Portal de Periódicos da CAPES

Determination of carnitine and acylcarnitines in plasma by high‐performance liquid chromatography/electrospray ionization ion trap tandem mass spectrometry

2004; Wiley; Volume: 18; Issue: 11 Linguagem: Inglês

10.1002/rcm.1470

1097-0231

Laurence Vernez, Markus R. Wenk, Stephan Krähenbühl,

Infectious Encephalopathies and Encephalitis

Abstract A high‐performance liquid chromatography/mass spectrometry method was developed for the determination of carnitine, its biosynthetic precursor butyrobetaine, and eight acylcarnitines in plasma. The procedure includes a solid‐phase extraction for carnitine and short‐ and medium‐chain acylcarnitines, and a liquid‐liquid extraction for protein‐bound long‐chain acylcarnitines, followed by separation on a reversed‐phase column in the presence of a volatile ion‐pairing reagent. Detection was achieved using an ion‐trap mass spectrometer run in the tandem mass spectrometry (MS/MS) mode. The choice of the matrix for calibrators, used for quantification of these endogenous compounds, was also investigated. Validation was performed for standard quality controls diluted with 4% bovine serum albumin solution and for spiked plasma quality control samples at concentrations between 0.5 and 80 μmol/L, depending on the compound. Intra‐ and inter‐day precisions for the determination of carnitine were below 3.4% and accuracies were between 95.2 and 109.0%. Application of the method to the diagnosis of pathological acylcarnitine profiles of metabolic disorders in a patient suffering from methylmalonic aciduria is presented. The method allows quantification of carnitine, butyrobetaine, acetylcarnitine and propionylcarnitine, and semiquantitative analysis of medium‐ and long‐chain acylcarnitines. In contrast with other methods, no derivatization step is needed. Copyright © 2004 John Wiley & Sons, Ltd.