Quantification of 1α,25-Dihydroxy Vitamin D by Immunoextraction and Liquid Chromatography–Tandem Mass Spectrometry

Abstract

Protein precipitation with antibody-based extraction is effective for sample preparation before LC-MS/MS analysis of derivatized 1,25(OH)(2)D. This method appears to have improved specificity over a clinically used RIA with low imprecision and limits of detection.