|
KMID : 1100820120020040188
|
|
Laboratory Medicine Online
2012 Volume.2 No. 4 p.188 ~ p.196
|
|
|
Measurement of Serum Levels of 25-Hydroxyvitamin D3 and 25-Hydroxyvitamin D2 Using Diels-Alder Derivatization and Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry
|
|
Kim Hyung-Suk
Chun Sun-Hee
Kim Taek-Soo
Song Sang-Hoon
Park Kyoung-Un
Song Jung-Han
|
|
|
Abstract
|
|
|
Background: Vitamin D has been recently shown to play important roles in the functioning of various systems. Most of the current analytical methods for measuring vitamin D levels are based on immunoassays. We simultaneously measured the levels of 25-hydroxyvitamin D3 [ 25(OH)D3 ] and 25-hydroxyvitamin D2 [ 25(OH)D2 ] in human serum by performing ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) after Diels-Alder derivatization with 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD) and evaluated the performance of our method.
Methods: After liquid-liquid extraction, samples were dried under N2 at 50℃ for 1 hr followed by Diels-Alder derivatization with ethyl acetate containing 0.1 mg/mL PTAD. The samples were resuspended in 60 μL of methanol:10 mM ammonium formate solution (1:1, V/V). C18 UPLC column and positive ion multiple reaction monitoring transitions such as m/z 558.35→298.1, 25(OH)D3; m/z 570.35→298.1, 25(OH)D2; and m/z 564.35→298.1, hexadeuterated-25(OH)D3 were used for UPLC-MS/MS.
Results: The within-run imprecision (CVs) for 25(OH)D3 and 25(OH)D2 were 3.5-4.0% and 3.8-4.2%, respectively, and the corresponding between-run CVs were 3.3-5.5% and 4.7-5.8%. The lower limit of quantification for 25(OH)D3 and 25(OH)D2 were 0.5 and 1.0 ng/mL, respectively. The curve for interassay calibration variability data obtained over concentrations of 0-120 ng/mL for 25(OH)D3 and 0-90 ng/mL for 25(OH)D2 was linear and reproducible [ 25(OH)D3, R2=0.993; 25(OH)D2, R2=0.998]. The total 25(OH)D levels in Koreans (average, 18.7 ng/mL) were lower than those in American Caucasians, and the percentage of people with total 25(OH)D levels under 10 ng/mL was 8.1%.
Conclusions: Our method to measure 25(OH)D3 and 25(OH)D2 levels by performing UPLC-MS/MS after PTAD derivatization showed good performance as a sensitive and reproducible method for routine analysis of vitamin D status.
|
|
|
KEYWORD
|
|
|
Vitamin D, 4-phenyl-1, 2, 4-triazoline-3, 5-dione (PTAD), Tandem mass spectrometry, Ultra performance liquid chromatography, Immunoassay
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|
|