气相色谱法检测工业用乙二醇纯度及杂质

以Rtx-624色谱柱(30 m×0. 32 mm×1. 8μm)为分析柱进行分析,采用校正面积归一化法,建立了检测工业用乙二醇纯度及其中有机杂质的气相色谱分析法。该法可检测传统乙烯法制得的乙二醇中固有杂质二乙二醇、三乙二醇和1,3-二氧杂烷-2-甲醇,同时也适用于检测草酸酯加氢法制得的乙二醇中的新杂质(1,2-丁二醇、1,4-丁二醇、1,2-己二醇、碳酸乙烯酯等)。结果表明,该法具有良好的重复性和较高的检测灵敏度,检出限最低可达0. 000 2%(质量分数),回收率在91. 2%～105. 4%之间。该法在乙二醇生产控制、产品检测、市场贸易等过程中具有良好的应用前景。

Determination of purity and impurities of ethylene glycol for industrial use by gas chromatography

A new test method was established for the determination of purity and impurities of ethylene glycol (EG) by gas chromatography (GC) using a Rtx-624 column (30 m×0.32 mm×1.8 μm). The method determined not only the impurities in EG from the ethylene oxidation process, such as diethylene glycol, triethylene glycol and (1,3-dioxolan-2-yl)methanol, but also the impurities from the oxalate hydrogenation process, such as 1,2-butanediol, 1,4-butanediol, 1,2-hexanediol, and ethylene carbonate, etc. The method showed good repeatability and high detection sensitivity. The lowest LOD of the impurities reached to 0.0002% (mass fraction), and the recoveries of the impurities were in the range of 91.2%-105.4%. The proposed method can be applied in production control, product testing and market trade of ethylene glycol.