| Abstract: | Abstract An isomeric pair of compounds is obtained from 4-car-boxyaldehydephenanthrene-5-carboxylic acid (1) by various methods routinely applied for the methylation of acidic oxygenation products of K-region polycyclic aromatic hydrocarbons (PAH's) prior to GC and GC/MS analysis. Differentiation of the individual cyclic and acyclic isomers, a classical general problem, proves possible by careful analysis of the mass spectral fragmentation patterns in the representative case studied here. |
