Analysis of impurities in vertilmicin sulfate by liquid chromatography ion-trap mass spectrometry

The characterization of impurities present in vertilmicin by liquid chromatography (LC) coupled with mass spectrometry (MS) is described. A reversed phase (RP)-LC method using a C18 column resistant to basic pH with an alkaline (pH 11) aqueous mobile phase was developed and coupled to MS with an electrospray ionization (ESI) source in the positive ion mode which provides MSn capability. In total, 18 impurities were detected in a commercial sample. Eleven impurities described in this work were newly identified.

Main ion trap mass fragmentation pathways of vertilmicin.Figure optionsDownload as PowerPoint slideHighlights
► An LC/MS method for characterization of impurities in vertilmicin was developed.
► The impurity profile of vertilmicin sulfate was reported for the first time.
► 18 impurities, of which 11 new ones, were detected and identified in a bulk sample.
► Alkaline mobile phase reduces ion suppression and improves MS sensitivity.