An inter-laboratory comparison for determination of cortisol in saliva

Anne Helene Garde*, Åse Marie Hansen, Thomas Block Nikolajsen

*Corresponding author af dette arbejde

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

49 Citationer (Scopus)

Abstract

An inter-laboratory comparison study for cortisol in saliva is reported in the present study. Nine laboratories representing four different methods participated in the study. Each laboratory measured five blind samples prepared from natural saliva spiked with a pure certified reference material in the range 0-70 nmol/L. The average observed values were established as means of eight laboratories, because one laboratory was excluded as an outlier. The natural content of cortisol in the pooled saliva was 6.8 nmol/L. The recovery of the certified reference material was 83%-131% (164% for the outlying laboratory). For five laboratories the 95%-confidence intervals of the recoveries did not cover 100%. The standard deviations for a concentration of 10 nmol/L were estimated for each laboratory. They were 0.64-1.67 nmol/L (6.26 nmol/L for the outlying laboratory). The present study emphasizes the need for an external proficiency-testing scheme and a certified reference material for cortisol in saliva.

OriginalsprogEngelsk
TidsskriftAccreditation and Quality Assurance
Vol/bind8
Udgave nummer1
Sider (fra-til)16-20
Antal sider5
ISSN0949-1775
DOI
StatusUdgivet - 1 jan. 2003

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