Development of quantitative 1H-NMR method for serum iron with application to infectious diseases

Abstract

Accurate quantification methods for biologically important elements are crucial for the diagnosis, treatment and monitoring of infectious diseases. Current methods are chemistry based, expensive, time consuming and are not designed for bio-fluid analysis. This study aims to add an array of information obtained from 1H-NMR serum metabolomics by developing a quantitative 1H-NMR method for serum iron quantification. 1H-NMR is a robust, information rich technology that is capable of synchronously quantifying and identifying biomolecules. Unfortunately, 1H-NMR can only analyse compounds with C-H bonds hence it cannot analyse iron. Chelating agents like EDTA and DFO chelate iron and make iron analysis possible. Excess EDTA was used to develop an 1H-NMR method to quantify Fe, Zn, K, Mg and Ca. Mg, Ca and Zn were quantified whilst K and Fe could not be quantified at physiological pH range. Further, DFO a ferric ion (Fe3+) chelating agent was used in excess and in the presence of a catalyst to develop a method for serum iron quantification, but the final prepared serum sample was unstable over time. Additional research on higher field strength catalyst(s) that can transfer more iron from iron binding proteins, as well as methods of stabilizing the final prepared serum sample to quench chemical reactions must be done.