Determination of cortisol production rates with contemporary liquid chromatography-mass spectrometry to measure cortisol-d3 dilution after infusion of deuterated tracer

Bethany J. Klopfenstein; Jonathan Q. Purnell; David D. Brandon; Lorne M. Isabelle; Andrea E. DeBarber

doi:10.1016/j.clinbiochem.2010.12.008

Determination of cortisol production rates with contemporary liquid chromatography-mass spectrometry to measure cortisol-d3 dilution after infusion of deuterated tracer

Bethany J. Klopfenstein, Jonathan Q. Purnell, David D. Brandon, Lorne M. Isabelle, Andrea E. DeBarber

Research output: Contribution to journal › Article › peer-review

15 Scopus citations

Abstract

Objectives: Measurement of 24-h cortisol production rate (CPR) using steady-state infusion of deuterated cortisol and analysis of stable-isotope dilution by MS is a valuable tool to examine hypothalamic-pituitary-adrenal axis activity in humans. We have developed and validated an improved method for measuring cortisol dilution with contemporary LC-MS technology. Design and methods: Plasma samples and calibrators were extracted with ethylacetate. LC-MS was performed with a Surveyor HPLC and TSQ Quantum triple-quadrupole mass spectrometer equipped with an atmospheric pressure chemical ionization (APCI) source. Results: Selectivity was improved over previous methods via elimination of an interferent identified as 20β-dihydrocortisol. The LLOQ for cortisol-d₃ was 2.73nmol/L and LOD 1.37nmol/L. Plasma calibrators were linear over the concentration range 1.5-10% cortisol-d₃, with correlation coefficients >0.995. Conclusions: This APCI LC-MS method offers simplified sample work-up and analysis and enables selective detection of the low concentration of cortisol-d₃ infused for determination of 24-h CPR.

Original language	English (US)
Pages (from-to)	430-434
Number of pages	5
Journal	Clinical Biochemistry
Volume	44
Issue number	5-6
DOIs	https://doi.org/10.1016/j.clinbiochem.2010.12.008
State	Published - Apr 2011

Keywords

20β-Dihydrocortisol
Atmospheric pressure chemical ionization
Cortisol production rate
Liquid chromatography-mass spectrometry
Plasma

ASJC Scopus subject areas

Clinical Biochemistry

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10.1016/j.clinbiochem.2010.12.008

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Determination of cortisol production rates with contemporary liquid chromatography-mass spectrometry to measure cortisol-d3 dilution after infusion of deuterated tracer. / Klopfenstein, Bethany J.; Purnell, Jonathan Q.; Brandon, David D. et al.
In: Clinical Biochemistry, Vol. 44, No. 5-6, 04.2011, p. 430-434.

Research output: Contribution to journal › Article › peer-review

@article{0a681825fa41419b8e345425058f6efa,

title = "Determination of cortisol production rates with contemporary liquid chromatography-mass spectrometry to measure cortisol-d3 dilution after infusion of deuterated tracer",

abstract = "Objectives: Measurement of 24-h cortisol production rate (CPR) using steady-state infusion of deuterated cortisol and analysis of stable-isotope dilution by MS is a valuable tool to examine hypothalamic-pituitary-adrenal axis activity in humans. We have developed and validated an improved method for measuring cortisol dilution with contemporary LC-MS technology. Design and methods: Plasma samples and calibrators were extracted with ethylacetate. LC-MS was performed with a Surveyor HPLC and TSQ Quantum triple-quadrupole mass spectrometer equipped with an atmospheric pressure chemical ionization (APCI) source. Results: Selectivity was improved over previous methods via elimination of an interferent identified as 20β-dihydrocortisol. The LLOQ for cortisol-d3 was 2.73nmol/L and LOD 1.37nmol/L. Plasma calibrators were linear over the concentration range 1.5-10% cortisol-d3, with correlation coefficients >0.995. Conclusions: This APCI LC-MS method offers simplified sample work-up and analysis and enables selective detection of the low concentration of cortisol-d3 infused for determination of 24-h CPR.",

keywords = "20β-Dihydrocortisol, Atmospheric pressure chemical ionization, Cortisol production rate, Liquid chromatography-mass spectrometry, Plasma",

author = "Klopfenstein, {Bethany J.} and Purnell, {Jonathan Q.} and Brandon, {David D.} and Isabelle, {Lorne M.} and DeBarber, {Andrea E.}",

note = "Funding Information: This work was supported by NIH grants K23 RR021368 (B.J.K.), R01 DK068146 (J.Q.P.), R03 DK61996 (J.Q.P.), K23 DK002689 (J.Q.P.), UL1 RR024140 (Oregon Clinical and Translational Research Institute (OCTRI)), and an OHSU General Clinical Research Center grant ( M01 RR00334 ). The work was accomplished using instrumentation housed in the OHSU Bioanalytical Shared Resource. In addition, the authors gratefully acknowledge the expert technical assistance of Kenneth Newcomb in the development of these methodologies.",

year = "2011",

month = apr,

doi = "10.1016/j.clinbiochem.2010.12.008",

language = "English (US)",

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T1 - Determination of cortisol production rates with contemporary liquid chromatography-mass spectrometry to measure cortisol-d3 dilution after infusion of deuterated tracer

AU - Klopfenstein, Bethany J.

AU - Purnell, Jonathan Q.

AU - Brandon, David D.

AU - Isabelle, Lorne M.

AU - DeBarber, Andrea E.

N1 - Funding Information: This work was supported by NIH grants K23 RR021368 (B.J.K.), R01 DK068146 (J.Q.P.), R03 DK61996 (J.Q.P.), K23 DK002689 (J.Q.P.), UL1 RR024140 (Oregon Clinical and Translational Research Institute (OCTRI)), and an OHSU General Clinical Research Center grant ( M01 RR00334 ). The work was accomplished using instrumentation housed in the OHSU Bioanalytical Shared Resource. In addition, the authors gratefully acknowledge the expert technical assistance of Kenneth Newcomb in the development of these methodologies.

PY - 2011/4

Y1 - 2011/4

N2 - Objectives: Measurement of 24-h cortisol production rate (CPR) using steady-state infusion of deuterated cortisol and analysis of stable-isotope dilution by MS is a valuable tool to examine hypothalamic-pituitary-adrenal axis activity in humans. We have developed and validated an improved method for measuring cortisol dilution with contemporary LC-MS technology. Design and methods: Plasma samples and calibrators were extracted with ethylacetate. LC-MS was performed with a Surveyor HPLC and TSQ Quantum triple-quadrupole mass spectrometer equipped with an atmospheric pressure chemical ionization (APCI) source. Results: Selectivity was improved over previous methods via elimination of an interferent identified as 20β-dihydrocortisol. The LLOQ for cortisol-d3 was 2.73nmol/L and LOD 1.37nmol/L. Plasma calibrators were linear over the concentration range 1.5-10% cortisol-d3, with correlation coefficients >0.995. Conclusions: This APCI LC-MS method offers simplified sample work-up and analysis and enables selective detection of the low concentration of cortisol-d3 infused for determination of 24-h CPR.

AB - Objectives: Measurement of 24-h cortisol production rate (CPR) using steady-state infusion of deuterated cortisol and analysis of stable-isotope dilution by MS is a valuable tool to examine hypothalamic-pituitary-adrenal axis activity in humans. We have developed and validated an improved method for measuring cortisol dilution with contemporary LC-MS technology. Design and methods: Plasma samples and calibrators were extracted with ethylacetate. LC-MS was performed with a Surveyor HPLC and TSQ Quantum triple-quadrupole mass spectrometer equipped with an atmospheric pressure chemical ionization (APCI) source. Results: Selectivity was improved over previous methods via elimination of an interferent identified as 20β-dihydrocortisol. The LLOQ for cortisol-d3 was 2.73nmol/L and LOD 1.37nmol/L. Plasma calibrators were linear over the concentration range 1.5-10% cortisol-d3, with correlation coefficients >0.995. Conclusions: This APCI LC-MS method offers simplified sample work-up and analysis and enables selective detection of the low concentration of cortisol-d3 infused for determination of 24-h CPR.

KW - 20β-Dihydrocortisol

KW - Atmospheric pressure chemical ionization

KW - Cortisol production rate

KW - Liquid chromatography-mass spectrometry

KW - Plasma

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JO - Clinical Biochemistry

JF - Clinical Biochemistry

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ER -

Determination of cortisol production rates with contemporary liquid chromatography-mass spectrometry to measure cortisol-d3 dilution after infusion of deuterated tracer

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