GB/T 7717.12-2022Acrylonitrile for industrial use—Part 12: Determination of purity and impurities—Gas chromatographic method (English PDF)

Foreword

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

This document is part 12 of GB/T 7717 "Acrylonitrile for Industrial Use". GB/T 7717 has released the following parts.

--- Part 1: Specifications;

--- Part 5: Determination of acidity, pH value and titration value;

--- Part 8: Spectrophotometric method for the determination of total aldehyde content;

--- Part 9: Determination of total cyanide content by titration;

--- Part 10: Spectrophotometric method for the determination of peroxide content;

--- Part 11: Spectrophotometric method for the determination of iron and copper content;

--- Part 12: Determination of purity and impurity content by gas chromatography;

--- Part 15: Determination of p-hydroxyanisole content;

--- Part 16: Determination of iron and copper content by graphite furnace atomic absorption spectrometry and inductively coupled plasma mass spectrometry.

This document replaces GB/T 7717.12-2008 "Industrial Acrylonitrile Part 12: Determination of Purity and Impurity Content by Gas Chromatography Compared with GB/T 7717.12-2008, in addition to structural adjustment and editorial changes, the main technical changes are as follows.

a) Changed the scope and re-specified the detection limit of the method (see Chapter 1, Chapter 1 of the 2008 edition);

b) Changed the column specifications and chromatographic conditions, and added a new FFAP capillary column (60m×0.32mm×1.0µm) and chromatographic conditions (see 6.2, 7.1 of the 2008 edition);

c) Added the chromatographic conditions for the determination of low-level impurities (see 6.2);

d) The quantification method adds the correction area normalization method (see 4.2, 8.3);

e) added alternatives for the correction factors for acrolein, propionitrile and methacrylonitrile (see 8.2.3, 8.3.3.);

f) Changed the type of impurities deducted in the purity calculation formula (see 8.2.3, 8.1.2 of the 2008 edition);

g) Re-determined the repeatability limit of the method and increased the reproducibility limit (see Chapter 10, Chapter 9 of the 2008 edition);

h) quality control was added (see Chapter 11);

i) The original Appendix A was deleted. In the added Appendix A, the relative mass of acrylonitrile to toluene (internal standard) is specified when using the internal standard method For the calculation method of correction factor, add chromatogram A.1 (see Appendix A, Appendix A of the 2008 edition).

Introduction

GB/T 7717 "Industrial Acrylonitrile" includes product standards and supporting method standards for industrial acrylonitrile. In order to facilitate management and use, It consists of the following parts.

--- Part 1: Specifications. It specifies the product classification, technical requirements and test methods, sampling, inspection rules and standards of acrylonitrile for industrial use. signs, labels and accompanying documents, packaging, transport and storage.

--- Part 5: Determination of acidity, pH value and titration value. Determination of acidity by chemical titration; pH measurement by pH meter; Potentiometric drop Determine the titer value.

--- Part 8: Determination of total aldehyde content Spectrophotometric method. It is the reaction of total aldehydes and derivatizing reagents to produce colored anionic dyes.

The absorbance value was measured, and the total aldehyde content was calculated.

--- Part 9: Determination of total cyanide content by titration. The cyanide in the sample is extracted with an alkaline solution of potassium iodide to make it soluble The total cyanide content was calculated by titration with silver nitrate standard titration solution.

--- Part 10: Spectrophotometric method for the determination of peroxide content. Under the action of acetic anhydride, peroxide reacts with potassium iodide Yellow iodide ions should be generated, and the content of peroxide is calculated by measuring the absorbance value of the solution.

--- Part 11: Determination of iron and copper content by spectrophotometry. Evaporate the sample to dryness and digest with mixed acid to remove organic matter, and iron After the ion and copper ions react with the derivatizing reagent respectively, a colored complex is formed, which is measured with a spectrophotometer, and the iron and copper are calculated. content.

--- Part 12: Determination of purity and impurity content by gas chromatography. is the determination of the purity of acrylonitrile samples by gas chromatography and impurity content.

--- Part 15: Determination of p-hydroxyanisole content. Including spectrophotometry and gas chromatography. where spectrophotometry uses The absorbance of the sample was directly measured at 295 nm by an ultraviolet spectrophotometer, and the content of p-hydroxyanisole was calculated; gas chromatography method The content of p-hydroxyanisole was separated and determined by gas chromatography.

--- Part 16: Determination of iron and copper content by graphite furnace atomic absorption spectrometry and inductively coupled plasma mass spectrometry. of which stone Ink furnace atomic absorption spectrometry is to measure the absorbance at the characteristic wavelengths of iron and copper after diluting the sample with ethanol.

Calculate the iron and copper content; inductively coupled plasma mass spectrometry is to dilute the sample with ethanol, add the internal standard solution, and use iron and copper.

The characteristic mass of the mass spectrometer was collected, and the iron and copper contents were calculated.

Industrial Acrylonitrile Part 12: Determination of purity and impurity content gas chromatography Caution - This document is not intended to address all safety issues related to its use. It is the user's responsibility to take appropriate safety and Health measures to ensure compliance with the relevant state regulations.

1 Scope

This document specifies a gas chromatographic method for the determination of the purity and impurity content of acrylonitrile for industrial use. These impurities include acetaldehyde, acetone, propylene Aldehyde, benzene, methacrylonitrile, acetonitrile, azole, propionitrile, cis-butenenitrile and trans-butenenitrile, etc.

This document is applicable to the determination of acrylonitrile samples with a purity of not less than 99% (mass fraction), of which condition 1 in Table 1 is suitable for the content of not less than 99% (mass fraction).

For the determination of impurities at 10.0 mg/kg and the purity of acrylonitrile, Condition 2 applies to impurities with a content of 2.0 mg/kg to 10.0 mg/kg (A other than acrylonitrile).

2 Normative references

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

GB/T 3723 General Rules for Sampling Safety of Chemical Products for Industrial Use

GB/T 6283 Determination of moisture content in chemical products Karl Fischer method (general method)

GB/T 6324.8 Test methods for organic chemical products - Part 8: Determination of moisture in liquid products - Karl Fischer Coulomb coulometric method

GB/T 6680 General Rules for Sampling of Liquid Chemical Products

GB/T 7717.5 Industrial Acrylonitrile Part 5: Determination of Acidity, pH Value and Titration Value

GB/T 7717.15 Industrial Acrylonitrile Part 15: Determination of p-Hydroxyanisole content

GB/T 8170 Numerical Rounding Rules and Representation and Judgment of Limit Values

3 Terms and Definitions

There are no terms and definitions that need to be defined in this document.

4 Method summary