The effect of micro-organisms on ghost peaks in a reversed phase HPLC system

Abstract

This study involved the analysis of a reversed-phase gradient HPLC related substances method that has been observed to give rise to ghost peaks, which tend to obstruct chromatogram results. The interference of ghost peaks in a related substances analysis is more complicated than in an assay determination. An assay determination chromatogram results in one large peak (API) and many other smaller peaks that do not effect the analysis. On the other hand the important peaks in a related substances determination are much smaller and most notably often have a similar peak height to ghost peaks, which might effect any interpretation of results. Through previous investigations carried out on ghost peaks in a reversed phase gradient HPLC related substances method, some light has been shed on the true nature and source of these peaks, which tend to be contaminants in the form of microorganisms that are of airborne origin. The objective of this study was therefore to devise a suitable HPLC-friendly chemical sanitization method in an attempt to achieve a ghost peak free chromatogram.