Overview
ISO 15353:2001 specifies a validated laboratory method for the determination of tin (Sn) in steel and iron using flame atomic absorption spectrometry (FAAS) after chemical extraction as the Sn–SCN complex. The method is applicable to tin concentrations from 0.001% to 0.1% by mass and provides step‑by‑step procedures for sample dissolution, complex formation, solvent extraction, instrumental measurement and calibration.
Key topics and technical requirements
- Principle: Dissolve a weighed test portion in hydrochloric and nitric acids, form the tin–thiocyanate complex, extract into 4‑methyl‑2‑pentanone (isobutyl methyl ketone) and aspirate the organic phase into a dinitrogen‑monoxide/acetylene flame for FAAS measurement at 224.6 nm using a tin hollow‑cathode lamp.
- Reagents & standards: Specifies analytical reagents (HCl, HNO3, formic acid, ascorbic acid, KSCN, isobutyl methyl ketone) and preparation of tin standard solutions (stock 1 g/L, dilutions for calibration).
- Apparatus & performance:
- Instrument optimization and settings (red‑feather flame ~20 mm, no background correction).
- Performance checks: short‑term stability, limit of detection (better than 0.1 µg/ml in inorganic solution), linearity and characteristic concentration (better than 0.4 µg/ml in organic solution).
- Volumetric glassware per ISO 648 / ISO 1042 and sampling per ISO 14284.
- Procedure: Test‑portion sizes depend on expected Sn content (e.g., 1.00 g for 0.001–0.025% Sn). Includes blank runs, extraction steps, washing, filtration and preparation of calibration series.
- Calibration & results: Calibration graphs prepared for each series; corrections applied for blanks. Results expressed as % Sn by mass. Precision was assessed by an interlaboratory study and treated in accordance with the ISO 5725 series.
Applications - who uses this standard
- Metallurgical and materials testing laboratories performing chemical composition analysis of steels and irons.
- Steel producers and alloy manufacturers for quality control and product certification.
- Inspection bodies and conformity assessment laboratories needing an ISO‑recognized method for tin quantification.
- Analytical scientists looking for a FAAS procedure optimized for low‑level tin in ferrous matrices.
Related standards
- ISO 14284 - sampling and sample preparation for chemical composition of steel and iron.
- ISO 3696 - water for analytical laboratory use.
- ISO 648 / ISO 1042 - laboratory volumetric glassware.
- ISO 5725 series - accuracy (trueness and precision) of measurement methods and results.
Keywords: ISO 15353:2001, tin determination, flame atomic absorption spectrometry, FAAS, Sn‑SCN extraction, steel and iron analysis, analytical method, calibration, limit of detection.