<![CDATA[Along with the increasing transport of crude oils to the refinery sites, many accidentsof oil spills have been occurred in Indonesian waters. Such spills rnight be purely anaccident but some others are suspected to be deliberately spilled. Nevertheless, bothcases need an identification system to trace back the spill source and eventually the spilldata can be brought to the court as an evident. Previously, the identification system was conducted through a pattern recognition ofn-paraffin hydrocarbons of crude oil samples which are very distinguished from theirgas chromatographic (GC) pattern of n-CI7, Pristane, n-Cls, Phytane, and other n-paraffin’s down to n-C}0. Unfortunately, some crude oils have similar pattern that match-ing of two chromatograms could give an ambiguity result. Pattern recognition of isoprenoid hydrocarbons have been developed to character-i:ed crude oils that potentially pollute the Indonesian waters. Differing from the n-paraf-fin that each hydrocarbon peak can be determined definitely, the developed method doesnot need to identify each of the isoprenoid hydrocarbons, instead pattern of their chro-matographic separation are sufficiently distinguished. GC isoprenoid pattern recogni-tion is made from the isoprenoid peaks that ernerge between n-CI7 and n-Cls. It two crudeoils having similar pattern of n-paraffin ’s show very distinct pattern of iso-paraffin ’s.The method thus can be used as complimentary step in matching the GC pattern of crudeoil samples. Although in some cases GC isoprenoid peaks are not completely separated, this wouldnot be disadvantages since their retention tirne and area can be measured and integrateddefinitely, respectively. Nevertheless, the separation of iso-paraffin peaks can be easilyconducted using a recent GC method narnely a comprehensive two dimensional gas chro-matography (GCxGC), a method which is recommended to be implemented further in thisresearch.]]>
