Direct analysis of [6,6-2H2]glucose and [U-13C6]glucose dry blood spot enrichments by LC–MS/MS.

A liquid chromatography tandem mass spectrometry (LC–MS/MS) using multiple reaction monitoring (MRM) in a triple-quadrupole scan mode was developed and comprehensively validated for the determination of [6,6- 2 H 2 ]glucose and [U- 13 C 6 ]glucose enrichments from dried blood spots (DBS) without prior derivatization. The method is demonstrated with dried blood spots obtained from rats administered with a primed-constant infusion of [U- 13 C 6 ]glucose and an oral glucose load enriched with [6,6- 2 H 2 ]glucose. The sensitivity is sufficient for analysis of the equivalent to <5 μL of blood and the overall method was accurate and precise for the determination of DBS isotopic enrichments. [ABSTRACT FROM AUTHOR]