GB/T 23944-2023General method for the determination of aluminium in inorganic chemical products—Chromazurol S spectrophotometric method (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 23944-2009 "General method for determination of aluminum in inorganic chemical products Chromium Azur S Spectrophotometric Method". Compared with GB/T 23944-2009, in addition to structural adjustments and editorial changes, the main technical changes are as follows.

a) The detection range has been changed (see Chapter 1, Chapter 1 of the 2009 edition);

b) Changed the mass concentration of chromium azure S solution (see 5.3, 6.2 of the 2009 edition);

c) Changed the mass concentration of cetyltrimethylammonium bromide solution (see 5.4, 6.3 of the 2009 edition);

d) Changed the working curve drawing (see 7.3, 8.3 of the 2009 version);

e) The value (m0) of the mass of aluminum in the blank test solution in the formula is deleted (see Chapter 9 of the 2009 edition).

1 Scope

This document describes the general method for the determination of aluminum in inorganic chemical products, the principle, reagents or materials, and instruments of the chromium azure S spectrophotometric method. Equipment, test procedures, test data processing and tolerances.

This document is suitable for the determination of aluminum content in inorganic chemical products, with a detection range of 0.02µg/mL~0.16µg/mL. In Appendix A Interfering elements are listed.

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 6682 Specifications and test methods for water used in analytical laboratories

HG/T 3696.2 Preparation of standard solutions, preparations and products for chemical analysis of inorganic chemical products Part 2: Impurity standard solutions Preparation of liquid

3 Terms and definitions

There are no terms or definitions to be defined in this document.

4 Principles

After the sample is processed, a solution is formed. In the acetic acid-sodium acetate buffer medium with a pH value of about 5.5, Al3, chromium azure S and hexadecane The reaction of methyltrimethylammonium bromide produces a blue ternary complex, and the absorbance is measured at a wavelength of 640nm with a spectrophotometer to calculate the aluminum content.

5 Reagents or materials

5.1 Test reagents and water. When no other requirements are noted, they should be analytically pure reagents and grade three water specified in GB/T 6682. For testing Impurity standard solutions, unless other requirements are noted, shall be prepared in accordance with the provisions of HG/T 3696.2.

5.2 Acetic acid-sodium acetate buffer solution. pH value is 5.5±0.1, weigh 34.0g sodium acetate (CH3COONa·3H2O) and dissolve it in 450mL In water, add 2.0mL glacial acetic acid and dilute to 500mL with water.

5.3 Chromium Azure S solution. 0.5g/L, weigh 0.100g of Chromium Azure S and dissolve it in 100mL of absolute ethanol, and dilute to 200mL with water.

5.4 Cetyltrimethylammonium bromide solution. 0.5g/L, weigh 0.0500g cetyltrimethylammonium bromide, dissolve in water, and transfer In a 100mL volumetric flask, dilute to the mark and shake gently. Use heat to dissolve if necessary.