Abstract: A gas chromatography quadrupole time-of-flight mass spectrometry method was developed for the qualitative and quantitative measurement of carbazole compounds in deeply hydrogenated diesel. This method could be used for qualitative analysis of five carbazole compounds with mass fraction in ng/g level，the linear correlation coefficient of the quantitative standard curve was above 0.998 0, and the recovery range was 81.86%-89.27%. The relative standard deviation range was 2.36%-4.14%，showing that the quantitative accuracy of the method was good. The minimum detection limits were 0.000 4-0.001 6 mg/L and the quantitation limits were 0.001 2-0.005 4 mg/L，illustrating that the sensitivity of the method was high. The carbazole compounds in hydrogenated diesel with different hydrofining depths were analyzed by this method. The results showed that carbazole and methyl carbazole was easily removed in the hydrofining process, and the 1- or 8-methyl-substituted dimethylcarbazole and trimethylcarbazole compounds had large steric hindrance and were difficult to be removed by hydrogenation.

Key words: gas chromatography quadrupole time-of-flight mass spectrometry, carbazole compounds, diesel, hydrogenation