AN 20740. One of the major difficulties in analyzing polycyclic aromatic hydrocarbons (PAHs) by GC-MS is achieving baseline resolution for isobaric compounds. In demonstrating the separation of 18 PAHs using a TraceGOLD™ TG-17SilMS GC column, the unique selectivity of this stationary phase is shown to fully resolve benzo[j]fluoranthene from benzo[b] fluoranthene and benzo[k]fluoranthene.