Overview
ISO 5959:1984 defines a precise spectrometric method for the determination of bismuth content in copper and copper alloys using diethyldithiocarbamate complexation. This internationally recognized standard specifies the principle, reagents, apparatus, detailed procedure, and reporting methods to measure bismuth concentrations ranging from 0.00005% to 0.02% by mass in all copper types and alloys listed in other International Standards. The standard ensures accuracy and repeatability in bismuth quantification, which is critical for quality control and compliance in metallurgical processes.
Key Topics
- Applicability: The method targets trace bismuth detection within copper and copper alloys, covering extremely low concentrations between 0.00005% and 0.02% by mass.
- Analytical Principle: Bismuth is separated by precipitation as bismuth hydroxide on manganese dioxide. Then, it is dissolved and extracted as a diethyldithiocarbamate complex in chloroform, with absorbance measured spectrometrically at 405 nm.
- Essential Reagents: Includes ammonia solution, chloroform, manganese nitrate, potassium permanganate, diethyldithiocarbamate sodium solution, among other specific chemical solutions prepared according to the standard.
- Apparatus Requirements: A spectrometer with 50 mm cuvettes calibrated at 405 nm is mandated to measure the absorbance of the bismuth complex.
- Procedure Steps: Sample preparation, dissolution, pH adjustment, precipitation, filtration, dissolution of precipitate, complex formation, organic phase extraction, and spectrometric measurement are all clearly outlined to ensure reproducibility.
- Calibration and Controls: Utilizes standard bismuth solutions in specific concentrations to establish calibration curves, ensuring measurement accuracy. The method includes blank tests and control assays to validate results.
- Result Expression: Final bismuth content is calculated as a percentage mass fraction with a formula accounting for sample mass and measured absorbance values.
- Repeatability & Reproducibility: Statistical data included in the standard demonstrate the method’s reliability across multiple laboratories and sample types.
Applications
- Metallurgical Quality Control: Ensuring the precise monitoring of bismuth levels in copper and copper alloy production helps maintain desired metallurgical properties and compliance with material specifications.
- Material Certification: The method supports certification processes by providing standardized analytical data on trace bismuth content.
- Research and Development: Laboratories engaged in alloy development can use this method to analyze trace elements accurately during experimental phases.
- Corrosion Resistance Evaluation: Accurate measurement of bismuth content aids in assessing the impact of impurities on copper alloy corrosion characteristics.
- Industrial Batch Testing: Routine testing of raw materials and final products for bismuth content using this standard ensures consistent product quality for electrical, plumbing, and architectural copper applications.
Related Standards
- ISO 2338 – Copper and copper alloys - Chemical analysis - Determination of bismuth content by other analytical methods.
- ISO 3677 – Copper and copper alloys - Determination of impurities such as lead and bismuth by atomic absorption spectrometry.
- ISO 12143 – Copper and copper alloys - Chemical analysis - Sample preparation.
- ISO 2204 – Copper and copper alloys - Chemical analysis - Preparation of test samples for spectrometric analysis.
ISO 5959:1984 is an essential reference document for laboratories that require an internationally accepted, detailed, and reproducible method for bismuth determination in copper and its alloys. Its clarity in defining reagents, apparatus, and procedural steps ensures that analyses meet global quality standards and support consistent industrial production.