气相色谱-飞行时间质谱分析焦化柴油中氮化物组成

采用固相萃取法分离富集焦化柴油中的含氮化合物组分,然后通过气相色谱/场电离-飞行时间质谱(GC/FITOFMS)及气相色谱/四级杆-飞行时间质谱(GC/QTOFMS)对含氮化合物类型进行定性分析.结果表明,焦化柴油中除了常见的苯胺类、吲哚类、喹啉类、苯并喹啉类、咔唑类、苯并咔唑类氮化物外,还发现了四氢异喹啉类、苯基吡啶...

Analysis of Nitrogen Compounds in Coker Diesel by Gas Chromatography Time-of-Flight Mass Spectrometry

Solid phase extraction was applied to separate nitrogen compounds in coker diesel. Then, composition of nitrogen compounds was determined by both gas chromatography-field ionization-time-of-flight mass spectrometry (GC/FI TOF MS) and gas chromatography-quadrupole-time-of-flight mass spectrometry (GC/Q TOF MS). It was illustrated that there are nine kinds of nitrogen compounds in coker diesel including tetrahydroisoquinoline, phenyl-pyridines, phenyl-quinolines. Molecular structure of the newly found nitrogen compounds was further confirmed by GC/Q TOF MS. Response of different model compounds on GC/FI TOF MS was also investigated. It was found that the response factors of different nitrogen compounds are almost the same except aniline compounds; within a certain range of carbon numbers, response factors of homologs are equal with each other. GC/FI TOF MS was used to quantitatively analyze the nitrogen compounds in five different coker diesels. It was shown that carbon number of nitrogen compounds in coker diesels ranging from 8 to 23. Basic nitrogen compounds contents are between 54.8% to 59.5% and neutral compounds are about 40.5% to 45.2%. Carbon number distribution of the same nitrogen compounds in different coker diesels does not change. Aniline compounds carbon number shows a bimodal distribution, and γ carbon number distribution has been found for tetrahydroisoquinolines, quinolines and carbazoles.