| pubmed-article:2631567 | pubmed:abstractText | Chromatographic-spectrophotometric methods for the determination of vitamins K1, K3 and K4 in pharmaceuticals (tablets, dragees, injection solutions) in the presence of decomposition products have been elaborated. The TLC method on Kieselgel HF 254 (Merck) was applied to separation of the active substances from decomposition products, using the following solvent systems: benzene--ethyl acetate (9:1) for vitamin K1, cyclohexane--chloroform--metanol--acetic acid (2:15:3:1) for vitamin K3, and benzene--acetone (9:1) for vitamin K4. After elution from the plates, vitamin K1 was determined in ethanol at lambda = 251 nm, vitamin K3 in water at lambda = 234 nm and vitamin K4 in methanol at lambda = 225 nm. Maximum sensitivity of the elaborated methods came up to 7 X 10(-5) g, and standard deviations of single determinations ranged from 1.99% to 3.70%. | lld:pubmed |
