Ion microprobe analysis—a review of geological applications

Abstract

In ion microprobe analysis the specimen is bombarded with a focussed ion beam a few #m in diameter and the secondary ions produced are accelerated into the entrance slit of a mass spectrometer. An outline of the salient features of the instrument is given here, together with an account of the methods used for quantitative elemental and isotopic analysis.The major part of this paper consists of a comprehensive account of the geological applications of ion microprobe analysis. These include elemental analysis, especially for trace elements (down to subppm levels in many cases) and light elements (H F) which are beyond the scope of the electron microprobe. The other main area of geological interest is isotopic analysis, where the ion microprobe has the advantage over conventional mass spectrometry of being capable of in situ analysis of selected points on polished sections, obviating the need for laborious specimen preparation, and enabling spatially-resolved data to be obtained, with a resolution of a few #m. The ion microprobe has been especially successful in U Pb zircon dating and the study of isotope anomalies in meteorites. Other significant applications include diffusion and stable isotope studies.

Potentially Hazardous Elements in Coal: Modes of Occurrence and Summary of Concentration Data for Coal Components

“…Quantitative microanalysis techniques currently in use include: I) secondary ion mass-spectrometry (SIMS), in which samples are bombarded by a focused ion beam [9,10]; 2) proton-induced X-ray emission (PIXE), in which samples are bombarded by a proton beam [11-13]; 3) synchrotron-radiation-induced X-ray fluorescence (SXRF), in which samples are placed in a focused beam of highenergy X-rays from a synchrotron source [14][15][16]; 4) laser-ablation inductively-coupled-plasma mass-spectrometry (LA ICP-MS) in which the sample is ablated by a focused Nd/YAG laser, and the ablated material is introduced into a quadrupole mass spectrometer by means of an argon plasma [17][18][19][20]; and 5) electron probe microanalysis (EPMA) in which the sample is bombarded by a focused electron beam, and X-rays at wavelengths characteristic of the elements present are generated and detected [21 -23].…”

CO2 solubility in dacitic melts equilibrated with H2O-CO2 fluids: Implications for modeling the solubility of CO2 in silicic melts

“…Hence, it is convenient to measure the ratio of the peak intensity of the isotope of interest to that of another isotope with well known concentration (e.g., 28 Si in silicates, e.g., Reed, 1989). The so-defined ion yield for each isotope depends not only upon the properties of the isotope itself (mainly the ionization potential) but also on the matrix.…”

Chemical Imaging

“…Secondary ion mass spectrometry (SIMS) has been applied for a long time for the analysis of trace elements and isotopes in geological, extraterrestrial rock samples [35][36][37][38][39] and other abiotic materials 40,41 as well as in biological samples. 40,42,43 In particular, its performance characteristics of high sensitivity, good lateral resolution, the ability to detect basically all elements and isotopes and also the possibility for three-dimensional analysis make it an important technique for chemical imaging.…”