The NPC has published a paper detailing its analytical and preparative procedures for metabolic phenotyping of human urine by UPLC-MS.
For details, see the publication in Analytical Chemistry:
Development and Application of Ultra-Performance Liquid Chromatography-TOF MS for Precision Large Scale Urinary Metabolic Phenotyping
Matthew R. Lewis, Jake T. M. Pearce, Konstantina Spagou, Martin Green, Anthony C. Dona, Ada H. Y. Yuen, Mark David, David J. Berry, Katie Chappell, Verena Horneffer-van der Sluis, Rachel Shaw, Simon Lovestone, Paul Elliott, John Shockcor, John C. Lindon, Olivier Cloarec, Zoltan Takats, Elaine Holmes, and Jeremy K. Nicholson
Analytical Chemistry 2016 88 (18), 9004-9013