title: A practical approach to reduce interference due to in-source collision-induced dissociation of acylglucuronides in LC-MS/MS.
abstract: BACKGROUND
  In LC-MS/MS, glucuronide conjugated metabolites may convert back to the parent drug due to in-source collision-induced dissociation (CID).
  
  
  RESULTS
  During the bioanalysis of naproxen, it was noticed that naproxen acylglucuronide exhibited intense in-source CID to the naproxen [M+H](+) ion under positive ESI. However, no in-source CID of the acylglucuronide to the naproxen [M+NH(4)](+) adduct was observed. Furthermore, absolutely no in-source CID was detected under negative ESI. This phenomenon was not only observed for naproxen acylglucuronide but for eight other acylglucuronides compounds.
  
  
  CONCLUSIONS
  We have shown that monitoring the parent drug [M-H](-) or [M+NH(4)](+) whenever possible could be an easy approach used by bioanalytical scientists to minimize the impact of in-source CID of acylglucuronides to the parent drug.
authors.affiliation: Algorithme Pharma Inc, 575 Armand-Frappier, Laval, Québec, Canada, H7V 4B3.
authors.forename: Jean-Nicholas
authors.initials: JN
authors.lastname: Mess
authors.forename: Eugénie-Raphaelle
authors.initials: ER
authors.lastname: Bérubé
authors.forename: Milton
authors.initials: M
authors.lastname: Furtado
authors.forename: Fabio
authors.initials: F
authors.lastname: Garofolo
mesh_terms: D002851:Chromatography, High Pressure Liquid; D020719:Glucuronides / Q000737:chemistry*; D006801:Humans; D009288:Naproxen / Q000097:blood; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D020719:Glucuronides; D009288:Naproxen