Analysis of hepatic vitamins A_1, A_2, their fatty acyl esters, and vitamin E for biomonitoring mammals feeding on freshwater fish

摘要

In tissues of freshwater fish-feeding mammals, 3,4-didehydroretinol(A_2) is a major from of vitamin A. In mink liver, with organochlorine exposure, this analog has been found to decrease more than retinol(A_1) and thus has potential as a sensitive freshwater biomarker. the presence of the analogs A_1 and A_2 as alcohol and different fatty acyl esters, which react to polychlorinated biphenyls differently, necessitates detailed analyses achieved by using direct extraction of tissue homogenate. In direct hexane extraction, compared to total levels of the vitamins obtained in the saponsification procedure, a large proportion of the vitamins was released only after repeated and long-time vortex mixing with the extraction solvent.