title: Rapid automated high-performance liquid chromatographic assay for ercalcidiol and calcidiol (25-hydroxyvitamins D2 and D3) using trans-calcidiol as an ultraviolet-absorbing internal standard.
abstract: A system is described using high-performance liquid chromatography to separate and quantify, by spectrophotometry in a simple one-stage procedure, ercalcidiol (25-hydroxyvitamin D2) and calcidiol (25-hydroxyvitamin D3). The novel feature of the method is the employment of an ultraviolet-absorbing internal standard to monitor recovery. This has the advantage of permitting total automation of the quantification by eliminating the need for radioactivity counting. The method gives results that compare well with those obtained in other systems and has particular application in clinical studies where rapid separate determination of ercalcidiol and calcidiol is required.
mesh_terms: D015652:25-Hydroxyvitamin D 2; D001322:Autoanalysis; D002112:Calcifediol / Q000032:analysis* / Q000097:blood; D002851:Chromatography, High Pressure Liquid; D004872:Ergocalciferols / Q000031:analogs & derivatives* / Q000032:analysis / Q000097:blood; D006801:Humans; D012015:Reference Standards; D012997:Solvents; D013056:Spectrophotometry, Ultraviolet
chemical_list: D004872:Ergocalciferols; D012997:Solvents; D015652:25-Hydroxyvitamin D 2; D002112:Calcifediol