Determination of trimethylamine-N-oxide in combination with l-carnitine and γ-butyrobetaine in human plasma by UPLC/MS/MS

An ultra‐high‐performance liquid chromatography–mass spectrometry (UPLC/MS/MS) method was developed and validated for the quantification of trimethylamine‐N‐oxide (TMAO) simultaneously with TMAO‐related molecules l‐carnitine and γ‐butyrobetaine (GBB) in human blood plasma. The separation of analytes was achieved using a Hydrophilic interaction liquid chromatography (HILIC)‐type column with ammonium acetate–acetonitrile as the mobile phase. TMAO determination was validated according to valid US Food and Drug Administration guidelines. The developed method was successfully applied to plasma samples from healthy volunteers. Copyright © 2015 John Wiley & Sons, Ltd.