Abstract
A recently proposed method for the separation of fat-soluble vitamins by electrokinetic chromatography was further developed and investigated in the present study. The separation medium consisted of acetonitrile-water (80:20 v/v) and contained 80 mM tetradecylammonium bromide (TDA+); the content of acetonitrile served to maintain the hydrophobic vitamins dissolved during electrophoresis, while the TDA+ ions served as the pseudostationary phase. With the cathode placed at the outlet of the capillary, the fat-soluble vitamins were separated based on different hydrophobic interactions to the TDA+ ions and migrated in order of decreasing hydrophobicity prior to the electroosmotic flow. Migration time stability was significantly enhanced by the addition of 4 mu borate to the separation medium. The separation system was validated for the determination of vitamin E acetate in commercial tablets; quantitative results deviated by less than 3.5% from specified values, varying by less than 2.5% relative standard deviation (RSD) for within-day experiments, and by less than 6.5% RSD during between-day experiments. The separation system was compatible with injection solvents ranging in polarity from water to tetrahydrofuran, and was even capable of separating the water-soluble vitamins B1, B2, B12, and nicotinamide.
| Original language | English |
|---|---|
| Journal | Electrophoresis |
| Volume | 19 |
| Issue number | 16-17 |
| Pages (from-to) | 2912-2917 |
| Number of pages | 6 |
| ISSN | 0173-0835 |
| Publication status | Published - 1 Nov 1998 |
Keywords
- Electrokinetic chromatography
- Fat-soluble vitamins
- Pharmaceutical products
- Tetradecylammonium bromide
- Water-soluble vitamins