1. Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
2. Department of Surgery, Baylor College of Medicine, Houston, Texas 77030, United States
3. MS4Life Laboratory of Mass Spectrometry, Health Sciences Postgraduate Program, Universidade São Francisco, Bragança Paulista, SP 12916-900, Brazil
4. Department of Surgery, MD Anderson Cancer Center, Houston, Texas 77030, United States
5. Thermo Fisher Scientific, 28199 Bremen, Germany