A new form of pure, solid carbon has been synthesized consisting of a somewhat disordered hexagonal close packing of soccer-ball-shaped C60 molecules. Infrared spectra and X-ray diffraction studies of the molecular packing confirm that the molecules have the anticipated 'fullerene' structure. Mass spectroscopy shows that the C70 molecule is present at levels of a few per cent. The solid-state and molecular properties of C60 and its possible role in interstellar space can now be studied in detail.

Solid C60: a new form of carbon

Protein and polymer analyses up to m/z 100 000 by laser ionization time-of-flight mass spectrometry

A new method of desorption ionization is described and applied to the ionization of various compounds, including peptides and proteins present on metal, polymer, and mineral surfaces. Desorption electrospray ionization (DESI) is carried out by directing electrosprayed charged droplets and ions of solvent onto the surface to be analyzed. The impact of the charged particles on the surface produces gaseous ions of material originally present on the surface. The resulting mass spectra are similar to normal ESI mass spectra in that they show mainly singly or multiply charged molecular ions of the analytes. The DESI phenomenon was observed both in the case of conductive and insulator surfaces and for compounds ranging from nonpolar small molecules such as lycopene, the alkaloid coniceine, and small drugs, through polar compounds such as peptides and proteins. Changes in the solution that is sprayed can be used to selectively ionize particular compounds, including those in biological matrices. In vivo analysis is demonstrated.

https://science.sciencemag.org/content/sci/306/5695/471.full.pdf

Mass Spectrometry Sampling Under Ambient Conditions with Desorption Electrospray Ionization

Biomedical surface science: Foundations to frontiers

Highly fluorescent, water-soluble, few-atom noble-metal quantum dots have been created that behave as multielectron artificial atoms with discrete, size-tunable electronic transitions throughout the visible and near infrared. These molecular metals exhibit highly polarizable transitions and scale in size according to the simple relation EFermi/N1/3, predicted by the free-electron model of metallic behavior. This simple scaling indicates that fluorescence arises from intraband transitions of free electrons, and these conduction-electron transitions are the low-number limit of the plasmon—the collective dipole oscillations occurring when a continuous density of states is reached. Providing the missing link between atomic and nanoparticle behavior in noble metals, these emissive, water-soluble Au nanoclusters open new opportunities for biological labels, energy-transfer pairs, and light-emitting sources in nanoscale optoelectronics.

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Highly fluorescent noble-metal quantum dots.

Fundamentals quantitation complementary techniques organic and biological analyses geologic applications depth profiling and semiconductor applications high temperature superconductors metallurgical applications static SIMS and the analysis of polymers instrumentation imaging.

Secondary ion mass spectrometry

Ion-Solid Interaction. Aspects of Quantitative Elemental Sims-Analysis. Instrumentalion. Operational Modes. Application of Sims. Comparison of Sims with Other Analytical Techniques. Developments. Appendix A. Appendix B. Index.

Secondary Ion Mass Spectrometry: Basic Concepts, Instrumental Aspects, Applications and Trends

Ion Formation from Organic Solids

A brief description of studies of the atom-surface interaction using densityfunctional methods is given. The ionization probability of atoms sputtered from metal surfaces is then discussed using results of these studies in conjunction with a resonant tunnelling approach. Good agreement of this theory with experimental data of Yu on the sputtering of adsorbed alkali atoms is obtained. We begin our discussion with a brief outline of the calculation of the groundstate properties of an atom interacting with a metal surface a fixed distance away. [1] We simplify the description of the metal substrate by using the jellium model to represent it: that is, the semi-infinite lattice of positive ions of the metal is smeared out into a semi-infinite homogeneous positive background. This model eliminates much of the detail of the substrate (which is now specified only by the value of its average electron density), but it is able to represent many of the properties of the metal that will interest us here. [1] Our study of the metal-atom system is based on the density-functional theory of inhomogeneous electron systems due to HOHENBERG, KaHN and SHAM. [2] The equations that must be solved self-consistently to obtain the electron density distribution have a Hartree-like form, with a potential that includes not only electrostatic but exchange and correlation effects as well. For the latter we make the commonly used local-density approximation: the relevant exchange and correlation properties in any volume element are taken to be those of a uniform infinite electron gas with a density equal to that in the volume element. [2] When an atom interacts with a system whose electronic states form a continuum, the discrete levels of the atom which are degenerate with the continuum broaden into resonances. The resonances formed in this way when Li, Si and CI atoms interact with a high-electron-density metal are shown in Fig. 1 (at their calculated equilibrium separations). [3] (Explicitly, what is shown is the differ-

Secondary Ion Mass Spectrometry SIMS V

Interaction of nitrogen and ammonia plasmas with polystyrene and polycarbonate studied by X-ray photoelectron spectroscopy, neutron activation analysis and static secondary ion mass spectrometry

Alfred Benninghoven

Papers

Secondary ion mass spectrometry

Secondary Ion Mass Spectrometry: Basic Concepts, Instrumental Aspects, Applications and Trends

Ion Formation from Organic Solids

Secondary Ion Mass Spectrometry SIMS V

Interaction of nitrogen and ammonia plasmas with polystyrene and polycarbonate studied by X-ray photoelectron spectroscopy, neutron activation analysis and static secondary ion mass spectrometry