Overview
EN 27627-3:1993 (identical to ISO 7627-3:1983) specifies a flame atomic absorption spectrometry (AAS) method for the chemical analysis of hardmetals. It covers the determination of cobalt (Co), iron (Fe), manganese (Mn) and nickel (Ni) in hardmetal samples in the range 0.01 to 0.5 % (m/m). General requirements on field of application, principle, interferences, apparatus, sampling and reporting are given in ISO 7627‑1.
Key Topics and Requirements
- Scope: Quantitative determination of Co, Fe, Mn and Ni in hardmetals by flame AAS for contents 0.01–0.5% (m/m).
- Sample preparation: Typical test portion ≈ 1 g; dissolution by adding water, hydrofluoric acid then nitric acid with gentle heating until complete dissolution; addition of cesium chloride and ammonium fluoride; transfer to a polypropylene or PTFE container and dilute to prescribed volume (100 mL or 1 000 mL depending on sensitivity).
- Calibration and blanks: Prepare at least six matrix‑matched calibration solutions and one or more blanks. Use high‑purity stock solutions for calibration according to the standard.
- Instrument setup: Optimize spectrometer at element‑specific wavelengths and operating parameters (the standard provides recommended wavelengths and oxidant - e.g., N2O - and guidance on sensitivity and spectral bandpass).
- Measurements: Aspirate blank, calibration and test solutions consecutively; perform at least two measurements per solution; remove burner deposits to avoid sensitivity loss.
- Calculation and reporting: Convert absorbance (blank‑corrected) to mg/L using the calibration curve; calculate % m/m using dilution volume and test portion mass. Permissible deviation between three independent determinations: not to exceed 0.2 × element content (absolute). Report results rounded according to specified rules; if