CONTENTS OF CHOLECALCIFEROL, ERGOCALCIFEROL, AND THEIR 25-HYDROXYLATED METABOLITES IN MILK-PRODUCTS AND RAW MEAT AND LIVER AS DETERMINED BYHPLC

The cholecalciferol, ergocalciferol, 25-hydroxycholecalciferol, and 25 -hydroxyergocalciferol contents of seven raw meat items and five milk products were analyzed by a high-performance liquid chromatographic (H PLC) method. This included saponification, extraction, purification us ing one or two semipreparative HPLC steps, and quantification by HPLC. The quantification of cholecalciferol and 25-hydroxycholecalciferol w as based on the internal standard (IS) method. Ergocalciferol was used as an IS for cholecalciferol and 25-hydroxyergocalciferol as an IS fo r 25-hydroxycholecalciferol. The ergocalciferol and 25-hydroxyergocalc iferol contents were analyzed using an external standard method. The c ontents of the vitamin D compounds determined were low; the predominan t compounds were cholecalciferol and 25-hydroxycholecalciferol. The ch olecalciferol contents ranged in meat samples from <0.05 to 0.48 mu g/ 100 g and in milk product samples from <0.02 to 0.21 mu g/ 100 g. The 25-hydroxycholecalciferol contents were found to be <0.05-0.48 and not deteded-0.11 mu g/100 g in meat and milk product samples, respectivel y. Ergocalciferol and 25-hydroxyergocalciferol were not detected or th e contents were below or near the limit of determination (0.02-0.05 mu g/100 g of fresh weight).