Polynuclear aromatic hydrocarbons (PAHs) are a severe environmental hazard with a variety of sources. Airborne particles, combustion products, and fossil fuels all contain these toxic aromatic substances. Analysis by gas chromatography (GC) has been problematic because GC phases do not meet the need for shape selectivity in separating PAHs. Conversely, high-density C18 octadecylsilane (ODS) phases for liquid chromatography (LC) have the proper bonded structure to allow this type of separation. The SUPELCOSIL LC-PAH column rapidly and economically separates PAH compounds.