Overview
ISO 15586:2003 - "Water quality - Determination of trace elements using atomic absorption spectrometry with graphite furnace" - specifies principles and procedures for measuring low (trace) concentrations of 17 elements (Ag, Al, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Se, Tl, V and Zn) in surface water, ground water, drinking water, wastewater and sediments. The method uses atomic absorption spectrometry (AAS) with electrothermal atomization in a graphite furnace (graphite furnace AAS) and defines sample preparation, chemical modification, calibration, interferences and reporting. Minimum acceptable detection limits for a 20 µl sample volume are given (e.g., Cd ≈ 0.1 µg/L, Pb ≈ 1 µg/L, Zn ≈ 0.5 µg/L, As ≈ 1 µg/L, Se ≈ 2 µg/L).
Key Topics and Requirements
- Principle: Small aliquots (typically 20 µl) are introduced into a graphite furnace; stepwise heating dries, pyrolyzes and atomizes the sample; absorbance is measured at element-specific wavelengths.
- Sample handling: Preservation by acidification, filtration and digestion procedures for sediments and complex matrices; strict cleaning for ultra-trace work.
- Interferences & mitigation: Matrix effects (e.g., high chloride) can cause analyte loss; recommended mitigations include optimized temperature programs, pyrolytic tubes, chemical modifiers (Pd/Mg, Mg(NO3)2, NH4H2PO4, Ni), standard addition and background correction (including Zeeman correction considerations).
- Calibration & quality control: Preparation of multi-level calibration solutions, blank calibration solutions, and guidance on standard storage lifetimes. Characteristic masses, instrument detection limits and optimum working ranges are specified for a 20 µl volume.
- Apparatus & reagents: Guidance on reagent purity (water grade 1), acids (HNO3, HCl), commercial or prepared standards (1000 mg/L stocks), and argon purge/protective gas.
- Documentation: Required reporting elements, precision data and annexes detailing stock preparation, sediment digestion and example instrument settings.
- Safety note: Users must follow normal laboratory safety and national regulations.
Applications and Who Uses It
- Environmental and public health laboratories performing trace metal analysis in water and sediments.
- Water utilities and wastewater treatment facilities monitoring regulatory compliance and treatment performance.
- Regulatory agencies, environmental consultants and researchers conducting monitoring, source tracking and risk assessment.
- Manufacturers and service providers of AAS instrumentation and chemical modifiers.
Keywords: ISO 15586:2003, water quality, trace elements, graphite furnace AAS, electrothermal atomization, detection limits, chemical modifiers, sediment digestion, sample preservation.
Related Standards
- ISO 3696 (Water for analytical laboratory use)
- ISO 5667 series (Water sampling guidance)
- ISO 15587-1 / 15587-2 (Digestion methods for element determination)
This standard is essential when precise, low-level determination of trace metals in aqueous and sediment matrices is required using graphite furnace atomic absorption spectrometry.