Heavy Fuel Oil (also "bunker oil" or "residual fuel oil") is a complex mixture of petroleum hydrocarbons formed as the remnant of distillation and cracking processes. Often used by the shipping industry, heavy fuel oils have becoming more regulated for lower sulfur content.
Comprehensive two-dimensional gas chromatography paired with high-resolution time-of-flight mass spectrometry and multiple ionization modes can provide a full characterization of the volatile and semi-volatile compounds in this complex mixture.