Spectrometry elemental mass

Operation of quadrupole mass filters operated in higher zones of stability is described with an emphasis on the potential of elemental mass spectrometry by Du et al.19 These quadrupole mass filters allow a mass resolution in the second stability region of up to 9000 and make it possible to resolve a multitude of isobaric interferences. 

Non-elemental mass spectrometry has been increasingly used with HPLC for speciation studies. Tandem mass spectrometry (mass spectrometry-mass spectrometry, MS-MS) has been of particular interest in this area. In this type of system, two mass analysers are needed and it is used as a method of achieving fragmentation of ions generated in the ion source. Arsenic has been speciated by HPLC with ion spray MS-MS (Corr and Larsen, 1996) and Miermans et al. (1997) studied the application of various ionisation methods for the analyses of triphenyltin compounds by MS-MS. 

Ramendik [16] pointed to the possibilities of the creation and development of theoretical foundations based on mathematical modelling in elemental mass spectrometry after the creation of a plasma. For laser plasma mass spectrometry of geological RMs and a quasi-equilibrium approach based on atomisation and ionisation temperatures without relying on reference RMs materials, he claims to be able to arrive at average uncertainties for 40 elements totalling 20% [17]. This may not be ideal but it is a suitable accuracy for solving many practical analytical problems. 

Milgram, K. E. Abatement of spectral interferences in elemental mass spectrometry design and construction of inductively coupled plasma ion sources for Fourier Transform ion cyclotron resonance instrumentation, Ph. D. Thesis, University of Florida, 1997, Diss. Abstr. Int., B 1998, 59(2), 639. 

Elemental mass spectrometry has undergone a major expansion in the past 15-20 years. Many new a, elopments in sample introduction systems, ionization sources, and mass analyzers have been realized. A vast array of hybrid combinations of these has resulted from specific analytical needs such as improved detection limits, precision, accuracy, elemental coverage, ease of use, throughput, and sample size. As can be seen from most of the other chapters in this volume, however, the mass analyzers used to date have primarily been magnetic sector and quadrupole mass spectrometers. Ion trapping devices, be they quadrupole ion (Paul) [1] traps or Fourier transform ion cyclotron resonance (Penning) traps, have been used quite sparingly and most work to date has concentrated on proof of principal experiments rather that actual applications. 

Time-of-Flight Mass Spectrometer Benefits for Elemental Mass Spectrometry... 

Perhaps the greatest attribute that TOF-MS may apply to elemental mass spectrometry is the ability to provide simultaneous multielemental analysis. Of course, a TOF-MS does not record all the masses in the spectrum simultaneously the time difference between adjacent masses is typically in the nanosecond regime. However, all masses are sampled into the mass spectrometer simultaneously and an entire spectrum is generated from each injected ion pulse. Because successively recorded mass spectra are obtainable in short periods in a TOF-MS, especially in instances in which there is a small, well-defined mass range of interest, thousands of mass spectra can be obtained each second. 

M. Wind, I. Feldmann, N. Jakubowski, W. D. Lehmann, Spotting and quantiPcation of phosphoproteins puriPed by gel electrophoresis and laser ablation-element mass spectrometry with phosphorus-31 detection, Electrophoresis, 24 (2003), 1276D1280. 

Wind, M., Edler, M., Jakubowski, N., Linscheid, M., Wesch, H., Lehmann, W.D. Analysis of protein phosphorylation by capillary liquid chromatography coupled to element mass spectrometry with P detection and to electrospray mass spectrometry. Anal. Chem. 73,29-35 (2001)... 

Weber, G., Jakubowski, N., Stuewer, D. Speciation of platinum in plant material. A combination of chromatography, elemental mass spectrometry and electrochemistry. In Zereini, F., Alt, F. (eds.) Anthropogenic platinum-group element emissions. Their impact on men and environment, pp. 183-190. Springer, Berlin (2000)... 

When a pure elemental gas, such as neon, was analyzed by a mass spectrometer, multiple peaks (two in the case of neon) were observed (see Fig. 1.11). Apparently, several kinds of atoms of the same element exist, differing only by their relative masses. Experiments on radioactive decay showed no differences in the chemical properties of these different forms of each element, so they all occupy the same place in the periodic table of the elements (see Chapter 3). Thus the different forms were named isotopes. Isotopes are identified by the chemical symbol for the element with a numerical superscript on the left side to specify the measured relative mass, for example °Ne and Ne. Although the existence of isotopes of the elements had been inferred from studies of the radioactive decay paths of uranium and other heavy elements, mass spectrometry provided confirmation of their existence and their physical characterization. Later, we discuss the properties of the elementary particles that account for the mass differences of isotopes. Here, we discuss mass spectrometry as a tool for measuring atomic and molecular masses and the development of the modern atomic mass scale. 

As in the sources used in optical atomic spectrometry a considerable ionization takes place, they are also of use as ion sources for mass spectrometry. Although an overall treatment of instrumentation for mass spectrometry is given in other textbooks [68], the most common types of mass spectrometers will be briefly outlined here. In particular, the new types of elemental mass spectrometry sources have to be considered, namely the glow discharges and the inductively and eventually the microwave plasmas. In contrast with classical high voltage spark mass spectrometry (for a review see Ref. [69]) or thermionic mass spectrometry (see e.g. Ref. [70]), the plasma sources mentioned are operated at a pressure which is considerably... 

Eiden G. C., Barinaga C. J. and Koppenaal D. W. (1997) Beneficial ion-molecule reactions in elemental mass spectrometry, Rapid Commun Mass Spectrom 11 37-42. 

Wilson D. A., Vickers G. H. and Hieftje G. M. (1987) Use of microwave-induced nitrogen discharge at atmospheric pressure as an ion source for elemental mass spectrometry, Anal Chem 59 1664— 1670. 

Catterick, T., in Trace Analysis A Structured Approach to Obtaining Reliable Results, Chapter 4.3, Elemental Mass Spectrometry, Prichard, E., Mackay, G.M. and Points, J. (eds.), Royal Society of Chemistry, Cambridge, ISBN 0-85404-417-5 (1996). 

Inductively coupled plasma has become the ionization method of choice for elemental mass spectrometry. It was initially developed as the excitation source for multi-element optical spectrometers, because at typical plasma temperatures of 5000-10,000°C virtually all elements on the periodic chart emit detectable light. Most molecules are also atomized at these temperatures, which makes inductively coupled plasma ideal for mass spectrometry monitoring of elemental composition as well. Fassell and co-workers introduced the first inductively coupled plasma interfaced to a mass spectrometer in 1980 (Houk et al., 1980). Elemental mass spectrometry normally requires only low-resolution analysers because unit mass resolution is typically required (i.e. the mass difference between elements, which is always equal to or greater than 1 Da). 

Elemental mass spectrometry using an argon ICP as the ionization source (ICP-MS) is now also widely used for ultratrace determination of elements and is discussed in Chapters 9 and 10. Although ICP-MS complements atomic spectroscopy, it is not a spectroscopic method mass/charge ratio is determined, not radiant energy. 

Hergenroder, R., Samek, O., Hommes, V. (2006) Eemtosecond laser ablation elemental mass spectrometry. Mass Spectrometry Reviews, 25,551-572. 

Ro theoretical resolving power of optical spectrometer RSF relative sensitivity factor in elemental mass spectrometry... 

The sources used for optical atomic spectrometry are also powerful sources for elemental mass spectrometry, from the classical spark source mass spectrometer to present-day plasma mass spectro-metric methods such as glow discharge and inductively coupled plasma mass spectrometry. 

The above methods have opened a new door to tackle quantitative proteomics by element mass spectrometry, although it is still quite difficult to quantify proteins by element mass spectrometry detection after element labeling. In fact, element labeling is not a new concept. For example, a silver saturation assay was applied for measurement of metallothionein in tissue. But this kind of metal-binding assay is based on certain properties of a protein and, being less selective, is applied mainly for a known and isolated protein. Comparatively, bi-functional chelating reagents are established in selective, reproducible reactions and thus are more suitable for protein quantification by element mass spectrometry detection. 

Obviously, the combination of element labeling and then detection by element mass spectrometry is still in its infancy for quantitative proteomics. However, this is such a promising method for metallomics and metallopro-teomics, because of the unique advantages (1) results can be validated due to the traceability of ICP-MS measurement (2) multiplexed analysis is easy to implement because of the availability of so many isotopes for labeling and (3) absolute quantification at a very low concentration allows comparison between the results from different laboratories. 

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