This gas chromatographic method is for determining individual and composite trace non-aromatic hydro-carbon impurities in olefin-free aromatic mixtures. C8 and lower boiling paraffins and naphthenes are de-termined individually and then summed by carbon number and carbon type. C9 non-aromatics are reported as a composite. The method is not quantitative for C3 and lower molecular weight hydrocarbons due to their volatility. The range of quantitation for each component is 1 to 2000 mass-ppm. The range of quanti-tation for each composite depends upon the number of components in the composite.
An alternative method providing similar information is UOP Method 868, Trace Saturates in High Purity Aromatics by GC. It uses a two-column system to report paraffins and naphthenes by carbon number through C10.