Interlaboratory Comparison for the Determination of 24, 25-Dihydroxyvitamin D3 in Human Serum Using Liquid Chromatography with Tandem Mass Spectrometry. (22nd November 2019)

• Record Type: Journal Article
• Authors: Wise, Stephen A; Tai, Susan S-C; Nelson, Michael A; Burdette, Carolyn Q; Camara, Johanna E; Hoofnagle, Andrew N; Laha, Thomas J; Carter, Graham D; Jones, Julia; Williams, Emma L; Barclay, Zoe J; Jones, Glenville; Kaufmann, Martin; Binkley, Neil; Kapoor, Amita; Ziegler, Toni; Cashman, Kevin D; Dowling, Kirsten G; Sempos, Christopher T
• Is Part Of: Journal of AOAC International. Volume 100:Number 5(2017)
• Page Start: 1308
• Page End: 1317
• Publication Date: 2019-11-22
• Subjects: Agricultural chemistry -- Periodicals; Food -- Analysis -- Periodicals; 543
• DOI: 10.5740/jaoacint.17-0183
• Languages: English
• ISSNs: 1060-3271

Abstract

Abstract: Six laboratories associated with the Vitamin D Standardization Program (VDSP) participated in an interlaboratory comparison of LC with tandem MS (MS/MS) methods for the determination of 24, 25-dihydroxyvitamin D3 [24, 25(OH)2 D3 ] in human serum. The laboratories analyzed two different serum-based Standard Reference Materials (SRMs) intended for use in the determination of 25-hydroxyvitamin D and 30 samples from the Vitamin D External Quality Assessment Scheme (DEQAS). All laboratorymethods for 24, 25(OH)2 D3 were based on isotope dilution LC-MS/MS; three of the methods used derivatization of the vitamin D metabolites before LC-MS/MS. Laboratory results were compared to the National Institute of Standards and Technology (NIST) results, which were obtained using their newly developed candidate reference measurement procedure for 24, 25(OH)2 D3 . Laboratory results for the SRM samples varied in comparability to the NIST results, with one laboratory in excellent agreement (−1.6% mean bias), three laboratories at 10–15% mean bias, and the remaining laboratory at 36% mean bias. For the 30 DEQAS samples, the mean bias for the five laboratories ranged from 6 to 15%; however, the SD of the bias ranged from 8 to 29%. As a result of this intercomparison study, one laboratory discovered and corrected a methodcalculation error and another laboratory modified and improved their LC-MS/MS method.