LC-MS/MS is the gold standard for the quantitation of drugs and metabolites in biological matrices. Chromatography and mass spectrometry separate compounds by exploiting very different physical properties. For this reason, they are considered orthogonal separation techniques. A very high level of selectivity and sensitivity is often achieved.

In metabonomics, analytes often provide no abundant fragments or only non-specific fragments. Interferences often restrict the lower limit of quantitation, or create demands for lengthy chromatographic runs.

FAIMS (high-Field Asymmetric waveform Ion Mobility Spectrometry) separates gas-phase ions at atmospheric pressure by exploiting differences in the ion mobility at high vs. low electric field. Transferring ions from the LC into the MS, FAIMS electrodes offer improved quantitation limits, increasingly selective analysis, and the separation of isobaric interferences.

This presentation will outline some advantages of LC-FAIMS-MS and MS/MS, including the separation of unstable metabolic interferences (a glucuronide and a halo-N-oxide) during pharmaceutical and metabolite quantitative bioanalysis.