Issue 18, 2012

Eliminating the dication-induced intersample chemical-shift variations for NMR-based biofluid metabonomic analysis

Abstract

NMR-based urinary metabonomic analysis is an essential aspect of systems biology for understanding mammalian physiology and pathophysiology though intersample chemical-shift variations can cause serious problems. Here, we report two optimized and validated methods to eliminate such variations resulting from intersample differences in pH and dication concentration. We found that the Ca2+ concentration was 7.41 ± 3.48, 1.03 ± 0.34 and 0.87 ± 0.52 mM whereas the Mg2+ concentration was 3.02 ± 1.41, 2.65 ± 1.20 and 0.80 ± 0.59 mM in rat, mouse and human urine samples, respectively; urinary Ca–EDTA, Mg–EDTA and free EDTA had spin–lattice relaxation time values (600.13 MHz) of 0.38, 0.41 and 0.55 s, respectively. We also found that the combined treatments with potassium fluoride, phosphate buffer and a small amount of K3EDTA eliminated intersample chemical-shift variations for all metabolites. EDTA treatment followed with phosphate buffer also achieved similar results although resonances from EDTA and its complexes obscured some metabolite signals. We systematically optimized the amount of additives for rat, mouse and human urine samples taking into consideration the pH control, signal-to-noise ratio and intersample uniformity for metabolite chemical-shifts. Based on thorough validation, we established some optimized procedures for rat, mouse and human urine, respectively. By eliminating both pH and dication effects, these methods enable the reduction of intersample chemical-shift variations to 1.5 Hz for all metabolites. The methods will offer ensured data quality for high-throughput, especially robotic urinary metabonomics studies with no need for peak alignments or corrections.

Graphical abstract: Eliminating the dication-induced intersample chemical-shift variations for NMR-based biofluid metabonomic analysis

Supplementary files

Article information

Article type
Paper
Submitted
23 Mar 2012
Accepted
01 Jul 2012
First published
03 Jul 2012

Analyst, 2012,137, 4209-4219

Eliminating the dication-induced intersample chemical-shift variations for NMR-based biofluid metabonomic analysis

L. Jiang, J. Huang, Y. Wang and H. Tang, Analyst, 2012, 137, 4209 DOI: 10.1039/C2AN35392J

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements