A short review of applications of liquid chromatography mass spectrometry based metabolomics techniques to the analysis of human urine

The applications of metabolomics as a methodology for providing better treatment and understanding human disease continue to expand rapidly. In this review, covering the last two years, the focus is on liquid chromatography-mass spectrometry (LC-MS) profiling of metabolites in urine. In LC-MS based metabolomics there are still problems with regard to: chromatographic separation, peak picking and alignment, metabolite identification, metabolite coverage, instrument sensitivity and data interpretation and in the case of urine sample normalisation. Progress has been made with regard to all of these issues during the period of the review. Of particular interest are the increasing use of orthogonal chromatographic methods for optimal metabolite coverage and the increasing adoption of receiver operator characteristic (ROC) curves for biomarker validation.