[Determination of nitrogen compounds in gasoline by gas chromatography-surface ionization detector]

Nitrogen compounds in gasoline were extracted by liquid-liquid extraction and analyzed by gas chromatography-surface ionization detector (GC-SID). Compared with the chromatograms obtained from GC-flame ionization detector (FID), GC-thermal ionization detector (NPD) and GC-mass spectrometry (MS), the peaks in the chromatogram obtained by GC-SID were assigned to the nitrogen compounds in gasoline. Most of these nitrogen compounds could not be detected by FID or NPD, which demonstrated the high selectivity and sensitivity of the SID. The types of nitrogen compounds in three gasoline samples (90#, 93#, 97#) were similar, but their contents varied with different gasoline brands. The extracted nitrogen compounds were mainly anilines, the amounts of which in the three gasoline samples were different. Trace amounts of several high boiling point nitrogen compounds were successfully detected because of the high sensitivity of SID. The SID is superior to the commercial NPD in detecting the nitrogen compounds in gasoline samples. In view of its high sensitivity and selectivity, the SID is a promising GC detector.