Determination of retinyl palmitate and total vitamin A content in liver and liver-based ready-to-eat foods.

The determination of retinyl palmitate and total vitamin A in liver and liver-based ready-to-eat foods is described. The method is very simple as sample preparation is minimal, and the isocratic elution of the C18 column with pure methanol does not necessitate a sophisticated instrumental set-up. The method is accurate with high recoveries (100.6 +/- 9.3%, mean +/- S.D., n = 23), and precise with within-day and between-day coefficients of variation of less than 5.5% (n = 13) and less than 16% (n = 6), respectively.