摘要
A sensitive method based on high-performance liquid chromatography-tandem mass spectrometry （LC- MS/MS） has been developed for the simultaneous determination of folic acid （FA） and its active meta- bolite, 5-methyltetrahydrofolic acid （5-M-THF）, in human plasma. The analytes were extracted from plasma with methanol solution containing 10 mg/mL of 2-mercaptoethanol and 0.025% （v/v） ammonium hydroxide. FA and 5-M-THF were more stable after the addition of 2-mercaptoethanol and ammonium hydroxide in the sample preparation procedures of this study than they were in the previously published methods. Chromatographic separation was performed on a Hedera ODS-2 column using a gradient elution system of acetonitrile and 1 mM ammonium acetate buffer solution containing 0.6% formic acid as mobile phase. LC-MS/MS was carried out with an ESI ion-source and operated in the multiple reaction monitoring （MRM） mode. The assay was linear over the concentration ranges of 0.249-19.9 ng/mL for FA, and 5.05-50.5 ng/mL for 5-M-THF. The developed LC-MS/MS method offers increased sensitivity for quantification of FA and 5-M-THF in human plasma and was applicable to a pharmacokinetic study of FA and 5-M-THF.
A sensitive method based on high-performance liquid chromatography-tandem mass spectrometry （LC- MS/MS） has been developed for the simultaneous determination of folic acid （FA） and its active meta- bolite, 5-methyltetrahydrofolic acid （5-M-THF）, in human plasma. The analytes were extracted from plasma with methanol solution containing 10 mg/mL of 2-mercaptoethanol and 0.025% （v/v） ammonium hydroxide. FA and 5-M-THF were more stable after the addition of 2-mercaptoethanol and ammonium hydroxide in the sample preparation procedures of this study than they were in the previously published methods. Chromatographic separation was performed on a Hedera ODS-2 column using a gradient elution system of acetonitrile and 1 mM ammonium acetate buffer solution containing 0.6% formic acid as mobile phase. LC-MS/MS was carried out with an ESI ion-source and operated in the multiple reaction monitoring （MRM） mode. The assay was linear over the concentration ranges of 0.249-19.9 ng/mL for FA, and 5.05-50.5 ng/mL for 5-M-THF. The developed LC-MS/MS method offers increased sensitivity for quantification of FA and 5-M-THF in human plasma and was applicable to a pharmacokinetic study of FA and 5-M-THF.
