ISO 22489:2016

Overview

ISO 22489:2016 - "Microbeam analysis - Electron probe microanalysis - Quantitative point analysis for bulk specimens using wavelength dispersive X‑ray spectroscopy" defines procedures and requirements for quantitative elemental analysis by WDS (wavelength dispersive spectroscopy) on an electron probe microanalyser (EPMA) or a scanning electron microscope (SEM) equipped with WDS. The standard covers analysis of a micrometre-sized interaction volume in flat, homogeneous bulk specimens using a normal-incidence electron beam. It explains the principle of analysis, general instrument requirements, specimen preparation, experimental conditions, data acquisition, correction methods and reporting - while not prescribing detailed instrument or software specifications.

Key topics and requirements

• Technique scope: Quantitative point analysis using WDS on EPMA or SEM; applicable for elements Z ≥ 4 (beryllium) with detection limits ranging from ppm to hundreds of ppm depending on matrix and conditions.
• Specimen requirements: Flat, homogeneous bulk specimens; vacuum- and beam-stable; electrically conductive or coated (e.g., carbon ~20 nm); same coating applied to references and unknowns when used.
• Reference materials: Selection guidance to minimize matrix mismatch; follow ISO 14595 for certified reference materials; pure elements commonly used but matrix-matched references are preferred.
• Calibration and stability: Calibration and stability checks for accelerating voltage, probe current (Faraday cup measurement) and X‑ray spectrometer alignment are mandatory for accurate quantification.
• Measurement procedures: Selection of X‑ray lines, measurement of peak and background intensities, probe diameter/scan conditions and analysis position are specified to ensure reproducible results.
• Matrix corrections: Correction methods based on analytical models (Z, A, F - atomic number, absorption, fluorescence) or calibration curve approaches are described; uncertainty estimation and reporting are required.
• Limitations: Intended for flat, homogeneous bulk specimens with normal incidence beam; instrument- and software-specific operational details are to be obtained from manufacturers.

Applications and users

ISO 22489:2016 is practical for:

• Materials scientists and metallurgists performing microchemical composition analysis
• Analytical laboratories conducting quantitative EPMA/WDS measurements
• Semiconductor, ceramics and geoscience labs needing localized bulk composition data
• Quality control and failure analysis where micron-scale compositional quantification is required

The standard supports reliable, traceable WDS quantification workflows, improving repeatability and comparability of EPMA results.

Related standards

• ISO 14594 - Guidelines for determining EPMA experimental parameters (WDS)
• ISO 14595 - Specification of certified reference materials (CRMs)
• ISO/IEC 17025:2005 - Competence of testing and calibration laboratories
• ISO 17470 - Detection limits for microbeam analysis

Keywords: ISO 22489:2016, electron probe microanalysis, EPMA, WDS, wavelength dispersive X‑ray spectroscopy, quantitative point analysis, bulk specimens, specimen preparation, matrix correction, reference materials, calibration.