Overview
ISO 5960:1984 defines a standardized flame atomic absorption spectrometric (AAS) method for determining cadmium content in cadmium-containing copper alloys listed in International Standards. The method applies to products with cadmium contents between 0,0005 and 2,0 % (m/m). It covers principle, reagents, apparatus, sampling, procedure, result expression and test reporting to support reproducible analytical results for quality control and compliance.
Key Topics
- Principle: Dissolution of a test portion in a fluoroboric-nitric acid attack reagent, followed by aspiration of an appropriately diluted test solution into an air–acetylene flame and measurement of cadmium absorbance at 228.8 nm using a cadmium hollow-cathode lamp.
- Reagents: Use analytical-grade reagents and distilled or equivalent water. The standard specifies a fluoroboric-nitric acid attack reagent and a series of cadmium standard solutions and a copper base solution to prepare calibration-matching standards.
- Apparatus: Ordinary laboratory glassware plus an atomic absorption spectrometer with an air-acetylene burner, a cadmium hollow-cathode lamp, and regulated compressed air and acetylene supplies.
- Sampling: Test samples shall be fine chips or drillings (milling or drilling) with maximum thickness of 0.5 mm.
- Calibration and Measurement:
- Prepare a calibration graph from standard matching solutions that include copper and attack acid to compensate matrix effects.
- Adjust instrument settings (lamp current, wavelength, slit aperture, air and acetylene pressures) and perform preliminary and bracketing measurements.
- Carry out blank tests on reagents and a check test using material of known cadmium content.
- Expression of Results: The standard describes formulae to calculate cadmium concentration in mg Cd per 100 ml of test solution and to convert that to percentage by mass in the sample. The test report must identify the sample, method reference, results and any unusual features.
Applications
- Routine quality control of copper alloys containing trace to minor cadmium levels.
- Verification for specification compliance and material certification in manufacturing and metallurgical supply chains.
- Laboratory method for inter-laboratory comparisons and quality assurance owing to defined sample preparation, calibration and reporting requirements.
Related Standards
- ISO guidance on sampling of copper alloys (note: an International Standard for sampling is indicated as in preparation in the document).
- Other ISO or national standards covering atomic absorption spectrometry practice and laboratory quality management.
Keywords: ISO 5960, cadmium determination, copper alloys, flame atomic absorption spectrometry, AAS, fluoroboric-nitric acid, calibration graph, QC, certification.