Mensuration of Natural Vitamin A in Fish Liver Using Liquid Chromatography

To mensurate the content of vitamin A (vitamin A1, vitamin A2) in fish liver accurately, methods of sample pretreatment (including water bath saponification, room temperature saponification, and direct extraction) and detection methods (including normal phase chromatography and reversed phase chromatography) were screened and applied to the mensuration of vitamin A in the liver of 9 economic fish species. The results revealed that by reversed phase chromatography vitamin A1 and vitamin A2 were effectively divided, and showed good linear relationship within their respective linear ranges (R2 > 0.99). The content of vitamin A extracted by water bath saponification was distinctly higher than the content of Vitamin A by room temperature saponification and direct extraction (p < 0.05). Its average recovery rates of vitamin A1 and vitamin A2 were respectively 104.52% and 90.94%. The total content of vitamin A in the livers of other freshwater fishes and marine fishes except for the freshwater snakehead and big mouth bass was more than 200 μg/100 g, and the total content of vitamin A in the liver of marine giant grouper is 14,413.78 μg/100 g, among the result was the highest. The water bath saponification method with reversed phase chromatography has good precision and is suitable for the mensuration of vitamin A in fish liver.