Global metabolic profiling analysis on human urine by UPLC-TOFMS: issues and method validation in nutritional metabolomics.

Optimisation and method validation was assessed here for metabolic profiling analysis of urine samples using UPLC-TOFMS. A longer run time of 31 min revealed greater reproducibility, and the higher number of variables was identified as compared to shortened run times (10 and 26 min). We have also implemented two QC urine samples enabling the assessment of the quality and reproducibility of the data generated during the whole analytical workflow (retention time drift, mass precision and fluctuation of the ion responses over time). Based on the QC data, suitable standards for ensuring consistent analytical results for metabolomics applications using the UPLC-MS techniques are recommended.