Profiling of Citrus Oils and Determination of Furocoumarins in Citrus Oils

Introduction

Citrus oils are applied in numerous consumer products such as cosmetics and sun protection, food flavoring, and so forth. These oils contain significant amounts of psoralens, methoxylated flavonones, and flavones. A specific species of psoralens, namely furocoumarins, have been identified as photomutagenic and photocarcinogenic products. The analysis of such compounds in citrus oils can be done by (U)HPLC, however, chromatograms of such samples can be complex, and there is only limited certainty that a small peak for a target compound will be separated from other sample constituents. To increase the separation probability significantly, a radical increase in peak capacity is required. This can be accomplished by using comprehensive two-dimensional LC. A combination of normal-phase LC (NPLC) for the first dimension and reversed-phase LC (RPLC) for the second dimension resulted in good orthogonality.