title: Erratum to: Sequence Elucidation of an Unknown Cyclic Peptide of High Doping Potential by ETD and CID Tandem Mass Spectrometry.
authors.affiliation: School of Veterinary Medicine, University of Pennsylvania, New Bolton Center Campus, 382 West Street Road, Kennett Square, PA, 19348, USA. guanf@vet.upenn.edu.
authors.forename: Fuyu
authors.initials: F
authors.lastname: Guan
authors.affiliation: School of Veterinary Medicine, University of Pennsylvania, New Bolton Center Campus, 382 West Street Road, Kennett Square, PA, 19348, USA. ubohcorn@vet.upenn.edu.|PA Equine Toxicology and Research Center, West Chester University, 220 East Rosedale Ave., West Chester, PA, 19382, USA. ubohcorn@vet.upenn.edu.
authors.forename: Cornelius E
authors.initials: CE
authors.lastname: Uboh
authors.affiliation: School of Veterinary Medicine, University of Pennsylvania, New Bolton Center Campus, 382 West Street Road, Kennett Square, PA, 19348, USA.
authors.forename: Lawrence R
authors.initials: LR
authors.lastname: Soma
authors.affiliation: PA Equine Toxicology and Research Center, West Chester University, 220 East Rosedale Ave., West Chester, PA, 19382, USA.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Rudy