Abstract:

This study aimed to establish a rapid method for the determination of lutein stereoisomers by high performance
liquid chromatography-diode array detection (HPLC-DAD) combined with atmospheric pressure chemical ionization mass
spectrometry (APCI-MS). Using a mobile phase composed of dichloromethane, acetonitrile and carbinol (20:30:50, V/V)
at a flow rate of 1.0 mL/min, lutein and its stereoisomers were separated effectively with good shape and without tailing
phenomenon. Lutein generated 15-, 13,13’- and 9,9’-mono-cis-lutein during thermal isomerization as identified based on the
maximum absorption wavelength, Q value, mass spectral characteristics and relevant literature data. Peak area and injection
amount of lutein showed a good linear relationship in the range of 4–260 ng. The recovery rate was higher than 95%, and
the relative standard deviations (RSDs) of both precision and stability were lower than 2%. The method has the advantage of
good separation, high accuracy and repeatability.

Key words: lutein, stereoisomers, measurement