GB/T 14571.2-2018Test method of ethylene glycol for industrial use—Part 2: Determination of purity and impurities—Gas chromatography (English PDF)

Foreword

GB/T 14571 consists of the following parts.

GB/T 14571.1, Test method of ethylene glycol for industrial use - Part 1. Determination of acidity - Titration method

GB/T 14571.2, Test method of ethylene glycol for industrial use - Part 2. Determination of purity and impurities - Gas chromatography

GB/T 14571.3, Ethylene glycol for industrial use - Determination of content of total aldehydes present - Spectrophotometric method

GB/T 14571.4, Ethylene glycol for industrial use - Determination of ultraviolet transmittance - Ultraviolet spectrophotometric method

GB/T 14571.5, Test method of ethylene glycol for industrial use - Part 5. Determination of chloride ion - Ion chromatography

This Part is Part 2 of GB/T 14571.

This Part was drafted in accordance with the rules given in GB/T 1.1-2009. This Part replaces GB/T 14571.2-1993 "Ethylene glycol for industrial use. Determination of diethylene glycol and triethylene glycol. Gas chromatographic method".

Compared with GB/T 14571.2-1993, main changes in this Part are as follows.

- modified standard's name;

- modified tiles of related clauses (see Clause 3~Clause 11 of this Edition, Clause 3~Clause 9 of Edition 1993);

- modified scope (see Clause 1 of this Edition, Clause 1 of Edition 1993);

- added relevant standards to normative references (see Clause 2 of this Edition, Clause 2 of Edition 1993);

- modified principle (see Clause 3 of this Edition, Clause 3 of Edition 1993);

- deleted packing column; deleted capillary column type and chromatographic conditions (see Table 1 of this Edition, Table 1 of Edition 1993);

- added calculation of ethylene glycol purity (see Clause 8 of this Edition);

- added contents related to determinations of 1,2-propanediol, 1,2-butanediol, 1,4-butanediol, 1,2-hexanediol, ethylene carbonate, and 1,3-dioxane-2-methanol (see Clause 1, Clause 7 and 4.5.2 of this Edition);

- modified quantification method from external standard method and internal standard method to corrected area normalization method (see Clause 8 of this Edition, 7.3 and Annex A of Edition 1993);

- modified precision data of method (see Table 2 of this Edition, Table 2 of Edition 1993);

- added quality assurance and control (see Clause 10 of this Edition);

- deleted Annex A (See Annex A of Edition 1993).

1 Scope

This Part of GB/T 14571 specifies principle, reagents or materials, instruments and devices, samples, test procedures, test data processing, precision, quality assurance and control, test report of gas chromatography for determination of purity and impurities in ethylene glycol for industrial use.

This Part is applicable to determine the ethylene glycol sample for industrial use of which purity is not less than 98.0% (mass fraction). Where, the detection limit of 1,2-propanediol and triethylene glycol is 0.0020% (mass fraction). The detection limit of 1,3-dioxane-2-methanol, diethylene glycol, 1,2-butanediol, 1,4-butanediol, 1,2-hexanediol and ethylene carbonate is 0.0010% (mass fraction).

2 Normative references

The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

GB/T 3723, Sampling of chemical products for industrial use - Safety in sampling

GB/T 6678, General Principles for Sampling Chemical Products

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

3 Principle

Under specified conditions, inject an appropriate amount of sample into the chromatograph that is equipped with hydrogen flame ionization detector (FID).

4 Reagents or materials

WARNING - Gases in 4.1~4.4 are high-pressure compressed gas or pressurized flammable gas. Most of standard reagents in 4.5 are flammable or toxic liquids. Pay attention to safety in use.

4.5 Reagents.

5 Instruments and devices

5.1 Gas chromatograph. equipped with hydrogen flame ionization detector. The peak height of the lowest measured concentration of impurities specified in this Part shall be at least twice the noise. Dynamic linear range meets quantitative requirements.

5.3 Analytical balance. resolution is 0.1mg.

5.4 Sample introduction device. 10µL micro syringe or liquid autosampler.

5.5 Recording device. electronic integrator or chromatography workstation.

6 Sample

Perform sampling according to the provisions of GB/T 3723, GB/T 6678, GB/T 6680.

7 Test steps

8 Processing of test data

9 Precision

10 Quality assurance and control

10.1 The laboratory shall periodically analyze the quality control samples to ensure the accuracy of the test results.

10.2 The quality control sample shall be stable and representative of the sample being analyzed. The quality control sample can use the calibration solution that is self-prepared according to 7.2 or the certified standard solution sold at market.

11 Test report

The report shall contain the following information. […]