GB/T 223.78-2000 in English

《GB/T 223.78-2000钢铁及合金化学分析方法 姜黄素直接光度法测定硼含量》由TC183（全国钢标准化技术委员会）归口，TC183SC5（全国钢标准化技术委员会钢铁及合金化学成份测定分会）执行，主管部门为中国钢铁工业协会。
本标准规定了姜黄素直接光度法测定钢中硼含量。本标准适用于钢中及非合金钢中硼含量的测定。

1 Scope

This standard specifies the determination of boron content in steel by curcumin spectrophotometric method.
This method is applicable to the determination of 0.0005 % (m/m) ~0.012 % (m/m) boron content in steel and 0.0001% (m/m) ~0.0005% (m/m) boron content in non-alloy steel.

2 Normative References

The following documents contain provisions which, through reference in this text, constitute provisions of this standard. At time of publication, the editions indicated are valid. All standards are subject to revision, and parties concerned are encouraged to discuss the possibility of applying the latest edition of the following standards. Members of IEC and ISO support the current effective international standard register.
ISO 385-1: 1984 Laboratory Glassware -- Burettes -- Part 1: General Requirements
ISO 648: 1977 Laboratory Glassware -- One-Mark Pipettes
ISO 1042: 1983 Laboratory Glassware -- One-Mark Volumetric Flasks
ISO 3696: 1987 Water for Analytical Laboratory Use - Specification and Test Methods
ISO 5725-1: 1994 Accuracy (Trueness and Precision) of Measurement Methods and Results -- Part 1: General Principles and Definitions
ISO 5725-2: 1994 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
ISO 5725-3: 1994 Accuracy (Trueness and Precision) of Measurement Methods and Results -- Part 3: Intermediate Measures of the Precision of a Standard Measurement Method
ISO 14284: 1997 Steel and Iron—Sampling and Preparation of Samples for the Determination of Chemical Composition

3 Principle

The sample is dissolved in hydrochloric acid, nitric acid and will decompose to boron compounds (such as nitride) in the action of phosphoric acid and sulfuric acid at 290℃. In the acetic acid-acetate buffer solution, the boric acid and curcumin will form colored compound. The photometric measurement is carried out at 543nm wave length.

Contents
Foreword I
ISO Foreword II
1 Scope
2 Normative References
3 Principle
4 Reagent
5 Instruments
6 Sample Preparation
7 Operation Procedures
8 Result Representation
9 Test Report
Appendix A (Informative)
Appendix B (Informative) Additional Information for International Cooperative Tests
Appendix C (Informative) Diagram of Precision Data
Appendix D (Informative) Additional Precision Test in European Countries
Appendix E (Informative) Explanation for Normative References