title: Fragmentation patterns of boron-dipyrromethene (BODIPY) dyes by electrospray ionization high-resolution tandem mass spectrometry.
abstract: BACKGROUND
  4,4-Difluoro-4-bora-3a,4a-diaza-s-indacene derivatives (BODIPYs) are fluorescent organic dyes that are widely used as non-radioactive labels in biological analyses. The fragmentation behaviour of ten structurally related BODIPYs was studied using tandem mass spectrometry (MS/MS), to support the structural elucidation process during synthesis.
  
  
  METHODS
  The BODIPYs were investigated by electrospray ionization (ESI)-MS/MS, utilizing collision-induced dissociation (CID) data from triple quadrupole MS and high-resolution, accurate mass CID data from Fourier transform ion cyclotron resonance (FTICR) experiments.
  
  
  RESULTS
  Unusual radical molecular cations ([M](+•)) were formed directly during the ESI process. These radical species dissociated into a large range of product ions during the subsequent CID experiments. Superimposed dissociations originating from parallel [M](+•) and [M+H](+) decompositions significantly complicated the interpretation of the MS/MS spectra.
  
  
  CONCLUSIONS
  Detailed dissociation mechanisms were proposed in this study for BODIPY dyes. The elemental formulae of CID product ions were unambiguously assigned using FTICR-MS and unique fragment ions were discovered for the rapid identification of methyl, ethyl, butyl, tert-butyl, and phenyl substituents of individual dyes in BODIPY synthesis mixtures by low-resolution MS.
authors.affiliation: Institute of Bioanalytical Chemistry, Saarland University, 66123, Saarbrücken, Germany.
authors.forename: Yulin
authors.initials: Y
authors.lastname: Qi
authors.affiliation: Institute of Bioanalytical Chemistry, Saarland University, 66123, Saarbrücken, Germany.
authors.forename: Timon
authors.initials: T
authors.lastname: Geib
authors.affiliation: Biophysical Chemistry, Saarland University, 66123, Saarbrücken, Germany.
authors.forename: Anh-Minh
authors.initials: AM
authors.lastname: Huynh
authors.affiliation: Biophysical Chemistry, Saarland University, 66123, Saarbrücken, Germany.
authors.forename: Gregor
authors.initials: G
authors.lastname: Jung
authors.affiliation: Institute of Bioanalytical Chemistry, Saarland University, 66123, Saarbrücken, Germany.
authors.forename: Dietrich A
authors.identifier: http://orcid.org/0000-0003-2820-1480
authors.initials: DA
authors.lastname: Volmer
mesh_terms: D001896:Boron Compounds / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: C095489:4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; D001896:Boron Compounds