New sample holder geometry for high precision isotope analyses

Abstract

Secondary ion mass spectrometry is applied to a wide range of Geoscience applications because of its capability to provide direct in situ measurement of elemental and isotopic composition. The CAMECA IMS 1280 and 1280-HR are large geometry ultra-high sensitivity ion microprobes that provide excellent precision and reproducibility for isotope ratio measurements. A precision at the tenth permil level is routinely achieved for the measurement of 18 O/ 16 O ratio from 10 mm spots using multicollection Faraday Cups. However, analytical artifacts related to the surface topography and to the location of the analysis in the sample (X-Y effects) are known to bias the precision for isotope analysis. The X-Y effects have been investigated using a CAMECA prototype sample holder design. Results show a significant improvement in terms of reproducibility for analyses performed over a large area of the sample. Detailed analytical data using the new sample holder will be presented.

High‐Mg# Olivine, Clinopyroxene and Orthopyroxene Reference Materials for In Situ Oxygen Isotope Determination

“…For each sample, 40–70 mineral grains were collected randomly and embedded in random orientations to form standard epoxy resin SIMS mounts for analysis. Mineral grains were placed within 6 mm from the centre in each mount to avoid possible ‘X‐Y effects’ (Kita et al , Peres et al ). Each mount consisted of one to six samples, and a total of eight mounts were prepared in the Institute of Geophysics and Geology, Chinese Academy Sciences (IGGCAS), Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (GIGCAS) and University of Western Australia (UWA).…”

Biotite Reference Materials for Secondary Ion Mass Spectrometry 18O/16O Measurements

“…, Peres et al . ). The mount used for the calibration of the matrix effect was scanned with a white light interferometer contour GTK‐A (Brucker) in order to determine quantitatively the topography.…”

Predicting instrumental mass fractionation (IMF) of stable isotope SIMS analyses by response surface methodology (RSM)

“…50 In consistency with this fact, the electrostatic deflectors values played a major role regarding the IMF prediction by RSM. Systematic positive trends of IMF vs. the electrostatic deflectors (i.e.…”