Intra- and Interlaboratory Reproducibility of Ultra Performance Liquid Chromatography-Time-of-Flight Mass Spectrometry for Urinary Metabolic Profiling - Benton, HP; Want, E; Keun, HC; Amberg, A; Plumb, RS; Goldfain-Blanc, F; Walther, B; Reily, MD; Lindon, JC; Holmes, E; Nicholson, JK; Ebbels, TMD (ANALYTICAL CHEMISTRY, 2012)