GB/T 6324.12-2023Test method of organic chemical products—Part 12: Determination of trace mercury in organic liquid products—Atomic fluorescence spectrometric 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 is Part 12 of GB/T 6324 "Test Methods for Organic Chemical Products". GB/T 6324 has released the following parts.

---Part 1: Water miscibility test of liquid organic chemical products;

---Part 2: Determination of dry residue after evaporation of volatile organic liquids on a water bath;

---Part 3: Determination of reduced potassium permanganate substances;

---Part 4: Determination of trace sulfur in organic liquid chemical products by microcoulometric method;

---Part 5: Determination of carbonyl compound content in organic chemical products;

---Part 6: Determination of liquid colorimetry by tristimulus value colorimetry;

---Part 7: Determination of melt colorimetry;

---Part 8: Determination of moisture content of liquid products by Karl Fischer Coulombometry;

---Part 9: Determination of chlorine;

---Part 10: Determination of trace sulfur in organic liquid chemical products by UV fluorescence method;

---Part 11: Determination of trace amounts of arsenic in liquid chemical products by atomic fluorescence method;

---Part 12: Determination of trace amounts of mercury in organic liquid chemical products by atomic fluorescence method.

Introduction

GB/T 6324 aims to establish unified test methods for organic chemical products involving many inspection items, and along with the analysis technology Update and improve the development and maturity of the project and the universality of test project requirements. This series of standards consists of the following twelve parts.

---Part 1: Water miscibility test of liquid organic chemical products;

---Part 2: Determination of dry residue after evaporation of volatile organic liquids on a water bath;

---Part 3: Determination of reduced potassium permanganate substances;

---Part 4: Determination of trace sulfur in organic liquid chemical products by microcoulometric method;

---Part 5: Determination of carbonyl compound content in organic chemical products;

---Part 6: Determination of liquid colorimetry by tristimulus value colorimetry;

---Part 7: Determination of melt colorimetry;

---Part 8: Determination of moisture content of liquid products by Karl Fischer Coulombometry;

---Part 9: Determination of chlorine;

---Part 10: Determination of trace sulfur in organic liquid chemical products by UV fluorescence method;

---Part 11: Determination of trace amounts of arsenic in liquid chemical products by atomic fluorescence method;

---Part 12: Determination of trace amounts of mercury in organic liquid chemical products by atomic fluorescence method.

Test methods for organic chemical products Part 12: Trace amounts of mercury in organic liquid chemical products atomic fluorescence method Warning---Some reagents used in this document are toxic or corrosive, and some operations are dangerous. This document does not disclose the There are possible safety issues. Users should strictly follow relevant regulations for correct use and are responsible for taking appropriate safety and health measures.

1 Scope

This document describes a method for the determination of trace amounts of mercury in organic liquid chemical products using atomic fluorescence.

This document is applicable to the determination of trace amounts of mercury in organic liquid chemical products such as hydrocarbons, alcohols, and acids.

When the weighed sample amount is 1.0g and the fixed volume is 50mL, the detection limit of the method in this document is 0.001mg/kg.

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 3723 General Safety Principles for Sampling Industrial Chemical Products

GB/T 6680 General rules for sampling of liquid chemical products

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

GB/T 33087 Specifications and test methods for high-purity water for instrumental analysis

3 Terms and definitions

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

4 Method Principle

Digest the sample with potassium permanganate and potassium persulfate in a sulfuric acid-nitric acid medium under heating conditions. All mercury contained in the digested sample Converted into divalent mercury, hydroxylamine hydrochloride reduces the excess oxidant, and potassium borohydride reduces divalent mercury into atomic mercury, which is brought into the atomizer by the carrier gas, under the irradiation of a mercury hollow cathode lamp, the ground state mercury atoms are excited to a high energy state. When deactivated and returned to the ground state, fluorescence of characteristic wavelength is emitted.

Light, its fluorescence intensity is proportional to the mercury concentration in the tested solution within a certain range. Compared with the standard series of solutions, the mercury concentration in the sample can be measured content.

5 General provisions

5.1 Unless otherwise stated, the reagents used in this document are all high-grade pure reagents, and the test water is high-purity water specified in GB/T 33087.

5.2 The digestion inner tank and glassware of the pressure digester should be soaked in nitric acid solution for at least 24 hours, and rinsed with high-purity water before use.