气相色谱法检测工业用乙二醇纯度及杂质

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

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。

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×1.8μm).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 0.000 2%(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.