scholarly journals Accurate and reliable quantification of 25-hydroxy-vitamin D species by liquid chromatography high-resolution tandem mass spectrometry

2015 ◽  
Vol 56 (6) ◽  
pp. 1234-1239 ◽  
Author(s):  
Gerhard Liebisch ◽  
Silke Matysik
Keyword(s):  
Mass Spectrometry ◽  
Vitamin D ◽  
Liquid Chromatography ◽  
High Resolution ◽  
Tandem Mass Spectrometry ◽  
Tandem Mass ◽  
25 Hydroxy Vitamin D ◽  
Reliable Quantification

scholarly journals State-of-the-Art Vitamin D Assays: A Comparison of Automated Immunoassays with Liquid Chromatography–Tandem Mass Spectrometry Methods

2012 ◽  
Vol 58 (3) ◽  
pp. 531-542 ◽  
Author(s):  
Christopher-John L Farrell ◽  
Steven Martin ◽  
Brett McWhinney ◽  
Isabella Straub ◽  
Paul Williams ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Vitamin D ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Tandem Mass ◽  
Concordance Correlation ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass ◽  
25 Hydroxy Vitamin D ◽  
Minimum Performance

Abstract BACKGROUND Vitamin D testing is increasing worldwide. Recently several diagnostic manufacturers including Abbott and Siemens have launched automated 25-hydroxy vitamin D (25OH-D) immunoassays. Furthermore, preexisting assays from DiaSorin and Roche have recently been modified. We compared the performance of 5 automated immunoassays, an RIA and 2 liquid chromatography–tandem mass spectrometry (LC-MS/MS) methods. METHODS Aliquots of 170 randomly selected patient samples were prepared and 25OH-D was measured by 2 LC-MS/MS methods, an RIA (DiaSorin), and automated immunoassays from Abbott (Architect), DiaSorin (LIAISON), IDS (ISYS), Roche (E170, monoclonal 25OH-D3 assay), and Siemens (Centaur). Within-run and between-run imprecision were evaluated by measurement of 5 replicates of 2 serum pools on 5 consecutive days. RESULTS The LC-MS/MS methods agreed, with a concordance correlation coefficient (CCC) of 0.99 and bias of 0.56 μg/L (1.4 nmol/L). The RIA assay showed a performance comparable to LC-MS/MS, with a CCC of 0.97 and a mean bias of 1.1 μg/L (2.7 nmo/L). All immunoassays measured total 25OH-D (including D3 and D2), with the exception of the Roche assay (D3 only). Among the immunoassays detecting total 25OH-D, the CCCs varied between 0.85 (Abbott) to 0.95 (LIAISON). The mean bias ranged between 0.2 μg/L (0.5 nmol/L) (LIAISON) and 4.56 μg/L (11.4 nmol/L) (Abbott). The Roche 25OH-D3 assay demonstrated small mean bias [−2.7 μg/L (−6.7 nmol/L)] [−2.7 μg/L (−6.7 nmol/L)] but a low CCC of just 0.66. Most assays demonstrated good intra- and interassay precision, with CV <10%. CONCLUSIONS Automated immunoassays demonstrated variable performance and not all tests met our minimum performance goals. It is important that laboratories be aware of the limitations of their assay.

Vitamin D analyses in veterinary feeds by gas chromatography-tandem mass spectrometry

2021 ◽  
pp. 146906672110002
Author(s):  
Andreas Lehner ◽  
Margaret Johnson ◽  
Alan Zimmerman ◽  
Justin Zyskowski ◽  
John Buchweitz
Keyword(s):  
Mass Spectrometry ◽  
Vitamin D ◽  
Gas Chromatography ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Vitamin D3 ◽  
Mass Spectrometric ◽  
Chromatographic Behavior ◽  
Tandem Mass ◽  
Chromatography Tandem Mass Spectrometry

This report examines the feasibility of determination of Vitamin D3, D2 and their 25-hydroxy metabolites utilizing Gas Chromatography Tandem Mass Spectrometry (GC/MS/MS) as a potential alternative to popular Liquid Chromatography Tandem Mass Spectrometric (LC/MS/MS) methodologies. The GC/MS/MS approach was found to operate reasonably well despite long-standing concerns that gas-liquid chromatography of vitamin D compounds invoke thermal rearrangements owing to the relatively high inlet and capillary column temperatures used. The workup procedure involved incubation of feed samples with concentrated potassium hydroxide for overnight fat saponification, extraction of D Vitamins in n-hexane and reaction with N,O-bis(trimethylsilyl)trifluoroacetamide at 70 °C for 30 mins. In addition to parent compounds, small amounts of pyro-, isopyro-, and iso-vitamin D and isotachysterol3 variants were obtained from each Vitamin D-related compound upon extraction and GC/MS/MS analysis. Mass spectral and chromatographic behavior of these compounds are herein described and interpreted. Multiple Reaction Monitoring settings on GC/MS/MS included m/z 456→351 for Vitamin D3 and m/z 486→363 for Vitamin D2. Trimethylsilylation enabled single predominant peaks for Vitamins D3 and D2, and sample workup in the presence of deuterated Vitamin D analogs enabled accurate and precise sensitivity to 1 ppb (ng/g) in feeds. The method could be extended with reasonable accuracy to 25-hydroxy (25OH) compounds, but accuracies would be significantly improved by inclusion of respective 25OH-specific deuterated internal standards. The method was applied to 27 submissions of suspect dog foods of which 22% were discovered elevated and 44% were discovered to contain toxic levels of Vitamin D3. The described method was thus discovered to provide a suitable mass spectrometric approach for Vitamin D, proving itself here specifically of value in detection of ergocalciferol and cholecalciferol in animal feeds. The specificity and sensitivity of the tandem quadrupole approach can enable suitable applicability to serum determination if desired.

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