A Highly Sensitive SPE Derivatization-UHPLC-MS Approach for Quantitative Profiling of Carotenoid-Derived Dialdehydes from Vegetables

Oxidative cleavage of carotenoids leads to dialdehydes (diapocarotenoids, DIALs) in addition to the widely known apocarotenoids. DIALs are biologically active compounds that presumably impact human health and play different roles in plant development and carotenoid metabolism. However, detection of DIALs in plants is challenging due to their instability, low abundance, and poor ionization efficiency in mass spectrometry. Here, we developed a solid-phase extraction and derivatization protocol coupled with ultrahigh performance liquid chromatography-mass spectrometry for quantitative profiling of DIALs. Our method significantly enhances the sensitivity of DIAL detection with a detection limit of 0.05 pg/mg of dried food materials, allowing unambiguous profiling of 30 endogenous DIALs with C-5 to C-24 from vegetables. Our work provides a new and efficient approach for determining the content of DIALs from various complex matrices, paving the way for uncovering the functions of DIALs in human health and plant growth and development.