Detailed Hydrocarbon Analysis (DHA) of Gasoline

The purpose of detailed hydrocarbon analysis (DHA) is to determine the bulk hydrocarbon group type composition (PONA: Paraffins, Olefins, Naphthenes and Aromatics) of gasoline and other spark-ignition engine fuels that contain oxygenate blends (Methanol, ethanol, MTBE, ETBE, and TAME) according to ASTM D 6730. PONA analyte identification is conducted by matching retention indices with normal hydrocarbon paraffins. However, chromatograms obtained in PONA analyses have an extremely large number of peaks and their analytes may be mislabeled. Without accurate and reproducible retention indices, this may result in erroneous PONA ratios. The GC-2010 Plus incorporates an Advanced Flow Controller that enables highly precise flow control, and makes it easy to analyze and identify detailed hydrocarbons.

Example of a DHA analysis chromatogram

System GC

Conventional gas chromatographs require skilled operators to ensure precise analysis. By utilizing valve actuation to switch flow lines, system GCs provide key advantages over conventional systems for operators, such as automatic sampling, more precise analysis, and analytical time savings.