Abstract
Accurate quantification of fat-soluble vitamin A （VA）， vitamin D （25（OH）D）， vitamin E （VE）， vitamin K （VK） is essential for health assessment and disease diagnosis. Liquid chromatography-tandem mass spectrometry （LC-MS/MS） plays a crucial role in the measurement of these vitamins due to its high specificity and sensitivity. However， the comparability and concordance of the detection results among different LC-MS/MS methods are still suboptimal. In this study， the analytical performance including linearity， limit of detection， limit of quantitation， precision， accuracy and carryover was evaluated according to CLSI C62 and the Suggestions on Clinical Application of Liquid Chromatography-Mass Spectrometry. Aliquots of 40 patient samples were collected from August to October 2022 from the Second Xiangya Hospital， Central South University. These fat-soluble vitamins were measured using three LC-MS/MS methods. Passing-Bablok regression， Bland-Altman plots and concordance correlation coefficient （CCC） were performed to compare the differences among three methods. The consistency of the results before and after recalibration with a unified calibrator was evaluated. The results showed that the total CVs for the three mass spectrometry kits were 2.7%-10.1%， and the recoveries for all kits ranged from 88.8% to 109.2%， indicating that their detection performance met the requirements for clinical application. Concordance correlation analysis showed that two of the three methods had substantial agreement in vitamin D testing （CCC： 0.938）， while the CCCs for other methods ranged from 0.322 to 0.853. After recalibration with a unified calibrator， except for vitamin K， the CCCs for the results of the three methods ranged from 0.918 to 0.983. In conclusion， the performance validation results of three LC-MS/MS methods for fat-soluble vitamins meet clinical requirements. The consistency among the three methods was poor， but using a unified calibrator significantly improved the consistency of these methods. The study provides recommendations for the standardization of clinical fat-soluble vitamin testing， thereby contributing to improved accuracy and consistency of results. This study will provide more reliable evidence for clinical diagnosis and treatment.