Determination of L-threonate in human plasma and urine by high performance liquid chromatography-tandem mass spectrometry.
A fast and selective HPLC-MS-MS method was established to determine L-threonate in human plasma and urine. Plasma and urine samples were extracted by protein precipitation and diluted with water, then chromatographed on an YMC J'Sphere C(18) column with methanol-acetonitrile-10mM ammonium acetate (20:5:75, v/v) as mobile phase, and at a flow rate of 0.2 ml/min. Detection was performed on a triple-quadrupole tandem mass spectrometer using negative electrospray ionization (ESI). Multiple reactions monitoring (MRM) was used and L-threonate was quantified by monitoring the ion transition of m/z 134.5-->74.7. The linear calibration curves of L-threonate in plasma and urine were obtained over the concentration range of 0.25-50 microg/ml and 2.5-500 microg/ml, respectively. Lower limit of quantitation was 0.25 and 2.5 microg/ml, respectively. Accuracy was within 85-115%, and intra- and inter-batch precision (R.S.D.%) were within +/-15%. The method proved to be accurate and specific, and was applied to the pharmacokinetic study of L-threonate in Chinese healthy subjects.
Clinical Pharmacology Research Center, Peking Union Medical College Hospital and Chinese Academy of Medical Sciences, Beijing 100730, China.
Hongyun
H
Wang
Ji
J
Jiang
Pei
P
Hu
D002087:Butyrates / Q000097:blood* / Q000493:pharmacokinetics / Q000652:urine*; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D012016:Reference Values; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D002087:Butyrates; C011369:threonic acid