GB/T 23671-20232-Hydroxy-6-naphthoic acid (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents" Drafting.

This document replaces GB/T 23671-2009 "2-Hydroxy-6-naphthoic acid". Compared with GB/T 23671-2009, apart from structural adjustment and editorial changes, the main technical changes are as follows:

---Added terms and definitions (see Chapter 3);

---Changed the quality requirements for 2-hydroxy-6-naphthoic acid (see Chapter 4, Chapter 3 of the 2009 edition);

---Changed the sampling volume (see Chapter 5, Chapter 4 of the 2009 edition);

---Changed the appearance assessment method (see 6.2, 5.2 of the 2009 version);

---Added instrumental method for melting point determination (see 6.3.2);

---Changed the chromatographic analysis conditions (see 6.4.4.5, 5.4.4 of the 2009 edition);

---Changed the weighing sample amount for ash content determination (see 6.5, 5.5 in the 2009 version);

---Changed the weighing amount for determination of alkali-insoluble matter content (see 6.7, 5.7 of the 2009 edition);

--- Added methods for determination of metallic iron, potassium, sodium content and total calcium and magnesium content (see 6.8);

---The content of the logo has been changed (see 8.1, 7.1.1 of the 2009 version).

1 Scope

This document specifies the requirements, sampling, test methods, inspection rules, as well as marking, labeling, packaging, transportation and storage.

This document applies to the quality control of 2-hydroxy-6-naphthoic acid products.

Molecular formula: C11H8O3

Relative molecular mass: 188.18 (according to 2021 international relative atomic mass)

CAS number: 16712-64-4

2 Normative reference documents

The contents of the following documents constitute essential provisions of this document through normative references in the text. Among them, the dated quotations For undated referenced documents, only the version corresponding to that date applies to this document; for undated referenced documents, the latest version (including all amendments) applies to this document.

GB/T 2381-2013 Determination of insoluble matter content of dyes and dye intermediates

GB/T 2384-2021 General method for determination of melting point range of dye intermediates

GB/T 2386-2014 Determination of moisture content of dyes and dye intermediates

GB/T 6678-2003 General principles for sampling of chemical products

GB/T 6682-2008 Specifications and test methods for water used in analytical laboratories

GB/T 8170-2008 Numerical rounding rules and representation and determination of limit values

GB/T 15337-2008 General principles of atomic absorption spectrometry

GB 20814-2014 Limits and determination of heavy metal elements in dye products

GB/T 21876 Determination of ash content of solvent dyes and dye intermediates

3 Terms and definitions

The following terms and definitions apply to this document.