title: Quantitation of 25-hydroxyvitamin D2 and D3 in serum and plasma by LCMS/MS.
abstract: OBJECTIVE
  We developed and validated an analytical method for quantifying 25-hydroxyvitamin D2 (25OHD2) and 25-hydroxyvitamin D3 (25OHD3) in serum and plasma.
  
  
  METHODS
  Samples, pretreated with zinc sulfate and methanol, were extracted with hexane. Separation was achieved via UHPLC and 25OHD quantification was accomplished by a triple quadrupole mass spectrometer.
  
  
  RESULTS
  Imprecision was 3.6-15.1%CV and bias 88.0-126.0%. Extraction efficiency was 76.5-110.5%, whereas the matrix effect ranged from -46.7 to -32.0%. The method was applied to authentic specimens. The results showed no significant difference between serum and plasma; strong correlation with paired values from an external laboratory; and analyte stability for 15 days.
  
  
  CONCLUSIONS
  This method provides reliable and accurate measurement of 25OHD for use in clinical practice.
authors.affiliation: UF Health Pathology Laboratories, Department of Pathology, Immunology & Laboratory Medicine, University of Florida College of Medicine, Gainesville, FL, USA.
authors.forename: Dayong
authors.initials: D
authors.lastname: Lee
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Garrett
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Goldberger
authors.forename: Lindsay A L
authors.initials: LA
authors.lastname: Bazydlo
mesh_terms: D015652:25-Hydroxyvitamin D 2 / Q000097:blood* / Q000592:standards; D000818:Animals; D001774:Blood Chemical Analysis / Q000379:methods*; D002112:Calcifediol / Q000097:blood* / Q000592:standards; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000592:standards; D006801:Humans; D011786:Quality Control; D012710:Serum Albumin, Bovine / Q000737:chemistry; D053719:Tandem Mass Spectrometry / Q000592:standards
chemical_list: D015652:25-Hydroxyvitamin D 2; D012710:Serum Albumin, Bovine; D002112:Calcifediol