In the present work two analytical methodologies in capillary electrophoresis (CE) were developed aiming the identification and quantification of thirteen nitrogen polycyclic aromatic compounds (NPAC) in diesel oil and gas oil samples. The two methodologies studied were micellar electrokinetic capillary chromatography (MECC) and microemulsion electrokinetic chromatography (MEEKC). The studied compounds were indole (I), 2-methylindole (2MI), 3-methylindole (3MI), 7-methylindole (7MI), quinoline (QNL), 7,8-benzoquinoline (78BQ), acridine (ACR), carbazole (CBZ), 3-ethylcarbazole (3EC), 9-methylcarbazole (9MC), 9-ethylcarbazole (9EC), N,N-dimethylaniline (A) e N-methylpirrole (P). The experimental conditions to both methods were adjusted aiming the separation of all analytes in a way to provide individual determination on samples. In MECC the background electrolyte was composed of boric acid, sodium dodecylsulphate (SDS), ureia e acetonitrile (ACN). Instrumental limits of quantification were from 1.0 to 7.8 mg L(-1). The fortified sample analysis produced recoveries values from 85 to 106 per cent. In MEEKC the background electrolyte was composed of ethyl acetate, butan-1-ol, SDS and sodium tetraborate. Instrumental limits of quantification were from 0.3 to 5.6 mg L(-1). The fortified sample analysis produced recoveries values from 89 to 103 per cent.