Analysis of monocyclic aromatic hydrocarbons by ASTM D7504 on the Agilent 8850 GC System

ASTM D7504 is a landmark method in the global chemicals industry for both quality control of finished products and process control of feed and intermediate streams. The key challenge of ASTM D7504 is the separation of the small ethylbenzene and m-xylene peaks from the large p-xylene peak in bulk p-xylene samples. Explore the analysis of monocyclic aromatic hydrocarbons by ASTM D7504 through two different approaches using the Agilent 8850 GC. The first approach follows a conventional application using helium carrier gas and a long column with a thick polyethylene glycol (or 'wax') phase and a total run time of 39 minutes. The second approach is a faster method that uses hydrogen carrier gas and a shorter and narrower wax column to yield a total run time of 6.05 minutes. The fast method maintains sufficient resolution of the ethylbenzene/p-xylene/m-xylene triplet without sacrificing method precision.