Quantification of 3R,3′R-zeaxanthin in plant derived food by a diastereomeric dilution assay applying chiral high-performance liquid chromatography

For quantification of 3R,3′R-zeaxanthin in plant derived food, a new diastereomeric dilution assay (DIDA) was developed using chiral high-performance liquid chromatography coupled to diode-array detection (HPLC/DAD). As diastereomeric internal standard (I.S.), 3R,3′S-(meso)-zeaxanthin was applied. DIDA showed sufficient sensitivity with low limits of detection and quantification (18 μg 100 g−1 and 45 μg 100 g−1), a good inter-assay coefficient of variation (2.4%), determined by analysis of a certified BCR reference material, and a good recovery (94.7%). To prove the applicability of DIDA, various plant materials were anaylzed, showing that DIDA is highly advisable if saponification is applied during work-up to hydrolyze xanthophyll esters.