... 25(OH )D .: 25-hydroxyl vitamin D 25(OH )D2 : 25-hydroxyl vitamin D2 25(OH )D3 : 25-hydroxyl vitamin D3 BHT : butylate hydroxytoluen BSTFA :N,O-bis(trimethylsilyl)trifluoroacetamide DM .: ... gm: vitamin D2 (ergocalciferol), vitamin D3 (cholecalciferol), v cỏc vitamin D4 , D5 , D6 , D7 Cu trỳc ca cỏc dng vitamin c trỡnh by hỡnh 1.1 i vi ngi cỏc hp cht quan trng nht nhúm vitamin D l vitamin ... ngoi ó c s dng phõn tớch nh lng ca vitamin D Trong cỏc pha rn, vitamin D2 cú th c phõn bit vi vitamin D da vo nh ph vitamin D2 ti 907 cm-1 [34] Ph FTIR c trng ca tinh th vitamin D2 v D3 cung a...