This method is for determining aromatics in petroleum distillates boiling in the range of 90 to 400°C by High Performance Liquid Chromatography (HPLC). The method determines aromatics from 0.001 to 4 mass. Above 4 mass, use IP Method 391. The aromatics should be predominantly mono-substituted, single-ring aromatics. Multiple-ring aromatic compounds and aromatic compounds containing two or more alkyl-substituents bias the results high. Significant levels of benzene bias the results low. Compounds containing sulfur, nitrogen, and oxygen may interfere. Mono-alkenes do not interfere, but conjugated di-alkenes and polyalkenes may interfere.