Highly sensitive and accurate profiling of carotenoids by supercritical fluid chromatography coupled with mass spectrometry

We attempted to establish a high-speed and high-resolution profiling method for a carotenoid mixture as a highly selective and highly sensitive detection method; the analysis was carried out by supercritical fluid chromatography (SFC) coupled with mass spectrometry (MS). When an octadecyl-bonded silica (ODS) particle-packed column was used for separation, seven carotenoids including structural isomers were successfully separated within 15 min. This result indicated not only improved separation but also improved throughput compared to the separation and throughput in RP-HPLC. The use of a monolithic ODS column resulted in additional improvement in both the resolution and the throughput; the analysis time was reduced to 4 min by increasing the flow rate. Furthermore, carotenoids in biological samples containing the complex matrices were separated effectively by using several monolithic columns whose back pressure was very low. The mass spectrometer allowed us to perform a more sensitive analysis than UV detection; the detection limit of each carotenoid was 50 pg or below. This is the first report of carotenoid analysis carried out by SFC-MS. The profiling method developed in this study will be a powerful tool for carrying out accurate profiling of biological samples.