Steel, Iron and Alloy — Determination of Cobalt Content — Flame Atomic Absorption Spectrometric Method
Warning: Persons using this part should be familiar with normal laboratory practice. This part does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to ensure compliance with any national regulatory conditions.
1 Scope
This part of GB/T 223 specifies a flame atomic absorption spectrometric method for the determination of the cobalt content in steel and iron.
This part is applicable to the determination of cobalt contents between 0.003% (m/m) and 5.0% (m/m) in steel, iron and alloy.
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 6379.1 Accuracy (Trueness and Precision) of Measurement Methods and Results — Part 1: General Principles and Definitions (GB/T 6379.1-2004, ISO 5725-1:1994, IDT)
GB/T 6379.2 Accuracy (Trueness and Precision) of Measurement Methods and Results— Part 2: Basic Method for the Determination of Repeatability and Reproducibility of a Standard Measurement Method (GB/T 6379.2-2004, ISO 5725-2:1994, IDT)
GB/T 6682 Water for Analytical Laboratory Use — Specification and Test Methods
GB/T 12805 Laboratory Glassware — Burettes
GB/T 12806 Laboratory Glassware — One-mark Volumetric Flask
GB/T 12808 Laboratory Glassware — One-mark Pipettes
GB/T 20066 Steel and Iron — Sampling and Preparation of Samples for the Determination of Chemical Composition (GB/T 20066-2006, ISO 14284:1996, IDT)
ISO 5725-3 Accuracy (Trueness and Precision) of Measurement Methods and Results— Part 3: Intermediate Measures of the Precision of a Standard Measurement Method.
3 Principle
Dissolution of a test portion in hydrochloric and nitric acids, and add perchloric acid until vapour appears. Spraying of the solution into an air-acetylene flame. Spectrometric measurement of the atomic absorption of the 240.7 nm spectral line emitted by a cobalt hollow cathode lamp.
4 Reagents
During the analysis, unless otherwise stated, use only reagents of recognized analytical grade and only grade 2 water as specified in GB/T 6682.
4.1 Pure iron, containing less than 0.0003% (m/m) cobalt.
4.2 Pure nickel, containing less than 0.0003% (m/m) cobalt.
4.3 Hydrochloric acid, ρ about 1.19 g/mL.
4.4 Nitric acid, ρ about 1.42 g/mL.
4.5 Perchloric acid, ρ about 1.67 g/mL.
Foreword II
1 Scope
2 Normative References
3 Principle
4 Reagents
5 Apparatus
6 Sampling
7 Analytical Procedures
8 Expression of Results
9 Test Report
Annex A (Normative) Procedures for the Determination of Instrumental Criteria
Annex B (Informative) Additional Information on International Cooperative Tests
Annex C (Informative) Graphical Representation of Precision Data
