The component of hydrocarbon mixture is very complicated, including even and odd number carbon hydrocarbon. Its analysis with conventional gas chromatographic approaches is a big challenge and can give us inaccurate or even false results because overlapping is always happened. Many measures were taken to avoid interferences, such as improving sample preparation or using high selectivity detectors. Multi-dimensional GC/GCMS system with multiple heart-cutting is one of the powerful tools. Multi-dimensional GC/GCMS can improve resolution beyond that of the regular GC analysis as it re-introduces the dissolved component of interest into another column. In other words, only part of the peak of the component that was insufficiently separated on the column where the sample initially passed through (called the "1st column") is introduced (heart-cut) to a column of another type (called the "2nd column"), so that insufficiently separated components can be separated. A device called a "switching device" is used for heart-cut introduction of peaks eluted from the 1st column to the 2nd column. As a switching device, the recently developed Multi-Deans switching unit can be used in combination with a GC-FID as the first analytical dimension and a GCMS as the second analytical dimension. The analytes pass the first column and are detected in the FID ("stand-by mode") or are transferred to the second column and analyzed with mass spectrometer or GC detector such as FID ("cut mode"). By using this system, complicated matrix analysis such as hydrocarbon mixture was done to demonstrate MDGC/GCMS system performance.
This MDGC/GCMS system can analyze the olefine and aromatic hydrocarbon in hydrocarbon mixture. It has superiority on the determination of the complicated matrix sample in order to obtain more reliable analytical results.