Measurement of carnitine precursors, ε-trimethyllysine and γ-butyrobetaine in human serum by tandem mass spectrometry

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

“…The L-carnitine concentration was the same as the levels determined previously (Primassin and Spiekerkoetter, 2010). The GBB level was in agreement with previously published data (Hirche et al, 2009;Terada et al, 1999). The developed assay allows the simultaneous quantification of TMAO, L-carnitine and γ-butyrobetaine from human blood plasma.…”

“…The l ‐carnitine concentration was the same as the levels determined previously (Primassin and Spiekerkoetter, ). The GBB level was in agreement with previously published data (Hirche et al ., ; Terada et al, ).…”

Carnitine biosynthesis in mammals

“…Agents used for the derivative formation of TML include o-phthalaldehyde [83][84][85], phenylisothiocyanate [86] and 1-fluoro-2,4-dinitrobenzene [82]. More recently, a method to measure TML in plasma by tandem MS has been described [87]. This method uses two subsequent derivativeformation steps, propylation and acetylation, to circumvent the interference of homoarginine, followed by tandem MS analysis.…”

“…The concentration of TML in plasma is relatively constant in both human [85,87,88] and rat [83,89], ranging from 0.2 to 1.3 µM. Plasma levels of TML have been shown to correlate with body mass [88].…”

“…These methods, however, are rather labourintensive and require considerable amounts of sample. More recently, Sawada and colleagues [87,99] have described an assay based on tandem MS to measure butyrobetaine in plasma. The use of this technique makes prior purification of butyrobetaine unnecessary.…”