乙二醇单甲醚合成液的气相色谱分析

Gas Chromatogram Analytical of Ethylene GlycolMonomethyl Ether Synthesis Liquid

用气相色谱法对乙二醇单甲醚合成液进行跟踪分析。采用φ3 mm×1 m[m(改性PEG20M)︰m(酸洗硅烷化201担体)=10︰100]不锈钢柱;升温程序:60℃(2 min)6℃/min 160℃(20 min),H2=50 mL/min,N2=50 mL/min,AIR=400 mL/min;汽化室温度250℃,检测室温度250℃。建立了一种简便,快速,准确的乙二醇单甲醚合成液中各组分的测定方法。该方法各主产物与原料能达到基线分离,难分离物质对达到峰谷分离。多次测定结果的相对误差是0.27%,相对标准偏差是0.82%(以乙二醇单甲醚计),分析时间小于30 min,适合于生产中的控制分析。

Polysaccharides were extracted from orange skin by alcohol precipitating-water extracting method. Three factors influencing extraction performances, such as extraction temperature, extraction time and ratio of material to water were investigated through orthogonal experiment design. The optimum extraction conditions were determined：the ratio of material to water 1 ： 35, extraction temperature 90℃, and the extraction time 120 min. Phe- nol-sulfuric acid method was employed to determine polysaccharides content in orange skin. The results show that the conversion factor of polysaccharides in orange skin is 3.15, the average mass fraction is 2.36%, and the relative standard deviation （RSD） is 2.14%.