Surface mass spectrometry

Principles and Characteristics Surface mass spectrometry techniques measure the masses of fragment ions which are ejected from the surface of a sample to identify the atoms and molecules present. The techniques are complementary to electron spectroscopy since they provide extra absolute and surface sensitivity and give very specific molecular information. On unknown samples it is common to use a combination of electron spectroscopy and mass spectrometry for surface characterisation. Methods used for surface mass spectrometry are SIMS, SNMS, LDMS, LMMS, LSIMS, GD-MS and LA-ICP-MS. Of these, SIMS is by far the most important for polymer analysis. 

For mass spectrometry the species of interest need to be ionised. Mass spectrometric techniques may be divided into methods with simultaneous evaporation (atomisation) and ionisation processes in the ion source (such as SSMS, ICP-MS, SIMS, LMMS) and methods with post-ionisation processes 

An analytical technique suited for studying surface phenomena like adhesion, friction and wettability must provide molecuiar information with high 

An important difference between SIMS/SNMS and AES/PES is that the analytical information is derived from sputtered particles in the former case and from the surface in the latter case. Both laser microprobe mass spectrometry (LMMS) and static SIMS provide molecular information on local organic and inorganic compounds at variance to AES, 

Surface Analytical Techniques for Polymer/Additive Formulations 

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Inorganic mass spectrometry is described in Section 8.5 related topics are laser mass spectrometry and surface mass spectrometry. In the 37-page review on the analysis of additives by Freitag [2] in 1990, just 13 lines were devoted to mass spectrometry. Later, Batail-lard el al. [3] still dedicate less than a page to MS, although many regard the technique as one of the most important of its kind available today. This monograph... 

A series of examples involving either ESCA (or XPS) or SIMS applied to polymer surface analysis have been collected in the chapter entitled Surface Analysis in the volume by Kroschwitz [7], Surface Mass Spectrometry applied to the field of polymer/additives has been extensively reviewed recently by Bart [8]. 

H. Gnaser, M. R. Savina, W. F. Calaway, C. E. Tripa, I. V. Veryovkin, and M. J. Pellin. Photocatalytic Degradation of Methylene Blue on Nanocrystalline Ti02 Surface Mass Spectrometry of Reaction Intermediates. Int. J. Mass Spectrom., 245(2005) 61-67. 

Another exciting possibility for high sensitivity molecular surface mass spectrometry is the use of laser-excited ion desorption in a pulsed ion cyclotron resonance experiment using Fourier transform techniques. In an ideal situation, this scheme could include all those attributes which are desirable for solid-surface molecular characterization ... 

This paper discusses studies of sea surface films observed and collected in the southern California Bight and the U. S. Middle Atlantic Bight. The goals of these studies were to understand the relationship between chemical composition and surface elasticity in these complex natural films and to determine the range of surface elasticity typical of the ocean surface. Mass spectrometry was the principal analytical tool because of its capacity to characterise and identify chemical structures for many compound classes and to provide a quick assessment of compounds enriched in sea surface films. We present typical variations in SAOM chemical composition as reflected in mass spectral patterns and show the effect of these compositional variations on the film elasticity. 

B. Hagenhoff, D. Rading, Ion Beam Techniques Surface Mass Spectrometry, in Handbook of Surface and Interface Analysis, J. C. Rividre, S. Myhra (Eds.), Marcel Dekker, New York, 19%. 

In tandem with XPS, ToFSIMS is being used to evaluate the coatings as a function of the plasma treatments. The sensitivity of ToFSIMS as a surface mass spectrometry is illustrated in Fig. 5, whereby specific signals characteristic of the anti-bacterial agent can be detected and differentiated from the PET substrate signals. This specificity to chemical and molecular structure can then be exploited in imagii mode. 

The student should be aware that there is another class of surface analysis instruments based on analytical microscopy, including scanning electron microscopy, transmission electron microscopy, atomic force microscopy, and scanning tunneling microscopy. A discussion of these microscopy techniques is beyond the scope of this chapter. Most industrial materials characterization laboratories will have some combination of electron spectroscopy. X-ray analysis, surface mass spectrometry, and analytical microscopy instrumentation available, depending on the needs of the industry. 

Lloyd, K.G., O Keefe, D.P. (2004) Re-discovering surface mass spectrometry chemical mapping from micro to macro. Appl Surf. Sci,231-232,207-216. 

Hagenhoff, B. (1995) Surface mass spectrometry— appheation to biosensor characterization. Biosens. Bioelectron., 10,885-894. 

SIMS is the most commonly used of the surface mass spectrometry techniques. SIMS analyses the secondary ions ejected from a sample following bomhardment with a primary ion beam, usually argon ions. The impact of the primary ion causes an atomic-scale collision cascade within the surface layers of the sample and, at points remote from impact, secondary ions are ejected from the surface. These ions are then determined by MS. 

Busch KL. Desorption ionization mass spectrometry. J Mass Speetrom. 1995 30 233-40. Hanley L, Kornienko O, Ada ET, Fuoco E, Trevor JL. Surface mass spectrometry of molecular species. J Mass Speetrom. 1999 34 705-23. 

Vickerman JC, Swift A (1997) Secondary ion mass spectrometry-the surface mass spectrometry. In Vickerman JC (ed) Surface analysis— the principal techniques. Wiley, New York... 

In 1910 Thomson [ 1J discovered that metals emitted secondary particles when bombarded by his so-called Kanalstrahlen. A small fraction of these "sputtered" particles was found to be charged. Nowadays, the twin techniques of secondary ion mass spectrometry (SIMS) and secondary neutral mass spectrometry (SNMS), both of which are based on Thomson s discovery, belong among the most powerful surface analytical techniques for the compositional characterization of surfaces. In both the surface to be analyzed is bombarded by ions of several keV energy, the so-called primary ions (PI). Depending on whether the masses of the Pl-induced secondary ions or neutrals are analyzed the terms SIMS or SNMS are used. They can be included under the heading surface mass spectrometry since it must be emphasized here that it is a surface and not, e.g.. the gas phase, that is the target for the mass analytical characterization [2]. 

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