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. 2011 Feb;32(1):5–31.

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The contents of articles or advertisements in The Clinical Biochemist – Reviews are not to be construed as official statements, evaluations or endorsements by the AACB, its official bodies or its agents. Statements of opinion in AACB publications are those of the contributors. Print Post Approved - PP255003/01665. Copyright © 2005 The Australasian Association of Clinical Biochemists Inc. No literary matter in The Clinical Biochemist – Reviews is to be reproduced, stored in a retrieval system or transmitted in any form by electronic or mechanical means, photocopying or recording, without permission. Requests to do so should be addressed to the Editor. ISSN 0159 – 8090

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Figure 3. — Comparison of HPLC-UV (A) and LC-MS/MS (B) chromatograms of urinary free cortisol measurements of the same patient sample that contains potentially interfering substances (carbamazepine). (A) Several potentially interfering peaks are visible on HPLC-UV, with one of the carbamazepine metabolites co-eluting with cortisol and the cortisone peak being barely separated from the cortisol peak, despite a run time of 30 minutes. (B) No interferences are seen by LC-MS/MS with only 3 minutes run time and the cortisone peak shows baseline separation from the cortisol peak. Note the cortisol isotopic internal standard overlaying the cortisol peak. Reprinted from Taylor *et al*. (Clin Chem 2002;48:1511–9) with permission from Clinical Chemistry.

Figure 3.