Here we present a mixed-mode LC method that is MS compatible for the analysis of TCA cycle analytes as well as other related compounds without the use of sample derivatization or ion-pairing reagents. We applied this method for the analysis of urine from healthy, and breast cancer subjects. We further used statistical software tools in order to determine differences in analytes present as well as up- and downregulated analytes in theses samples.
Excellent analytical reproducibility is achieved as shown by the tight cluster of the QC samples in the PCA scores plot. The method was then used to show abundances of organic acid metabolites in both breast cancer positive and healthy urine.