title: Nonaqueous reverse phase liquid chromatographic determination of vitamin D2 in multivitamin tablets, using vitamin D3 as internal standard.
abstract: The technique of nonaqueous reverse phase chromatography has been successfully applied to the separation of lipophilic vitamins D2 and D3. Separation is achieved with a Zorbax-ODS column and a mobile phase of 10% methanol in acetonitrile. A predetermined amount of vitamin D3 internal standard is added to a portion of a powered tablet sample, which is then extracted and partitioned with a mixture of dimethyl sulfoxide, water, methanol, and hexane. A portion of the hexane extract is concentrated, and purified by passing it through a disposable silica cartridge to remove interfering materials. The method should also be applicable to formulations containing vitamin D3 where vitamin D2 can then be used as the internal standard. A system suitability test is included in the method.
mesh_terms: D002762:Cholecalciferol / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004872:Ergocalciferols / Q000032:analysis* / Q000592:standards; D012015:Reference Standards; D013607:Tablets / Q000032:analysis
chemical_list: D004872:Ergocalciferols; D013607:Tablets; D002762:Cholecalciferol