Retention Behavior of Large Polycyclic Aromatic Hydrocarbons in Reversed-Phase Liquid Chromatography

The analysis of materials for poly cyclic aromatic hydrocarbons (PAHs) is of great importance because of increasing concern over the mutagenicity and carcinogenicity of several of these compounds. The level of the biological activity, mutagenicity, or carcinogenicity, of a particular PAH is very dependent on structure, so that similar isomers can range from being highly active to being totally inactive [ 1 ]. Quantitation of the PAHs and their present levels in various materials could be used to estimate their bioactivity. Many analytical techniques have been used for PAH analysis, but many of the more common ones suffer from limitations when applied to larger PAHs (those of more than six rings). Most PAHs are not volatile and are therefore not easily amenable to analysis by gas chromatography (GC). The large number of isomers for any particular carbon number limits the use of mass spectrometry (MS) because of the identical molecular weights and similar fragmentation patterns that isomers yield. Reversed-phase liquid chromatography (RPLC) has therefore become one of the preferred methods for the separation and analysis of PAHs.