Akademik Veri Yönetim Sistemi
CLINICAL LABORATORY, sa.6, ss.1017-1022, 2016 (SCI-Expanded)
Background: This study was designed to compare the performances of HPLC (High Performance Liquid Chromatography) and LC-MS/MS (Liquid Chromatography-Tandem Mass Spectrometry) methods in 25 (OH) D3 testing. Methods: This study is comprised of 306 randomly chosen plasma samples from the subjects who applied for routine measurement of 25 (OH) D-3. Plasma 25 (OH) D-3 levels were quantified using HPLC and LC-MS/MS. The LC-MS/MS method was used as the reference method. The linearity, precision, carry-over, limit of blank, limit of detection (LoD), and comparison studies were done for method validation. Accuracy was tested using external quality assurance samples. Results: Coefficients of variation for both methods were at around 10.0%. The HPLC and LC-MS/MS assays were linear over the working range from 5.0 to 100 ng/mL (r > 0.99). The HPLC assay showed a higher LoD compared to LC-MS/MS (5.1 vs. 1.6 ng/mL, respectively). Results from external quality assurance samples were within +/- 1 SD range for both methods. The comparison study revealed good correlation between HPLC and LC-MS/MS methods (y = 1.054x-1.981 with a small mean bias (-0.953) (r = 0.9752)), when all samples were included, regardless of their 25 (OH) D3 levels. However, the correlation was poor for samples with 25 (OH) D3 concentrations lower than 10 ng/mL. Conclusions: Both methods have acceptable performance characteristics for use in clinical diagnostic applications. A good comparability was obtained between HPLC and LC-MS/MS methods. However, LoD of HPLC assay was higher and there was a poor correlation between the two systems for samples with 25 (OH) D3 concentrations below 10 ng/mL, showing that LC-MS/MS system is more successful in measuring samples with low 25 (OH) D3 concentration.