Application of HPLC-APCI-MS with a C-30 reversed phase column for the characterization of carotenoid esters in mandarin essential oil

Liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (LC-APCI-MS) was used to identify carotenoid esters in mandarin essential oil. A gradient of methanol and methyl-t-butyl ether on a C-30 reversed-phase column was employed. The polymeric C-30 stationary phase has demonstrated superior resolution for carotenoid separation in comparison to the traditional C-18 column. Alkaline saponification is usually performed before carotenoid extract analysis by HPLC, thus no information concerning carotenoid esters in natural samples can be obtained. Because carotenoid esters are known to be more stable than free carotenoids, the main native carotenoid esters composition present in the non-volatile residue of mandarin essential oil was determined for the first time, thus providing a possible carotenoid esters profile characteristic for this oil. Moreover, good amounts of beta-cryptoxanthin and its esters were determined, indicating mandarin peel as a potential source of vitamin A precursors. Copyright (c) 2005 John Wiley & Sons, Ltd.