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Updated: Jan 1, 2026

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Published on: September 21, 2014
Citrate NMR peak irreproducibility in blood samples after reacquisition of spectra
Munsoor A Hanifa1,2,3, Raluca G Maltesen2, Bodil S Rasmussen2,3
1Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, 9220, Aalborg, Denmark.
Background:
In our metabolomics studies we have noticed that repeated NMR acquisition on the same sample can result in altered metabolite signal intensities.
Aims:
To investigate the reproducibility of repeated NMR acquisition on selected metabolites in serum and plasma from two large human metabolomics studies.
Methods:
Two peak regions for each metabolite were integrated and changes occurring after reacquisition were correlated.
Results:
Integral changes were generally small, but serum citrate signals decreased significantly in some samples.
Conclusions:
Several metabolite integrals were not reproducible in some of the repeated spectra. Following established protocols, randomising analysis order and biomarker validation are important.
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