Analysis of carnitine biosynthesis metabolites in urine by HPLC-electrospray tandem mass spectrometry

Frédéric M. Vaz, B. Melegh, J. Bene, Dean Cuebas, Douglas A. Gage, Albert Bootsma, Peter Vreken, Albert H. Van Gennip, Loran L. Bieber, Ronald J A Wanders

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

Background: We developed a method to determine the urinary concentrations of metabolites in the synthetic pathway for carnitine from N6-trimethyllysine and applied this method to determine their excretion in control individuals. In addition, we investigated whether newborns are capable of carnitine synthesis from deuterium-labeled N6-trimethyllysine. Methods: Urine samples were first derivatized with methyl chloroformate. Subsequently, the analytes were separated by ion-pair, reversed-phase HPLC and detected online by electrospray tandem mass spectrometry. Stable-isotope-labeled reference compounds were used as internal standards. Results: The method quantified all carnitine biosynthesis metabolites except 4-N-trimethylaminobutyraldehyde. Detection limits were 0.05-0.1 μmol/L. The interassay imprecision (CV) for urine samples with added compounds was 6-12%. The intraassay imprecision (CV) was 1-5% (3-10 μmol/L). Recoveries were 94-106% at 10-20 μmol/L and 98-103% at 100-200 μmol/L. The mean (SD) excretions of N6-trimethyllysine and 3-hydroxy-N6-trimethyllysine were 2.8 (0.8) and 0.45 (0.15) mmol/mol creatinine, respectively. γ-Butyrobetaine and carnitine excretions were more variable with values of 0.27 (0.21) and 15 (12) mmol/mol creatinine, respectively. After oral administration of deuterium-labeled N6-trimethyllysine, all urines of newborns contained deuterium-labeled N6-trimethyllysine, 3-hydroxy-N6-trimethyllysine, γ-butyrobetaine, and carnitine. Conclusions: HPLC in combination with electrospray ionization tandem mass spectrometry allows rapid determination of urinary carnitine biosynthesis metabolites. Newborns can synthesize carnitine from exogenous N6-trimethyllysine, albeit at a low rate.

Original languageEnglish
Pages (from-to)826-834
Number of pages9
JournalClinical Chemistry
Volume48
Issue number6
Publication statusPublished - 2002

Fingerprint

Carnitine
Biosynthesis
Metabolites
Tandem Mass Spectrometry
Mass spectrometry
High Pressure Liquid Chromatography
Urine
Deuterium
Creatinine
Electrospray ionization
Electrospray Ionization Mass Spectrometry
trimethyllysine
Isotopes
Oral Administration
Limit of Detection
Ions
Recovery

ASJC Scopus subject areas

  • Clinical Biochemistry

Cite this

Vaz, F. M., Melegh, B., Bene, J., Cuebas, D., Gage, D. A., Bootsma, A., ... Wanders, R. J. A. (2002). Analysis of carnitine biosynthesis metabolites in urine by HPLC-electrospray tandem mass spectrometry. Clinical Chemistry, 48(6), 826-834.

Analysis of carnitine biosynthesis metabolites in urine by HPLC-electrospray tandem mass spectrometry. / Vaz, Frédéric M.; Melegh, B.; Bene, J.; Cuebas, Dean; Gage, Douglas A.; Bootsma, Albert; Vreken, Peter; Van Gennip, Albert H.; Bieber, Loran L.; Wanders, Ronald J A.

In: Clinical Chemistry, Vol. 48, No. 6, 2002, p. 826-834.

Research output: Contribution to journalArticle

Vaz, FM, Melegh, B, Bene, J, Cuebas, D, Gage, DA, Bootsma, A, Vreken, P, Van Gennip, AH, Bieber, LL & Wanders, RJA 2002, 'Analysis of carnitine biosynthesis metabolites in urine by HPLC-electrospray tandem mass spectrometry', Clinical Chemistry, vol. 48, no. 6, pp. 826-834.
Vaz, Frédéric M. ; Melegh, B. ; Bene, J. ; Cuebas, Dean ; Gage, Douglas A. ; Bootsma, Albert ; Vreken, Peter ; Van Gennip, Albert H. ; Bieber, Loran L. ; Wanders, Ronald J A. / Analysis of carnitine biosynthesis metabolites in urine by HPLC-electrospray tandem mass spectrometry. In: Clinical Chemistry. 2002 ; Vol. 48, No. 6. pp. 826-834.
@article{43244c21faae4b48a05e3eb7985ec471,
title = "Analysis of carnitine biosynthesis metabolites in urine by HPLC-electrospray tandem mass spectrometry",
abstract = "Background: We developed a method to determine the urinary concentrations of metabolites in the synthetic pathway for carnitine from N6-trimethyllysine and applied this method to determine their excretion in control individuals. In addition, we investigated whether newborns are capable of carnitine synthesis from deuterium-labeled N6-trimethyllysine. Methods: Urine samples were first derivatized with methyl chloroformate. Subsequently, the analytes were separated by ion-pair, reversed-phase HPLC and detected online by electrospray tandem mass spectrometry. Stable-isotope-labeled reference compounds were used as internal standards. Results: The method quantified all carnitine biosynthesis metabolites except 4-N-trimethylaminobutyraldehyde. Detection limits were 0.05-0.1 μmol/L. The interassay imprecision (CV) for urine samples with added compounds was 6-12{\%}. The intraassay imprecision (CV) was 1-5{\%} (3-10 μmol/L). Recoveries were 94-106{\%} at 10-20 μmol/L and 98-103{\%} at 100-200 μmol/L. The mean (SD) excretions of N6-trimethyllysine and 3-hydroxy-N6-trimethyllysine were 2.8 (0.8) and 0.45 (0.15) mmol/mol creatinine, respectively. γ-Butyrobetaine and carnitine excretions were more variable with values of 0.27 (0.21) and 15 (12) mmol/mol creatinine, respectively. After oral administration of deuterium-labeled N6-trimethyllysine, all urines of newborns contained deuterium-labeled N6-trimethyllysine, 3-hydroxy-N6-trimethyllysine, γ-butyrobetaine, and carnitine. Conclusions: HPLC in combination with electrospray ionization tandem mass spectrometry allows rapid determination of urinary carnitine biosynthesis metabolites. Newborns can synthesize carnitine from exogenous N6-trimethyllysine, albeit at a low rate.",
author = "Vaz, {Fr{\'e}d{\'e}ric M.} and B. Melegh and J. Bene and Dean Cuebas and Gage, {Douglas A.} and Albert Bootsma and Peter Vreken and {Van Gennip}, {Albert H.} and Bieber, {Loran L.} and Wanders, {Ronald J A}",
year = "2002",
language = "English",
volume = "48",
pages = "826--834",
journal = "Clinical Chemistry",
issn = "0009-9147",
publisher = "American Association for Clinical Chemistry Inc.",
number = "6",

}

TY - JOUR

T1 - Analysis of carnitine biosynthesis metabolites in urine by HPLC-electrospray tandem mass spectrometry

AU - Vaz, Frédéric M.

AU - Melegh, B.

AU - Bene, J.

AU - Cuebas, Dean

AU - Gage, Douglas A.

AU - Bootsma, Albert

AU - Vreken, Peter

AU - Van Gennip, Albert H.

AU - Bieber, Loran L.

AU - Wanders, Ronald J A

PY - 2002

Y1 - 2002

N2 - Background: We developed a method to determine the urinary concentrations of metabolites in the synthetic pathway for carnitine from N6-trimethyllysine and applied this method to determine their excretion in control individuals. In addition, we investigated whether newborns are capable of carnitine synthesis from deuterium-labeled N6-trimethyllysine. Methods: Urine samples were first derivatized with methyl chloroformate. Subsequently, the analytes were separated by ion-pair, reversed-phase HPLC and detected online by electrospray tandem mass spectrometry. Stable-isotope-labeled reference compounds were used as internal standards. Results: The method quantified all carnitine biosynthesis metabolites except 4-N-trimethylaminobutyraldehyde. Detection limits were 0.05-0.1 μmol/L. The interassay imprecision (CV) for urine samples with added compounds was 6-12%. The intraassay imprecision (CV) was 1-5% (3-10 μmol/L). Recoveries were 94-106% at 10-20 μmol/L and 98-103% at 100-200 μmol/L. The mean (SD) excretions of N6-trimethyllysine and 3-hydroxy-N6-trimethyllysine were 2.8 (0.8) and 0.45 (0.15) mmol/mol creatinine, respectively. γ-Butyrobetaine and carnitine excretions were more variable with values of 0.27 (0.21) and 15 (12) mmol/mol creatinine, respectively. After oral administration of deuterium-labeled N6-trimethyllysine, all urines of newborns contained deuterium-labeled N6-trimethyllysine, 3-hydroxy-N6-trimethyllysine, γ-butyrobetaine, and carnitine. Conclusions: HPLC in combination with electrospray ionization tandem mass spectrometry allows rapid determination of urinary carnitine biosynthesis metabolites. Newborns can synthesize carnitine from exogenous N6-trimethyllysine, albeit at a low rate.

AB - Background: We developed a method to determine the urinary concentrations of metabolites in the synthetic pathway for carnitine from N6-trimethyllysine and applied this method to determine their excretion in control individuals. In addition, we investigated whether newborns are capable of carnitine synthesis from deuterium-labeled N6-trimethyllysine. Methods: Urine samples were first derivatized with methyl chloroformate. Subsequently, the analytes were separated by ion-pair, reversed-phase HPLC and detected online by electrospray tandem mass spectrometry. Stable-isotope-labeled reference compounds were used as internal standards. Results: The method quantified all carnitine biosynthesis metabolites except 4-N-trimethylaminobutyraldehyde. Detection limits were 0.05-0.1 μmol/L. The interassay imprecision (CV) for urine samples with added compounds was 6-12%. The intraassay imprecision (CV) was 1-5% (3-10 μmol/L). Recoveries were 94-106% at 10-20 μmol/L and 98-103% at 100-200 μmol/L. The mean (SD) excretions of N6-trimethyllysine and 3-hydroxy-N6-trimethyllysine were 2.8 (0.8) and 0.45 (0.15) mmol/mol creatinine, respectively. γ-Butyrobetaine and carnitine excretions were more variable with values of 0.27 (0.21) and 15 (12) mmol/mol creatinine, respectively. After oral administration of deuterium-labeled N6-trimethyllysine, all urines of newborns contained deuterium-labeled N6-trimethyllysine, 3-hydroxy-N6-trimethyllysine, γ-butyrobetaine, and carnitine. Conclusions: HPLC in combination with electrospray ionization tandem mass spectrometry allows rapid determination of urinary carnitine biosynthesis metabolites. Newborns can synthesize carnitine from exogenous N6-trimethyllysine, albeit at a low rate.

UR - http://www.scopus.com/inward/record.url?scp=18444401117&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=18444401117&partnerID=8YFLogxK

M3 - Article

VL - 48

SP - 826

EP - 834

JO - Clinical Chemistry

JF - Clinical Chemistry

SN - 0009-9147

IS - 6

ER -