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Sandra R Dahl, Ingrid Nermoen, Ingeborg Brønstad, Eystein S Husebye, Kristian Løvås and Per M Thorsby

for the patient’s age and sex. However, current immunoassays for testosterone are prone to interferences in the female reference range (low levels of testosterone) and can be inaccurate ( 7 , 8 , 9 ). Liquid chromatography–tandem mass spectrometry

Open access

Mélanie Rouleau, Francis Lemire, Michel Déry, Benoît Thériault, Gabriel Dubois, Yves Fradet, Paul Toren, Chantal Guillemette, Louis Lacombe, Laurence Klotz, Fred Saad, Dominique Guérette and Frédéric Pouliot

). Contemporary electrochemiluminescent immunoassay methods have a lower LLOQ (around 0.4 nM), thus lower castration testosterone levels are now targeted (<0.7 nM) ( 10 ). Mass spectrometry (MS) has been shown to be more sensitive and accurate than immunoassay

Open access

T P Parikh, B Stolze, Y Ozarda, J Jonklaas, K Welsh, L Masika, M Hill, A DeCherney and S J Soldin

of high-performance liquid chromatography (HPLC) in conjunction with tandem mass spectrometry (MS) is increasingly becoming the method of choice for clinical testing of hormone levels ( 5 , 6 , 15 , 16 , 17 ). Given its high sensitivity

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Jia Li, Yan Zhao, Caoxin Huang, Zheng Chen, Xiulin Shi, Long Li, Zhong Chen and Xuejun Li

exercise using untargeted ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) technology. Altered metabolites and metabolic pathways are established and may help explain the mechanism underlying

Open access

Paal Methlie, Steinar Hustad, Ralf Kellman, Bjørg Almås, Martina M Erichsen, Eystein S Husebye and Kristian Løvås

's syndrome (CS) and congenital adrenal hyperplasia, male hypogonadism and female hyperandrogenism. Although immunoassays have largely been used to measure steroid hormones, over the last decade, mass spectrometry (MS) has increasingly been adopted as it

Open access

Jean-Benoît Corcuff, Laurence Chardon, Ines El Hajji Ridah and Julie Brossaud

electrochemical detection ( 18 , 19 , 20 ). Recently, liquid chromatography coupled to mass spectrometry has been used for the detection and quantification of urinary as well as serum 5HIAA ( 21 , 22 , 23 ). Obviously, these last 5HIAA assays after HPLC

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Fiona Broughton Pipkin, Hiten D Mistry, Chandrima Roy, Bernhard Dick, Jason Waugh, Rebecca Chikhi, Lesia O Kurlak and Markus G Mohaupt

have used immunoassays which have the problem of steroid cross reactivity (20, 21) . We have addressed this problem by utilising gas chromatography-mass spectrometry (GC-MS) (22) . In addition, we have measured steroids in 24 h urine collections

Open access

M P Schuijt, C G J Sweep, R van der Steen, A J Olthaar, N M M L Stikkelbroeck, H A Ross and A E van Herwaarden

chromatography tandem mass spectrometry (ED-LC-MS/MS). LC-MS/MS enables the accurate, specific and matrix-independent measurement of testosterone with direct calibration. Equilibrium dialysis enables to separate the free- from protein-bound testosterone with

Open access

Aneta Gawlik, Michael Shmoish, Michaela F Hartmann, Stefan A Wudy, Zbigniew Olczak, Katarzyna Gruszczynska and Ze’ev Hochberg

ultrasonography – L1 L , or both – L1 AL ) where defined as liver disease – L1 as compared to L0 – without markers of liver disease. Gas chromatography-mass spectrometry (GC-MS) of urinary steroids Steroid metabolites in 24-h urine samples were analyzed by

Open access

J A Tamblyn, C Jenkinson, D P Larner, M Hewison and M D Kilby

stored at −80°C until use. Quantitative analysis of urinary de-conjugated vitamin D metabolites in spot urine samples was performed using a novel liquid chromatography tandem-mass spectrometry (LC–MS/MS) methodology. This was optimised from a method