GB/T 14571.2-2018 in English

Standard formulation background and technology evolution analysis

Background introduction:

With the continuous expansion of the application field of industrial ethylene glycol, the requirements for product quality are increasing. The old version of the standard only focuses on the determination of some specific impurities, while the new version of the standard comprehensively improves the accuracy and applicability of purity and impurity analysis by introducing gas chromatography.

Technological evolution:

• From single impurity detection to comprehensive impurity spectrum analysis
• From simple separation to efficient chromatographic condition optimization
• From empirical quantification to standardized data processing methods

Instruments and operating specifications

Key instruments:

Gas chromatograph equipped with a hydrogen flame ionization detector (FID). It is recommended to use a 6%-cyanopropylphenyl-94%-dimethylpolysiloxane stationary phase column.

Operation points:

• Carrier gas flow control: 0.7~1.0 mL/min (N2)
• Column temperature program: initial temperature 80℃, heating rate 5-15℃/min, final temperature 230℃
• Detector temperature: 300℃

Implementation suggestions

Laboratory conditions:

• Ensure the stability and accuracy of the chromatographic system
• Calibrate the instrument regularly to ensure detection sensitivity and accuracy
• Equip standard solutions and reference samples

Data processing:

• Use the corrected area normalization method to calculate the impurity content
• Strictly perform numerical rounding in accordance with GB/T 8170
• Retain two decimal places (purity) and four decimal places (impurities)