automation, time consumption and cost are shown. With respect to the detection capability, TMS with ICP-MS end determination is the most powerful technique, but for routine analysis simultaneous multielement determination from the matrix is favourable.     

A journey through the hazards of possible errors in the analysis of trace elements in body fluids and tissues

Accuracy of the analysis results of trace elements in body fluids and tissues needs to be ascertained during every step of the procedure, starting with the choice of sample, followed by appropriate sampling, analytical methodology and quality assurance, to end with the evaluation of the data. The characterisation of the reference group is important because it is fundamental in the decision making step. Appropriate sampling ensures that the concentration of the trace element in the collected sample is exactly the same as was originally present in the individual. Besides, sample manipulation should not alter the concentrations. The analytical technique chosen is supposed to offer sufficient specificity and sensitivity, and to allow the determination of the trace element with a signal exceeding the quantification limit of detection. Quality assurance through the analysis of similar levels in certified reference materials is a very valuable asset to prove the validity of the detection and to eliminate possible errors which may jeopardize the accuracy and reliability of the data.     

基于表面增强拉曼光谱技术的芥子气模拟剂快速检测方法研究

该文基于具有单分子水平高灵敏度和指纹图谱高分辨率的表面增强拉曼光谱(Surface enhanced Ra-man spectroscopy,SERS)技术,以2-氯乙基乙基硫醚(2-CEES)作为芥子气模拟剂,50 nm金纳米溶胶为SERS基底,系统开展了芥子气模拟剂的快速分析检测方法研究.研究结果表明,该方法对2-...     

Preconcentration by Using Microcrystalline Phenolphthalein for Determining Trace Molybdenum(Ⅵ) in Water by GFAAS

Introduction Molybdenum(Ⅵ) is a biologically essential trace element and its role in an extremely wide variety of systems has been reported. Most common methods often fail to determine trace Mo(Ⅵ) in the analysis of molybdenum-containing samples, due to limitations such as inadequate detection limits and matrix interference, which make the direct determinations impossible.     

On-line coupled ion chromatography-ICP-(AES, MS) and electro thermal vaporisation-ICP-MS in use for ultra trace analysis of high purity rhenium

This work presents the benefits of coupling techniques such as Electro Thermal Vaporisation (ETV)-ICP-MS and Ion Chromatography (IC)-ICP-(AES, MS) for ultra trace analysis in a high purity rhenium powder sample. Direct analysis using ICP-AES suffers from poor detection limits and allows trace analysis only above 1 g/g for most analytes. ICP-MS analysis of trace elements is more sensitive, but signal depression caused by the heavy Re-ions limits trace analysis to concentrations of 50–100 ng/g analyte in the solid sample. Coupling Ion Chromatography with ICP-spectrometers, combined with time resolved measurement (IC-ICP-TRM) of the elution signals, was used to enhance the sensitivity of both ICP-AES and ICP-MS. Resulting detection limits are in the very low ng/g to pg/g range. Coupling of ETV and ICP-MS offers the possibility of eliminating the volatile Re₂O₇ matrix by thermal pretreatment and allows ICP-MS measurements without matrix interferences caused by Re. Results from these methods are compared with Glow Discharge Mass Spectrometry (GDMS) analysis, a semiquantitative solid state technique. The results are also compared with the manufacturers' specifications to show the power of modern routine analysis using ICP-AES or FAAS.     

Hyphenated techniques in anticancer drug monitoring. I. Capillary gas chromatography-mass spectrometry

Muramic acid (Mur) is present in the cell wall of Eubacteria and serves as a chemical marker for the trace detection of bacteria and bacterial cell wall debris in complex matrices. There have been numerous studies using a variety of derivatives of Mur, particularly in combination with gas chromatography-tandem mass spectrometry (GC-MS-MS) where the detection limit has been steadily lowered. A stable, halogenated derivative, the pentafluorobenzyl oxime (PFBO) acetate of Mur, has been developed by others and successfully used for GC with electron-capture detection. The current report is the first use of this derivative for GC-MS-MS analysis of Mur, or indeed any other carbohydrate, using negative ion chemical ionization (NICI) with GC-MS-MS. Mur was readily detected in settled surface dust (166 ng/mg), as well as dust collected from indoor air (1.4-5.9 ng/mg). Analyses of Mur as a PFBO acetate by GC-NICI-MS-MS or as alditol acetates by electron impact GC-electron impact ionization MS-MS serve as complementary approaches for trace detection in complex matrices.     

Headspace single drop microextraction combined with HPLC for the determination of trace polycyclic aromatic hydrocarbons in environmental samples

A new method by combining headspace single drop microextraction (HS-SDME) with HPLC fluorescence detection for the determination of trace polycyclic aromatic hydrocarbons (PAHs) in environmental samples was developed. Aqueous solution of saturated beta-cyclodextrin was used as extraction solvent and five PAHs were employed as target analytes. The factors affecting the extraction efficiency were studied in detail and the optimal extraction conditions were established. Beta-cyclodextrin was found to play two important roles, one is the improvement of extraction efficiency of target analytes and the other is the enhancement of their fluorescence intensities in HPLC fluorescence detection. The detection limits for the target analytes were found to be in the range of 0.004-0.247ng/ml and the relative standard deviations (R.S.D.s) of 5.1-7.1% were obtained. The proposed method was applied to the analysis of trace PAHs in environmental samples with satisfactory results.     

Aktivierungsanalytische Bestimmung des Sauerstoffs in Werkstoffen der Elektronik

The rapid determination of oxygen by activation analysis with a Hungarian neutron generator in materials used in electronics is reported. The instrumentation and experimental technique as well as the results of the trace analysis of oxygen in Al, Cu, Ag, Au, Nb, Ta, Zr and Se and of the investigation of oxygen distribution between surface and volume are described, indicating the detection sensitivity and accuracy. The possibilities of improving the detection sensitivity are discussed.      

Status and future prospects for use of the graphite furnace for elemental trace analysis of liquids and solids

Summary An overview of the versatility and use of the graphite furnace for elemental trace analysis of liquids and solids using spectrochemical detection is presented. The analytical performance of conventional graphite furnace atomic absorption spectrometry is compared to other popular state of the art spectrochemical techniques with respect to detection power, precision, sample compatibility and throughput. Some applications of the graphite furnace to practical problem solving in trace analysis are highlighted, including its use with atomic absorption, coherent forward scattering, laser excited atomic fluorescence, laser enhanced ionization and coupled methodologies. Prospects for future use and evaluation are given.     

Topical Problems in Elemental Analysis of Advanced Ceramic Materials

Selected prominent problems in the analysis of advanced ceramic materials are surveyed. The importance of reliability of results is discussed in the field of elemental trace- and microanalysis in view of its interaction with economy, power of detection, local resolution and speciation selectivity. Particular problems in the analysis of major constituents, trace components and microlocal distributions are based on the striking propertics of ceramics; they are exemplified. Analytical assistance must start from the beginning of the production processing, in the preparation of the powdered base materials. Determination of the stoichiometry requires high accuracy and differentiation of chemical species in bulk and surface analysis of ceramic base powders. Element trace determination by direct instrumental methods requires standard reference materials for calibration; these are currently inavailable in a sufficient variety. For optimum reliability and power of detection, element traces must be prepared in isolated form in a small excitation volume for analysis. A review on the state-of-the-art of wet-chemical combined procedures is presented. Decomposition position procedures are emphasized, due to their risk of contributing severe systematic error. Combustion in elementary fluorine is presented for decomposition of refractory materials. The performance of some direct procedures is discussed. Very efficient methods are available for element trace determinations in ceramic materials, offering high detection power. Several approaches for high-resolution local microanalysis in non-conductive ceramic materials are identified as the most promising development in the analysis of sintered compact ceramic products and devices.     

Determination of neptunium in plutonium materials by ICP-MS

An ICP-MS analytical method as an alternative to the current radiochemical method was developed to analyze trace level ²³⁷Np in bulk plutonium materials. In this method, ²³⁷Np is determined together with a suite of trace elements during a single analysis using one dissolution solution. Method validation was achieved through precision examination, spike recovery study, detection limit determination, comparison of results with the radiochemical method, and laboratory intercomparison studies on Pu metals. The ICP-MS method significantly reduced the analysis cost, the sample amount, consumption of chemicals and waste generation, as well as the sample turnaround time.     

PID—100C型光离子化气相色谱仪的研制与应用

作者研制一种微机化光离子化气相色谱仪，其灵敏度和检出限优于ＦＩＤ两个数量级（苯）可用于有机挥发物痕量分析。     

Automated analysis of volatile halogenated hydrocarbons in rainwater and ambient air by purge and trap capillary gas chromatography

An automated system employing a purge and trap technique with capillary gas chromatography and electron-capture detection (ECD) has been developed for the analysis of trace levels of volatile halogenated hydrocarbons and applied to the determination of the compounds in environmental samples such as rainwater and ambient air. The operation of the method, its application to environmental samples, and the results obtained are described. Use of the system ensured good chromatographic resolution and high accuracy, even with trace levels of the compounds.     

Laser-induced breakdown detection combined with asymmetrical flow field-flow fractionation: application to iron oxi/hydroxide colloid characterization

The combination of asymmetrical flow field-flow fractionation (AsFlFFF) with the laser-induced breakdown detection (LIBD) is presented as a powerful tool for the determination of colloid size distribution at trace particle concentrations. Detection limits (D1) of 1, 4, and 20 microg/L have been determined for a mixture of polystyrene reference particles with 20, 50, and 100 nm in size, respectively. This corresponds to injected masses of 1, 4, and 20 pg, which is lower than found in a previous study with the symmetrical FlFFF (SyFlFFF). The improvement is mainly due to the lower colloid background discharged from the AsFlFFF channel. The combined method of AsFlFFF-LIBD is then applied to the analysis of iron oxi/hydroxide colloids being considered as potential carriers for the radionuclide migration from a nuclear waste repository. Our LIBD arrangement is less sensitive for iron colloid detection as compared to reference polystyrene particles which results in a detection limit of approximately 240 microg/L FeOOH for the AsFlFFF-LIBD analysis. This is superior to the detection via UV-Vis absorbance and comparable to ICP-MS detection. Size information (mean size 11-18 nm) for different iron oxi/hydroxide colloids supplied by the present method is comparable to that obtained by sequential ultrafiltration and dynamic light scattering. A combined on-line ICP-MS detection is used to gain insight into the colloid-borne main and trace elements.     

基于CiteSpace的磁性SERS检测技术研究态势分析

表面增强拉曼光谱(SERS)具有灵敏度高、特异性强、操作简便、快速等优点,已成为近年来最有前景的分析工具之一.磁性纳米材料将贵金属的独特性能和磁性结合在一起,作为SERS基底检测痕量目标物被广泛研究.本文以1990～2020年间WOS核心数据库在SERS磁性纳米基底这一领域检索到的805条记录为研究对象,运用文献计量可...     

稀土掺杂上转换纳米材料在兽药残留检测领域的应用

食品和环境中兽药残留问题时有发生,对人类健康构成很大的潜在威胁。随着人们对美好生活和同一健康的向往和不断追求,对微量甚至痕量兽药残留的分析检测已显得日益迫切和重要。因此,构建对兽药残留进行灵敏、准确、稳定、简便、快速检测的方法已成为一个热点研究领域。稀土掺杂上转换纳米材料(REEs-UCNPs)作为一种新兴的纳米荧光材料,具有独特的反斯托克斯发光性质,由于其具有荧光寿命长、光散射小、激发光生物组织穿透深度大且对组织损伤小等显著优点,在分析检测领域逐步凸显出巨大优势。本文重点介绍了基于REEs-UCNPs构建荧光共振能量转移核酸适配体传感器、磁性纳米颗粒结合核酸装配体传感器、荧光免疫探针以及现场快速检测等在兽药残留检测方面的研究进展,并对其应用前景进行了探讨和展望。