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Micro determination of cortisol and cortisone in umbilical cord blood by chemiluminescent high‐performance liquid chromatography
Author(s) -
Hasegawa Takeshi,
Kubo Hiroaki,
Shinozaki Koichi,
Nowatari Masahiko,
Ishii Masahiro
Publication year - 2010
Publication title -
biomedical chromatography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 65
eISSN - 1099-0801
pISSN - 0269-3879
DOI - 10.1002/bmc.1335
Subject(s) - chemistry , chromatography , chemiluminescence , cortisone , umbilical cord , high performance liquid chromatography , medicine , immunology , biology
A simple, sensitive and specific chemiluminescent high‐performance liquid chromatography method, based on the luminol reaction, for determination of serum cortisol and cortisone, was established. In infants, placental 11 β ‐hydroxysteroid dehydrogenase type 2 enzyme (11 β ‐HSD2) activity may affect adrenal function early after birth. The cortisol–cortisone ratio of serum concentrations in umbilical cord blood is an indicator of placental 11 β ‐HSD2 activity. The optimum conditions for the luminol reaction were determined to be 1.5 m M luminol, 0.6 M sodium hydroxide, 0.15 mm potassium hexacyanoferrate(III) and 200 m M potassium hexacyanoferrate (II). The calibration curves for cortisol and cortisone exhibited good linearity. The correlation coefficients of the calibration curves were 0.996. The intra‐ and inter‐day precisions were in the ranges: cortisol 7.0–12.2 and 4.4–9.2%, cortisone 5.3–7.0 and 6.2–9.9%. The recoveries of these steroids were in the ranges: cortisol 97–105%, cortisone 94–102%. The limits of detection were as follows: cortisol, 0.17 μg/dl; cortisone 0.15 μg/dl. This assay could be successfully applied to determination of the cortisol–cortiosone ratio of serum concentrations in umbilical cord bloods. Copyright © 2009 John Wiley & Sons, Ltd.