Evaluation of13C- and2H-labeled internal standards for the determination of amphetamines in biological samples, by reversed-phase ultra-high performance liquid chromatography–tandem mass spectrometry
Thomas Berg, Morten Karlsen, Åse Marit Leere Øiestad, Jon Eigill Johansen, Huiling Liu, Dag Helge Strand
• Several new 13C labeled internal standards (ISs) used for the first time as ISs. • 13C labeled ISs better suited than 2H labeled ISs in RP LC–MS/MS analysis. • 13C labeled ISs behave as their analytes in chromatographic separations. • ISs with few 2H are better suited than those with many 2H substitutes. • No differences between extraction recovery of 13C- and 2H ISs were observed.
