摘要 随着高纯材料的需求日益增大，分析这种材料的-辉光放电质谱技术也不断的完善，其中一个困扰业界的问题就是记忆效应，本文采用英国Nu仪器公司的最新型的GD-MS Nu Astrum进行了试验，一种简单的清洗步骤就可以很好的解决这个问题，提高仪器的样品分析通量

This study reports U–Pb geochronological data for zircon obtained by laser ablation-multi-collector-ICP-MS using a new collector block design that includes three ion counters and twelve Faraday buckets. The collector configuration allows for simultaneous detection of ion signals from mass 238U to 203Tl, an important factor for the achievement of highly precise and reproducible Pb–Pb and Pb–U ratios. The main advantage of the multiple ion counting system is the capability to readily measure low Pb ion signals (o1
106 counts per second) resulting from single spot analyses of r40 microns (and corresponding small sample volumes). The latter is an extremely important feature when deciphering multiple domains in complexly zoned zircon populations. A comparative study was conducted between analytical protocols involving non-Tl- and Tl-doped laser ablation runs with regards to evaluating the external reproducibility (i.e., relative standard deviation). The results indicate that the (2s) external reproducibility for both analytical protocols varies between B0.3–1.0% for the 207Pb/206Pb, and ca. 1.3 to o3.0% for the 206Pb/238U (and 207Pb/235U) values. The external reproducibility for the Pb/U values are relatively constant for the Tl-doped analyses, whereas those for the non-Tl runs are inversely correlated with the total absolute (Pb) count rates. The precision and accuracy of both analytical protocols were verified with the analysis of BR266 and 91500 zircon standards and zircons previously dated by ID-TIMS. The instrument configuration and Tl-doping protocol employed here are ideally suited for studies requiring the rapid analysis of a large number (n 4 50) of zircon grains.

Meinhard公司是世界上最早的专业玻璃、石英制品生产商，公司生产的同心雾化器自电感耦合等离子体光谱的出现开始，便为国际上各个公司的ICP、ICP-MS作为标准配置，为全世界用户所使用。

Nu Instruments has developed an instrument with eight channeltrons for Xe multicollection. The channeltrons are positioned to collect simultaneously all the even Xe isotopes; a mass jump may then be made to the two odd isotopes (129 and 131)

There is much discussion these days of Extreme Sports – sports that push the individual to the limits of his or her capabilities. The title of Extreme Microscopy might conjure up similar visions of intrepid and adventurous analysts, but this article is more concerned with situations that push the technique rather than the operator to the limits. “Extreme” in this context also refers to the information depth of the analysis technique. The properties of many modern materials, particularly those developed by the electronics and biomedical industries, depend on their surface chemistry. This will have been carefully engineered, utilising layers of nanometre thicknesses. These materials demand analysis methods that limit information to the extreme or outermost surface, and eliminate unwanted interference from the bulk or substrate. For current and future generations of such materials, only extreme microscopy will do.

For in-situ laser ablation and low level solution analysis of U-Pb measurements, Nu Instruments have developed an optional ‘plug-in’ collector block which allows 204Pb, 206Pb, and 207Pb to be simultaneously measured on ion-counting multipliers whilst measuring 238U and 238U in Faraday collectors (Figure 1). For mass bias corrections simultanoeus measurement of 203Tl and 205Tl can also be made. Using this method, lead blanks and 204Hg isobaric interference corrections can be made by performing an on-peak blank measurement immediately before the sample is introduced into the plasma. This new U-Pb block does not reduce the degree of flexibility for other type of analysis such as hafnium, neodymium etc as only the locations of the ion-counting multiplier slots have been relocated.

Recent advances in mass spectrometry make it possible to utilise isotope variations of transition metals to address some important issues in solar system and biological sciences. Realisation of the potential offered by these new isotope systems however requires an adequate understanding of the factors controlling their isotope fractionation. Here we show the results of a broadly based study on copper and iron isotope fractionation during various inorganic and biological processes. These results demonstrate that: (1) naturally occurring inorganic processes can fractionate Fe isotope to a detectable level even at temperature V1000‡C, which challenges the previous view that Fe isotope variations in natural system are unique biosignatures; (2) multiple-step equilibrium processes at low temperatures may cause large mass fractionation of transition metal isotopes even when the fractionation per single step is small; (3) oxidation^reduction is an importation controlling factor of isotope fractionation of transition metal elements with multiple valences, which opens a wide range of applications of these new isotope systems, ranging from metal-silicate fractionation in the solar system to uptake pathways of these elements in biological systems; (4) organisms incorporate lighter isotopes of transition metals preferentially, and transition metal isotope fractionation occurs stepwise along their pathways within biological systems during their uptake. > 2002 Elsevier Science B.V. All rights reserved.

用NU Plasma， 分析Li同位素，也适合于核工业的同行 Eclogites from Trescolmen, Switzerland, derive from basaltic protoliths that experienced variable degrees of low-T seafloor alteration prior to high pressure metamorphism. N7Li of the eclogites (311 to +5x) ranges to dramatically lower values than observed in fresh MORB, or altered MORB (+4.5 to +14xfor low-T and 32 to +8xfor high-T altered MORB). These low values cannot be explained by fluid interaction with surrounding garnet mica schist, which is generally isotopically heavier (N7Li of +2.4 to +3.8x). The low N7Li values were likely produced by isotope fractionation through Rayleigh distillation during dehydration of clays and/or chlorite at early stages of metamorphism. These data are consistent with isotopically heavy Li being released into the forearc mantle wedge in subduction zones, while an isotopically light component is subducted deeply, and may form a distinct mantle reservoir that could be sampled by plume-related magmas.

介绍用GD-90分析纯铜中超痕量的铅，Pb 204的检出限到20ppt，如果同位素少，或丰度高，检出限可以更低，到1ppt

GD_MS是一种非常成熟的分析技术，适合于高纯材料的分析。采用辉光方电离子源，双聚焦的质量分析器，高灵敏的接收器。可以完成99.9999%以上的分析，它的RSF和IBR技术使分析高纯材料的结果有保证。 国际上都是采用GD-MS作为高纯分析的分析手段

如果二次离子质谱(SIMS)能够降低造价，改进仪器复杂的操作、分析条件，那么这种技术就可能被更广泛运用于半导体制造业中。本文介绍了一种成本较低的小型二次离子质谱仪，用于诊断半导体制造过程中出现的污染问题。利用其快速分析多份砷注入硅片样品，寻找由于离子注入机先前注入其他元素残留而产生污染的证据。通过对这些样品的最表层和表面下约3nm深度的区域下进行分析，发现在所有的样品中都可以检测到硼，但是在其中一个注入机的样品中检测到更高含量的硼和11B同位素，这表明污染物来自离子注入机先前注入物质的残留。总之，这种简化的二次离子质谱可以成为半导体制造业的现场的快速故障诊断工具。

通过使用SIMS对材料纳米涂层进行三维研究，对涂层每一层的成分和大致厚度进行分析，为涂层功能、涂层研究以及涂层失效分析等提供参考。

The global budget for nanotechnology research exceeded $1 billion this year. In the UK, the industries most benefiting from nanoscience and technology are health & life sciences, IT & electronics, defence & aerospace, materials, food & drink, and transport. In the dvelopment of the novel materials demanded by these industries, there is an increasing use of surface engineering to create surfaces with a specific functionality. These tailored surfaces interact with their surroundings in a particular way while leaving the bulk properties of the material such as mechanical strength unaltered. The engineering of surfaces in this way brings with it a need for surface-specific analysis techniques for use in both the research laboratory and the production facility.

MALDI-TOF Mass Spectrometric Analysis of Hydrolysable Tannins is discussed in this article.

The concentration−sensitivity of a MALDI−TOF−MS instrument is traditionally tested by diluting the analyte to the threshold of detection, and measuring the signal to noise ratio (SNR) for the diluted material. Unfortunately, such an experiment measures both the performance of the instrument and the error involved with sample preparation. For example, peptides can stick to dilution containers so reducing the amount of material free in solution and available for analysis.

Methods for assessing the quality of synthetic oligonucleotides must be easy, rapid, and provide adequate identification of failed syntheses using a minimal amount of sample (Williams 1998). MALDI is particularly advantageous in this respect, allowing the analysis of product not detected by traditional PAGE (Williams 1998).

Peptide mass fingerprinting (PMF) makes use of search engine mass−comparisons of trypsin digests to theoretical maps. Not all peptides in a PMF are recognised by simple matching. The work presented here alerts workers to the possible occurrence of metalo−peptides in the PMF’s of metalo−proteins.

The analysis of fragment ions in MALDI post source decay can be observed using a timed ion gate and a reflectron. The reflectron separates the fragment and parent ions by mass. An ideal reflectron allows the collection of the entire mass range of the PSD spectra due to the large energy bandwidth. A theoretical consideration of this produces the following problem :-

The reversible phosphorylation of hydroxyl amino acids is an important method of switching the activity and behaviour of proteins which are key to cellular processes.

Thin layer chromatography (TLC) is used as a rapid and low cost screening of pharmaceutical compound purity. Often the presence of an impurity requires further characterisation by liquid chromatography mass spectrometry (LC-MS), requiring time consuming method development. It is far simpler if the MS characterisation can be performed on the same TLC plate1. SAI has collaborated with experts from Sheffield Hallam University and Pfizer Pharmaceuticals to help develop this technology.

PSD can be used in MALDI−TOFMS to fragment and so sequence a peptide. Fragmentation requires the free movement of a proton along the peptide backbone. Tryptic peptides are difficult to fragment due to their proton sequestering C−terminal (lysine or arginine). A new and novel derivitization places a sulphonated group at the peptides N−terminal. This negatively charged group counteracts the positive group of Lys/Arg. As a result fragmentation via proton mobilisation is improved. We describe here examples of this so called chemically activated fragmentation (CAF).

In order to illustrate the high resolution performance of the Nu Plasma 1700 mass spectrometer the isotope ratios of iron have been measured using Aldrich and Alfa ICP iron standard solutions. There are well known polyatomic interferences of the iron peaks namely, argon oxide, nitride and hydroxide formed in the plasma expansion process which require a resolving power of >2600 to separate them. These interferences can be greatly reduced by using a desolvating nebuliser as the sample introduction system. However, for most of this work, we have decided to enhance the contribution of these interferences to demonstrate the instrument performance, by using a “wet” plasma with shielded torch and running the samples in nitric acid (rather than HCl). In this manner we have been able to increase the level of the ArO peak, which lies adjacent to the 56Fe peak, to a level normally not encountered when using our instruments. Further, all the reported data were obtained by using the true, electronic, baseline, rather than with measurements of blank solutions, which can hide poor resolution performance.

The analysis of calcium on double focusing instruments is generally hindered by the presence of the large 40Ar ion beam. This makes the analysis of 40Ca impossible and can also produce ion beam scattering and the formation ArHH+ that results in a mass 42 molecular interference.