ISO 16918-1:2009

Overview

ISO 16918-1:2009 specifies a standardized laboratory method for the determination of five trace elements in steel and iron - tin (Sn), antimony (Sb), cerium (Ce), lead (Pb) and bismuth (Bi) - using inductively coupled plasma mass spectrometry (ICP‑MS). The standard covers sample dissolution (wet digestion), instrument conditioning and measurement, calibration, internal standards and reporting. Applicable mass-fraction ranges are: Sn 5–200 µg/g, Sb 1–200 µg/g, Ce 10–1 000 µg/g, Pb 0.5–100 µg/g and Bi 0.3–30 µg/g. Annex B lists common ICP‑MS interferences relevant to these determinations.

Key topics and requirements

• Scope and principle: Wet digestion of test portion (HCl, HNO3, HF) by microwave or hot-plate, followed by ICP‑MS measurement with peristaltic sample introduction.
• Analytical ranges: Defined mass-fraction ranges for Sn, Sb, Ce, Pb and Bi to ensure method validity at trace levels.
• Reagents and purity: Use high‑purity acids and ultra‑pure water; specific reagent preparations (washing solution, aqua regia, matrix solutions) are specified.
• Sample preparation: Guidelines for sampling, dissolution, blanks and test-solution preparation to minimise contamination.
• Calibration and matrix matching: Calibration blank and solutions must be matrix‑matched to steel (iron matrix solution 10 000 mg Fe/L is defined).
• Internal standards: Use of internal standards (Y, Rh, Lu) to correct for instrument drift and matrix effects.
• Instrumentation: Procedure applicable to quadrupole, magnetic‑sector (high resolution) and TOF ICP‑MS; instrument warm‑up, conditioning and measurement protocols are addressed.
• Measurement specifications: Sections define minimum precision (RSD), limits of detection (LOD) and limits of quantification (LOQ).
• Quality control: Includes preparation of multi‑element standards, mass calibration solutions and guidance on checking reagent purity by mass-spectra scans.
• Interferences: Annex B gives interference information specific to Sn, Sb, Ce, Pb and Bi determinations by ICP‑MS.

Applications and users

ISO 16918-1:2009 is intended for:

• Metallurgical and steel testing laboratories performing trace element analysis for quality control and specification compliance.
• Manufacturers and foundries monitoring alloying and contaminant levels (tin, antimony, cerium, lead, bismuth).
• Regulatory and materials testing bodies requiring reproducible, comparable ICP‑MS results.
• Research institutions studying trace-element behavior in steels and iron. Practical uses include incoming raw-material screening, process control, failure analysis and certification of alloy composition.

Related standards

• ISO 16918-2 (Part 2): Determination of boron, silver, indium and thallium.
• Normative references used in the method: ISO 648, ISO 1042 (laboratory glassware) and ISO 14284 (sampling and preparation of steel and iron).

Keywords: ISO 16918-1:2009, ICP‑MS, steel and iron, trace element determination, tin antimony cerium lead bismuth, wet digestion, matrix-matched calibration, internal standards, LOD LOQ.