title: Tritium isotope effect in high-pressure liquid chromatography of vitamin D metabolites.
abstract: A significant chromatographic isotope effect is reported for 1,25-dihydroxyvitamin D3 in a wide variety of HPLC separation systems. The effect is also observed for 24,25-dihydroxyvitamin D3. Retention times differ from less than 1% up to 4% depending on the separation system and the degree and position of tritium substitution. Such an effect must be corrected for whenever both labeled and unlabeled vitamin D metabolites are used in HPLC cochromatography or assay recovery studies.
authors.affiliation: Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, Western Australia.
authors.forename: G K
authors.initials: GK
authors.lastname: Worth
authors.forename: R W
authors.initials: RW
authors.lastname: Retallack
mesh_terms: D015650:24,25-Dihydroxyvitamin D 3; D002117:Calcitriol / Q000032:analysis; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004100:Dihydroxycholecalciferols / Q000032:analysis; D012997:Solvents; D014316:Tritium; D014807:Vitamin D / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D004100:Dihydroxycholecalciferols; D012997:Solvents; D014316:Tritium; D014807:Vitamin D; D015650:24,25-Dihydroxyvitamin D 3; D002117:Calcitriol