Journal Pre-proof 15 N-labelled nitrite/nitrate tracer analysis by LC-MS/MS: Urinary and fecal excretion of nitrite/nitrate following oral administration to mice Chiung-Wen Hu, Yuan-Jhe Chang, Cheng-Chieh Yen, Jian-Lian Chen, Rajendra Bose Muthukumaran, Mu-Rong Chao PII: S0891-5849(19)31063-9 DOI: https://doi.org/10.1016/j.freeradbiomed.2019.08.005 Reference: FRB 14372 To appear in: Free Radical Biology and Medicine Received Date: 25 June 2019 Revised Date: 30 July 2019 Accepted Date: 6 August 2019 Please cite this article as: C.-W. Hu, Y.-J. Chang, C.-C. Yen, J.-L. Chen, R.B. Muthukumaran, M.-R. Chao, 15 N-labelled nitrite/nitrate tracer analysis by LC-MS/MS: Urinary and fecal excretion of nitrite/ nitrate following oral administration to mice, Free Radical Biology and Medicine (2019), doi: https:// doi.org/10.1016/j.freeradbiomed.2019.08.005. This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. © 2019 Published by Elsevier Inc.