This gas chromatographic method is for determining trace amountsof p-diethylbenzene (p-DEB) or trace amounts of indan as impuritiesin C8 and lower boiling aromatic streams. The method can also beused for determining trace amounts of C8 aromatics in p-DEB, the C8aromatic isomers are resolved and determined individually. Highlevels of other C9 or C10 aromatics may interfere with thedetermination of trace p-DEB and indan in C8 aromatics. The lowerlimit of quantitation for each isomer is one mass- ppm.