聚间苯二甲酸丙二醇酯毛细管色谱柱的制备及在焦化酚检测中的分离性能和热稳定性

Preparation of Propanediol Isophthalate Polyester Capillary Chromatographic Column and Its Separation Performance and Thermal Stability in Coking Phenol Detection

以间苯二甲酸和1,2-丙二醇为原料进行酯化反应和聚合反应,制备聚间苯二甲酸丙二醇酯(聚酯),采用傅里叶变换红外光谱仪、核磁共振波谱仪以及质谱仪确定其微观结构。将聚酯填充于石英毛细管中制备毛细管色谱柱,并考察了自制毛细管色谱柱对工业焦化酚和高纯3,5-二甲酚中酚类同分异构体的分离性能。同时,采用容量因子曲线考察了自制毛细管色谱柱的热稳定性。结果显示:合成的聚酯的软化点为85℃,聚合度约为7。以自制毛细管色谱柱检测工业焦化酚时,除了2,4-二甲酚和2,5-二甲酚,苯酚、2,6-二甲酚、邻甲酚、间甲酚、对甲酚、对乙基酚、间乙基酚、3,5-二甲酚、3,4-二甲酚等9种组分的分离度均大于1.500,且3,5-二甲酚的理论塔板数达到2662个·m^(-1),9种组分峰面积的相对标准偏差(RSD,n=6)均小于6.0%;检测高纯3,5-二甲酚时,3,5-二甲酚的拖尾不影响附近杂质间乙基酚和3,4-二甲酚的分离,3,5-二甲酚与间乙基酚的平均分离度达到3.917,与3,4-二甲酚的平均分离度达到10.026,且3,5-二甲酚峰面积的RSD(n=6)小于1.0%;绘制自制毛细管色谱柱的容量因子曲线,最高使用温度达到225℃,在最高使用温度下连续使用7 d,容量因子未发生明显变化。

Propanediol isophthalate polyester(polyester)was prepared by esterification and polymerization reactions using isophthalic acid and 1,2-propanediol as raw materials,and its microstructure was determined using Fourier transform infrared spectrometer,nuclear magnetic resonance spectrometer,and mass spectrometer.Polyester mentioned above was filled into a quartz capillary tube to prepare a capillary chromatographic column,whose separation performance for phenolic isomers in industrial coking phenol and high-purity 3,5-xylenol was investigated. Meanwhile, thermal stability of the self-made capillary chromatographic column was evaluated using a capacity factor curve. It was shown that the softening point of the synthesized polyester was 85 ℃, and the polymerization degree was about 7. When using the self-made capillary chromatographic column to detect industrial coking phenol, except for 2,4-xylenol and 2,5-xylenol, the resolutions of 9 components including phenol, 2,6-xylenol, o-cresol, m-cresol, p-cresol, p-ethylphenol, m-ethylphenol, 3,5-xylenol, and 3,4-xylenol were greater than 1. 500, with RSDs (n=6) of the peak areas of the 9 components less than 6. 0%, and the theoretical plate numbers for 3,5-xylenol reached 2 662 m^(−1). When detecting high-purity 3,5-xylenol, the tailing of 3,5-xylenol did not affect the separation of nearby impurities such as m-ethylphenol and 3,4-xylenol, with the average resolution between 3,5-xylenol and m-ethylphenol of 3. 917, and the average resolution between 3,5-xylenol and 3,4-xylenol of 10. 026, and RSD (n=6) of the peak area of 3,5-xylenol was less than 1. 0%. The capacity factor curve of the self-made capillary chromatographic column was drawn, and the highest operating temperature reached 225 ℃. After continuous using for 7 d at the highest operating temperature, there was no significant change in the capacity factor.