ISO 23380:2022

Overview

ISO 23380:2022 - Coal - Selection of methods for the determination of trace elements - Guidance and requirements provides guidance and requirements for selecting analytical methods to determine trace elements in coal. The standard covers elements of environmental and regulatory interest (for example arsenic, mercury, selenium, lead, chromium, nickel, zinc, boron, chlorine, fluorine), and notes that the radioactive elements thorium and uranium can also be considered. ISO 23380:2022 gives procedural guidance on sample preparation (ashing, digestion), method selection and quality assurance but does not prescribe specific analytical methods for individual elements.

Key topics and requirements

• Scope and element list: Identifies trace elements of interest and includes optional radionuclides (Th, U).
• Sample preparation: Discusses moisture determination (ISO 11722), ashing procedures (maximum 500 °C ramping rules, ISO 15238) and alternative dissolution techniques (Annex B) for unashed coal.
• Analytical techniques: Summarizes applicable techniques - ICP-AES/ICP-OES, ICP-MS, AAS/GFAAS, AFS, XRF, ion chromatography (IC), ion-selective electrodes (ISE) - and highlights where each is most appropriate (e.g., ICP-MS for ultra-trace antimony, cadmium, thorium, uranium).
• Element-specific guidance: Provides discussion on arsenic/selenium (hydride techniques, ISO 11723), boron, chlorine (combustion/pyrohydrolysis, ISO 587 / ISO 18806 / ISO 13605), fluorine (ISO 11724), and mercury (ISO 15237 and alternative combustion/adsorption techniques).
• Quality assurance: Strongly emphasizes use of certified reference materials (CRMs) (see ISO Guide 33) and method verification using ISO 5725 procedures. A CRM should accompany each analytical batch and be reported.
• Calculations & reporting: Includes formulae for expressing results on dry/ash bases and requirements to determine ash yield when ashing is used.

Applications and users

ISO 23380:2022 is intended for:

• Laboratories performing routine or research trace-element analysis of coal and coke.
• Environmental monitoring and compliance programs assessing emissions or pollutant inventories.
• Coal producers, utilities and fuel quality teams managing feedstock specifications and combustion impacts.
• Regulatory bodies and consultants developing sampling/testing strategies or audit protocols. Practical uses include selecting appropriate instrumentation (e.g., ICP-MS vs ICP-AES), designing sample-preparation workflows (avoid loss of volatile elements), and establishing QA procedures with CRMs.

Related standards

Relevant references and complementary standards cited in ISO 23380:2022:

• ISO Guide 33 (CRMs)
• ISO 11722 (moisture)
• ISO 15238 (ashing)
• ISO 11723 (arsenic/selenium)
• ISO 11724 (fluorine)
• ISO 15237 (mercury)
• ISO 13605 (XRF)
• ISO 5725 (method verification)
• ASTM D6357, ASTM D6414, ASTM D6722 (method guidance)

This guidance document helps labs and stakeholders make informed method selection decisions for reliable, comparable coal trace-element data.