title: Utilization of hydrophilic-interaction LC to minimize matrix effects caused by phospholipids.
abstract: BACKGROUND
  In bioanalysis, phospholipids may affect the precision and accuracy of LC-MS/MS methods and compromise the quality of the results, especially when samples in complex biomatrices are extracted by protein precipitation techniques.
  
  
  RESULTS
  It was found that the retentive behavior of both common pharmaceuticals and physiologically relevant phospholipids under bare silica hydrophilic-interaction LC (HILIC) is more predictable than under reversed-phase conditions. In particular, the retention time of phospholipids was not significantly affected by varying the salt and acid modifiers in the mobile phases, but common pharmaceuticals can be shifted away from these phospholipid interferences through mobile phase modifiers. Several mass spectrometric techniques were applied to confirm this finding.
  
  
  CONCLUSIONS
  HILIC chromatography is a valued tool in the development of robust bioanalytical assays with minimal and predictable phospholipid interferences. Furthermore, addition of a small amount of ion-pairing additives can reliably move pharmaceutical compounds away from these suppressive regions.
authors.affiliation: Dynamics & Metabolism Department, Pfizer Global Research & Development, Groton, CT 06340, USA. beijing.tan@pfizer.com
authors.forename: Beijing
authors.initials: B
authors.lastname: Tan
authors.forename: Andre
authors.initials: A
authors.lastname: Negahban
authors.forename: Thomas
authors.initials: T
authors.lastname: McDonald
authors.forename: Yizhong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Christopher
authors.initials: C
authors.lastname: Holliman
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid / Q000379:methods* / Q000592:standards; D057927:Hydrophobic and Hydrophilic Interactions; D004364:Pharmaceutical Preparations / Q000097:blood; D010743:Phospholipids / Q000097:blood* / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D053719:Tandem Mass Spectrometry / Q000379:methods* / Q000592:standards; D014269:Trifluoroacetic Acid
chemical_list: D004364:Pharmaceutical Preparations; D010743:Phospholipids; D014269:Trifluoroacetic Acid