cold-pressed citrus essential oils contain variable amounts of oxygen heterocyclic compounds highly characteristic of each species. their distribution has been defined by high-performance liquid chromatography (hplc) analysis with an average time of about 45 minutes. here are two methods proposed, applying the latest generation hplc columns based on the fused-core technology. the first method allows the complete resolution of thirty-eight components for a rugged and validated quantitative determination of the oxygen heterocyclic compounds in cold pressed lemon, lime, bergamot grapefruit, sweet orange, bitter orange and mandarin oils, in 10 minutes of total analysis time. the second method is a compromise between chromatographic resolution and analysis time and allows a fingerprinting of each of the abovementioned oils to be obtained, useful for unveiling possible contaminations and frauds in about 3 minutes. this last method can be applied in routine analysis to save time and solvent. the components are sufficiently separated in all the citrus cold pressed oils, permitting detailed profiles of each oil to be acquired and possible contaminations and frauds to be detected.