Suitability of Mn‐ and Fe‐Rich Reference Materials for Microanalytical Research

Abstract

Manganese- and iron-rich materials are of major geoscientific and economic interest, many of which contain microscopic features that provide valuable information. To obtain accurate results, a homogeneous microanalytical reference material for calibration is needed. Several researchers have used the Mn-and Fe-rich RMs, JMn-1, NOD-A-1, NOD-P-1 and FeMn-1, for this purpose; therefore, they were tested in this study to determine their suitability for microanalysis. Their homogeneity was investigated by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) with two different types of lasers (nano-and femtosecond), with spot and line scan analyses and with different operating parameters, such as spot size, pulse repetition rate and fluence. As the established manganese nodule RMs revealed inhomogeneities for picogram to microgram test portions, we also investigated the new synthetic Fe- and Mn-rich RM, FeMnOx-1. FeMnOx-1 was found to be homogeneous for large (empyt set 40 mu m: 2% RSD repeatability) and small (empyt set 8-10 mu m: 10% RSD repeatability) spot sizes. This homogeneity is in the range of the homogeneous NIST SRM 610 and GSE-1G reference glasses. Furthermore, FeMnOx-1 revealed a large-scale homogeneity within uncertainties of a few per cent, using test portions in the ng range, when measuring four individual mounts of this material

GGR Biennial Critical Review: Analytical Developments Since 2014

“…The USGS, in collaboration with the Max Planck Institute for Chemistry (Jochum et al 2016b, Macholdt et al 2016, applied a precipitation technique to prepare the Mn-Fe-rich MRM FeMnOx-1. This MRM, containing twenty-five trace elements (mass fractions between 20 and 5000 mg kg -1 ), was designed as a calibration material for a wide range of Mn-Fe deposits.…”

Geostandards and Geoanalytical Research Bibliographic Review 2016

“…Byers et al (2016) supply values for up to forty-nine elements in soil RMs, many of which were not characterised by the producer (NIST) making this paper a very useful addition to the existing certificates. In 2016, a new homogenous pressed powder pellet microanalytical RM (FeMnOx-1) for Mn-Fe-rich geological samples was developed by the Max Planck Institute for Chemistry in cooperation with the USGS (Jochum et al 2016b, Macholdt et al 2016.…”

Geostandards and Geoanalytical Research Bibliographic Review 2015

“…In 2016, however, the USGS in cooperation with the Max Planck Institute for Chemistry prepared a Mn-and Fe-rich RM named FeMnOx-1, which can be used for microanalytical purposes as a pressed powder pellet. It is a useful calibration material, for example for Mn-rich samples such as desert varnish or manganese nodules (Jochum et al 2016b, Macholdt et al 2016.…”