Rapid identification of drug degradation products directly in a mixture is important in the pharmaceutical industry.  Elemental connectivity and functional group information of the components can be obtained from spectroscopic techniques, such as IR and NMR.  However, these methods require the isolation of the individual components within the mixture before analysis.  Further, due to the low sensitivity of these spectroscopic methods, large sample amounts are required to complete the elucidation process.  Alternative mixture analysis techniques that allow for a more efficient and direct detailed description of the functional groups within an unknown mixture are desirable.  Mass spectrometry (MS), when coupled to HPLC and ESI, circumvents the need for prior mixture component isolation and requires only a small sample amount for analysis.  Also, MS allows for the employment of structure characterization methods, such as collision-activated dissociation (CAD) and exact mass measurements, which provide connectivity and elemental composition information for the protonated mixture components.  We report here a new method which allows for the identification of the amido functionality in protonated monofunctional analytes.  A neutral aminoborane reacts in MS with protonated amides to derivatize the amido functionality.  Reactions of protonated amines and monofunctional-oxygen containing compounds with the borane were studied – none of these compounds react with the aminoborane.  Therefore, the ability to distinguish protonated amides from other protonated nitrogen- and oxygen-containing functionalities is possible via boron-derivatization reactions.