Overview
ISO 17058:2004 defines a standardized spectrophotometric method for determination of arsenic content in steel and iron. The method covers measurement after chemical digestion and distillation and is applicable to arsenic mass fractions from 0.0005% to 0.10%. The procedure produces a molybdenum‑blue complex measured at approximately 840 nm, enabling quantitative arsenic determination for metallurgical quality control and certification.
Key topics and requirements
- Scope and applicability: Arsenic in steel and iron within the specified range (0.0005%–0.10% mass fraction).
- Analytical principle: Dissolve sample in HCl/HNO3, oxidize with H2SO4, reduce arsenic to As(III) and distil as chloride; capture and re‑oxidize to As(V); form the ammonium molybdate–arsenic complex reduced by hydrazine sulfate (molybdenum blue) and measure spectrophotometrically (~840 nm).
- Reagents and solutions: Detailed preparations for acid mixtures, reductant powder (hydrazine sulfate + KBr), ammonium molybdate, and calibrated arsenic standard solutions (stock and working standards).
- Apparatus and glassware: Class A volumetric glassware (ISO 385‑1, ISO 648, ISO 1042), specified distillation setup and a spectrophotometer with 40 mm or 10 mm cells.
- Sampling and sample sizes: Test portion masses vary with expected arsenic level (e.g., 1.0 g for very low levels down to 0.10 g for higher levels).
- Calibration and blanking: Establish a calibration graph through prepared standard solutions; include blank tests and net absorbance correction.
- Quality parameters: The standard includes precision data (repeatability and reproducibility) and references ISO 5725 series for statistical evaluation.
Applications and users
ISO 17058:2004 is used by:
- Metallurgical and materials testing laboratories for impurity analysis in steel and iron.
- Steel producers and foundries for in‑process quality control and final product certification.
- Quality assurance and compliance teams ensuring alloy specifications and customer/regulatory requirements for arsenic content.
- Failure analysis and R&D labs investigating effects of trace arsenic on material properties.
Typical applications include routine batch testing, incoming raw‑material inspection, certification of alloy composition, and trace contaminant monitoring.
Related standards
- ISO 14284 - Sampling and preparation for chemical composition analysis
- ISO 3696 - Water for analytical laboratory use
- ISO 385‑1, ISO 648, ISO 1042 - Class A volumetric glassware specifications
- ISO 5725 series - Precision of measurement methods and results
Keywords: ISO 17058:2004, arsenic determination, spectrophotometric method, steel and iron, arsenic content, distillation, molybdenum blue, calibration graph, repeatability, reproducibility, metallurgical laboratory.