ISO 23156:2021

Overview

ISO 23156:2021 specifies an analytical laboratory method for the determination of phosphorus, manganese, chromium, copper and cobalt in ferronickels using inductively coupled plasma optical emission spectrometry (ICP-OES / ICP-OES). The standard covers sample dissolution, reagent and apparatus requirements, instrument performance checks, calibration, measurement and reporting. It applies to all ferronickel grades defined in ISO 6501 and gives the analytical application ranges for each element.

Key application ranges (mass fraction):

• Phosphorus: 0.009 to 0.045 %
• Manganese: 0.02 to 1.0 %
• Chromium: 0.076 to 1.86 %
• Cobalt: 0.24 to 1.4 %
• Copper: 0.02 to 0.07 %

Key topics and technical requirements

• Principle: Dissolution of a test portion with HNO3, HCl and HF, removal of fluorine/silicon with HClO4, dilution, optional internal standard, nebulization and ICP-OES measurement.
• Reagents: Analytical-grade acids (HCl, HNO3, HF, HClO4, H2SO4), high-purity Ni/Fe blanks, multi-element standard solutions and yttrium internal standard solutions.
• Apparatus: PTFE beakers, class A volumetric glassware, polypropylene flasks and an ICP-OES instrument with an appropriate nebulizer (simultaneous or sequential OES accepted).
• Instrument performance: Requirements include selection of wavelengths, spectrometer resolution, short-term stability, background equivalent concentration (BEC) and calibration linearity.
• Sampling & sample prep: Reference to ISO sampling standards for ferronickel (ingots, shot) and specified dissolution and dilution procedures.
• Quality & safety: Includes performance checks, precision and trueness data from interlaboratory tests. Notes safety warnings for hazardous reagents (HF, HClO4).

Applications and users

ISO 23156:2021 is intended for:

• Metallurgical and refining laboratories performing routine quality control of ferronickel.
• Nickel producers and smelters monitoring alloy composition for product specification compliance.
• Third-party testing labs and certification bodies needing standardized ICP-OES procedures for trace/major element analysis.
• Research institutions studying nickel alloys and process optimization.

Practical benefits:

• Consistent, traceable results across labs
• Defined element ranges and validated precision
• Clear guidance for calibration, instrument performance and reporting

Related standards

• ISO 6501 - Grades of ferronickels
• ISO 3696 - Water for analytical laboratory use
• ISO 385, ISO 648, ISO 1042 - Laboratory glassware specifications
• ISO 8049, ISO 8050 - Ferronickel sampling for analysis

Keywords: ISO 23156, ferronickel analysis, ICP-OES, phosphorus determination, metal analysis, nickel alloy testing, laboratory standard, ICP optical emission spectrometry.