Maximising recovery using the Phenomenex Phree phospholipid removal plate to quantify 25-OH Vitamin D2 and D3 using an established LC-MS/MS method

Vitamin D requests in the clinical laboratory continue to increase owing to the publication of the National Osteoporosis Guidelines.1 Methods for the measurement of 25-OH vitamin D are still dominated by immunoassay in the clinical laboratory as they are simple and rapid. Liquid chromatography mass spectrometry (LC-MS/MS) is used in some laboratories as it provides superior analytical results and can identify 25-OH vitamin D2 and D3. This approach is not without problems and requires sample clean up prior to analysis. The aim of this study was to improve sensitivity in an established LC-MS/MS method for the quantification of 25-OH vitamin D2 (D2) and 25-OH vitamin D3 (D3).