溶剂型聚氨酯防水涂料挥发性有机化合物含量气相色谱检测方法探讨

Discussion on Gas Chromatography Detection Method for Volatile Organic Compound Content in Solvent Polyurethane Waterproofing Coating

采用气相色谱法对溶剂型聚氨酯防水涂料进行挥发性有机化合物含量测试,研究甲苯和二乙二醇二甲醚两种内标物对检测结果的影响。结果表明:二乙二醇二甲醚作为内标物,其挥发性有机化合物含量的测试结果是甲苯作为内标物的近3倍。溶剂型聚氨酯防水涂料的挥发性有机化合物主要为三甲苯和四甲苯的混合物,因难以获得其校准物质,故按相关标准规定其相对校正因子均设为1.0,甲苯与二乙二醇二甲醚两者分子结构相差较大,导致测试结果差异也较大,选择与三甲苯、四甲苯分子结构相近的甲苯作为内标物较为合理。

Gas chromatography is used to test the volatile organic compound content of solvent polyurethane waterproofing coatings,and the influence of two internal standard substances,i.e.toluene and diethylene glycol dimethyl ether,on the testing results is studied.The results show that the volatile organic compound content of the coating which takes diethylene glycol dimethyl ether as an internal standard is nearly three times higher than that of the coating with toluene as an internal standard.The volatile organic compound of solvent polyurethane waterproofing coating is mainly a mixture of trimethylbenzene and tetramethylbenzene.Due to the difficulty in obtaining their calibration substances,their relative correction factors are set to 1.0 according to relevant standards.The molecular structures of toluene and diethylene glycol dimethyl ether differ greatly,resulting in significant differences in test results.Therefore,it is more reasonable to choose toluene,which has a similar molecular structure to trimethylbenzene and tetramethylbenzene,as the internal standard.