气相色谱-质谱联用法分析全氟酰氟

摘要

采用气相色谱-质谱联用技术(GC/MS)对电化学氟化法生产的全氟环己烷酰氟产品中主要产物全氟酰氟进行了检测.在60℃下,采用甲醇对全氟环己烷酰氟产品进行甲酯化处理.考察了不同长度,极性及膜厚的毛细管色谱柱的分离效果.以KB-1MS毛细管色谱柱(90 m×0.25 mm×1.0 μm)为分离柱,采用GC/MS法对全氟酰氟组成进行了定性与定量分析；结合有机质谱学裂解规律,分别对环状全氟羧酸甲酯、饱和直链全氟羧酸甲酯和单不饱和脂肪酸甲酯的裂解方式和质谱特征进行了分析归纳.通过质谱数据库检索、标准品对照及已知全氟化合物的质谱信息分析,共鉴定出5种全氟酰氟,其中包括两种异构体；测得全氟环己烷酰氟约占总全氟酰氟含量的65％.%The perfluoro-carboxylic acid fluorides prepared by electrochemical penfluorination (ECPF) method were analyzed by gas chromatography/mass spectrometry.Methanol was used to convert the perfluorocarboxylic acid fluorides into the methyl esters at 60 ℃.The effects of column length,polarity and film thickness on the separation efficiency were investigated.The KB-1 MS capillary column (90 m × 0.25 mm ×1.0 μm) was employed in the GC/MS analysis.The fragmentation patterns and mass spectrometric characteristics of perfluorinated alicyclic acid methyl esters,aliphatic carboxylic acid methyl esters and monounsaturated perfluorinated aliphatic carboxylic acid methyl esters were analyzed and deduced from known patterns of perfluoro-organic mass spectrometry.In this work,five perfluoro-carboxylic acid fluorides including two isomers were identified and the perfluorocyclohexylcarboxylic acid fluoride accounted for about 65％ of the total perfluoro-carboxylic acid fluorides in the product.