Rapid determination of lycopene and β-carotene in tomato by liquid chromatography electrospray tandem mass spectrometry

BACKGROUND: The tomato fruit is a dietary source of carotenoids, bioactive antioxidant compounds that play an important role in the prevention of degenerative diseases. Several extraction and detection techniques regarding carotenoids in tomatoes can be found in the literature, mainly based on high-performance liquid chromatography separation and ultraviolet-visible detection. RESULTS: The best extraction conditions and tandem mass spectrometry (MS) analysis were evaluated: lycopene and β- carotene were extracted in a cyclohexane/ethyl acetatemixture without the addition of antioxidants, next separated by liquid chromatography on a C18 column and then determined through electrospray tandem MS. Ionic suppression by the matrix in negative ionisation mode did not allow the analysis of extracts, hence the positive ionisation mode was chosen. Validation parameters demonstrated the suitability for purpose of the analytical method: accuracy, precision, linearity and detection limits were adequate. The method was finally applied to different tomato samples, and differences could be easily highlighted. CONCLUSION: The method was simple, fast and appropriate for the purpose of analysing lycopene and β-carotene in tomatoes.