Analysis of contact allergenic compounds in oxidizedd-limonene

Summary

A detailed chemical analysis and quantification of oxygen-containing monoterpenes in auto-oxidizedd-limonene was performed. Some of these, e.g. the cis- and trans-isomers of limonene-2-hydroperoxide, have previously been shown to exhibit strong contact allergenic properties. GC-MS with chemical ionization in negative ion mode was shown to be a successful method for the identification and determination of the molecular weight of chemically unstable limonene hydroperoxides. An HPLC method for isolation of individual compounds in auto-oxidizedd-limonene is presented. Two different stationary phases were used in normal phase mode, cyanopropyl- and diamino-modified silica. The method described can be used for the isolation of individual contact allergens in sensitization experiment vehicles, such as petrolatum and olive oil. This makes it possible to study whether test compounds, such as hydroperoxides, are chemically stable during a sensitization experiment.