Identification and subsequent removal of an interference by FAIMS in the bioanalysis of dianicline in animal plasma.

The determination of pharmacokinetic parameters requires accurate and reliable bioanalytical methods. Even using highly selective MS/MS, interferences can occur. This paper describes the source of some of these interferences with an example discussed involving the problem of a ketamine interference in a plasma assay.,The introduction of field asymmetric waveform ion mobility spectrometry (FAIMS) removed the interference, enhanced signal-to-background and met GLP acceptance criteria. Relative to the non-FAIMS method, assay calibration characteristics were improved. The FAIMS source gave optimal performance following the introduction of a split in order to reduce the inlet flow to approximately 0.4 ml/min.,The introduction of ion-mobility separation into a bioanalytical LC-MS/MS method can remove unexpected isobaric interferences without the need to redevelop the chromatography.