This analytical procedure specifies a reverse phase high performance liquid chromatographic with UV detection (RP-HPLC-UV) method for the simultaneous determination of four authorized carotenoids in fish compound feed, namely astaxanthin (AXN), canthaxanthin (CXN), adonirubin (ADR) and astaxanthin dimethyldisuccinate (AXN DMDS), and of six authorized carotenoids in poultry feed, namely canthaxanthin (CXN); capsanthin (CSN), ethyl ester of beta-apo-8'-carotenoic acid (BACARE), citranaxanthin (CIXN), lutein (LUT) and zeaxanthin (ZEA) at levels ranging from ca. 2 to ca. 4 500 mg/kg (depending on the carotenoid). Beta-carotene (BCAR), authorized in compound feed for all animal species, was also added to the scope. The analytical procedure is fit for the purpose of quantitation of declared carotenoids and labelling confirmation. The procedure applies to natural and synthetic feed additives.
Xanthophyll esters like those of lutein, zeaxanthin and capsanthin that might be present in feed materials are not authorized feed additives and therefore not part of the scope of this method.