Resolving 18 PAHs, Including Benzofluoranthenes, Using the Unique Selectivity of a 50% Phenyl Methylpolysiloxane- Phased GC Column

　　Abstract

　　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 Thermo Scientific™ 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.

　　Introduction

　　The GC column most commonly used for PAH analysis is a low polarity 5% diphenyl/95% dimethyl polysiloxane (equiv to 5SilMS) stationary phase. This can separate a 16 priority PAH standard mix according to US EPAMethod 610. However, when two EU PAHs, benzo[e] pyrene and benzo[j]fluoranthene are added to the mix, benzo[j]fluoranthene co-elutes with two other isobaric components benzofluoranthenes b and k. These three challenging isobaric compounds are difficult to resolve by GC-MS.

　　The stationary phase in the TraceGOLD TG-17SilMS GC column, unlike any other 50% phenyl methylpolysiloxane (17MS) phase, is optimized to give unique selectivity to separate isomeric pairs as well as isobaric PAHs using GC-MS. Thus, the column provides adequate resolution for these critical pairs.

　　The resolution of benzo[j]fluoranthenes from benzofluoranthenes b and k, and the separation of 18 PAHs on a TraceGOLD TG-17SilMS GC column is demonstrated. This low bleed column offers more resolving power for the separation of critical pairs and isobaric compounds compared to a 5% diphenyl/95% dimethyl polysiloxane stationary phase GC column.