Analysis of fat-soluble vitamins. XXV. High performance liquid chromatographic determination of vitamin D in multivitamin preparations: collaborative study
De Vries, E.J.; Mulder, F.J.; Borsje, B.
Journal - Association of Official Analytical Chemists 64(1): 61-70
1981
ISSN/ISBN: 0004-5756 PMID: 7204312 Document Number: 173318
The HPLC method for determining vitamin D in multivitamin preparations was studied collaboratively. Samples were distributed to 43 laboratories in 10 countries. Twenty-four laboratories gave their results. The method specifies a reverse phase system for the cleanup and a straight phase system for the determination. Difficulties arise when laboratories are equipped with HPLC apparatus with a single column. Laboratories experienced in vitamin D analysis reported good results, even if they were equipped with a single column HPLC apparatus. Eleven of the 24 laboratories reported satisfactory results. For this rather complicated method, the coefficient of variation for a single assay is acceptable. The method has been adopted official first action as an alternative procedure to the chemical method for determining vitamin D in multivitamins.