Quantitative analysis of plasma acylcarnitines using gas chromatography chemical ionization mass fragmentography.
A stable isotope dilution gas chromatography chemical ionization mass spectrometry (GC-CI-MS) method was developed for the quantitative profiling of plasma acylcarnitines. The clean-up procedure was comprised of a solid-phase cation exchange extraction using PRS-columns from which the acylcarnitines were eluted with a barium chloride solution. Isolated acylcarnitines were transformed into acyloxylactones and analyzed by positive GC-CI-MS using isobutane as reactant gas. The selected monitoring of a common ion at m/z [85]+ and the protonated molecular ion enabled a selective and sensitive detection of all C2-C18 acylcarnitines. An accurate quantitation was achieved by the use of stable isotope-labeled internal standards (C2-C18) and acylcarnitines could be analyzed in the sub-nanomolar range. Control values for C2-C18 acylcarnitines in plasma were established. Concentrations ranged from 0.02 micromol/L for C14-acylcarnitine to 4.90 micromol/L for C2-acylcarnitine. The diagnostic suitability of the method was demonstrated for patients with medium-chain acyl-CoA dehydrogenase deficiency and very long-chain acyl-CoA dehydrogenase deficiency.
Costa
C G
CG
Department of Clinical Chemistry, Free University Hospital, Amsterdam, The Netherlands.
Struys
E A
EA
Bootsma
A
A
ten Brink
H J
HJ
Dorland
L
L
Tavares de Almeida
I
I
Duran
M
M
Jakobs
C
C
D042964:Acyl-CoA Dehydrogenase; D044942:Acyl-CoA Dehydrogenase, Long-Chain / Q000172:deficiency*; D000215:Acylation; D002331:Carnitine / Q000031:analogs & derivatives* / Q000097:blood; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D007223:Infant; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D042964:Acyl-CoA Dehydrogenase; D044942:Acyl-CoA Dehydrogenase, Long-Chain; D002331:Carnitine