The determination of lycopene Z‐isomer absorption coefficient on C30‐HPLC

Abstract

Abstract Both E‐ and Z‐isomers of lycopene are encountered in nature. Although they were separated on C30‐HPLC by the mobile phase consisting of CH3CN‐MeOH (A) and MTBE (B), the quantification of Z‐isomers cannot be archived at present because either their commercially available reference samples are currently lacking, or they are unstable. In this study, both the specific and molar absorption coefficients of 5, 9, and 13 Z‐isomers in the mobile phase were determined on the analytical C30‐HPLC‐PDA‐ELSD, and further verified on the preparative C30‐HPLC‐PDA. The specific and molar absorption coefficients of 5, 9, and 13 Z‐isomers were finally verified to be A1cm1% = 3,422 and εmol = 183,717, A1cm1% = 2,183 and εmol = 117,199, and A1cm1% = 1,119 and εmol = 60,076, respectively, in the mobile phase. With these determined coefficients, the quantifications of 5, 9, and 13 Z‐isomers were able to be archived on C30‐HPLC‐PDA with the mobile phase applied in this investigation.

Keywords

• all E‐isomer
• evaporative light scattering detector
• lycopene
• specific absorption coefficient
• Z‐isomer