Simultaneous quantitation of folates, flavins and B6 metabolites in human plasma by LC–MS/MS assay: Applications in colorectal cancer

Publication date: 5 September 2018Source: Journal of Pharmaceutical and Biomedical Analysis, Volume 158Author(s): Isaac Asante, Hua Pei, Eugene Zhou, Siyu Liu, Darryl Chui, EunJeong Yoo, Stan G. LouieAbstractAn analytical method using electrospray ionization and high- performance liquid chromatography/tandem mass spectrometry (LC/ESI–MS/MS) was developed to quantify the vitamin B metabolites found in the folate one-carbon metabolism, using 50 μL of human plasma. Analytes in plasma were extracted using protein precipitation after being stabilized in 1% ascorbic acid. The analytes were separated using a Kinetex 2.6 μm Pentafluorophenyl (2.1 × 30 mm) column utilizing a gradient mobile phase system of 0.1% formic acid in water and 100% acetonitrile in a 13.2 min run. The MS detector run using a positive multiple reaction monitoring with parameters optimized for each analyte’s ion pair. The assay was selective and linear for all analytes at defined dynamic ranges. The recoveries were generally above 80% except for the folate metabolites whose recoveries dipped possibly due to the drying process. The inter-day precision (%coefficient of variation) and accuracy (%calculated concentration of the nominal concentrations) for six replicates of all quality control samples were ≤14% and within 12.2%, respectively. The lower limit of quantification ranged from 0.2 to 3.9 nM. No significant instability was observed after repeated freezing and thawing or in processed s...
Source: Journal of Pharmaceutical and Biomedical Analysis - Category: Drugs & Pharmacology Source Type: research