HPLC Purity

High-performance liquid chromatography purity assessment quantifies the proportion of a sample's total detected chromatographic response attributable to the...

High-performance liquid chromatography purity assessment quantifies the proportion of a sample's total detected chromatographic response attributable to the main compound peak relative to all other detected impurity peaks, expressed as area percent purity, and represents the single most widely used and regulatorily important purity determination method for pharmaceutical compounds. A well-designed HPLC purity method must adequately resolve the main compound peak from every potential impurity, degradation product, and synthetic by-product likely to be present, achieved through careful optimisation of stationary phase, mobile phase composition and gradient, and detection wavelength; because a compound of interest and a structurally similar impurity can co-elute under an inadequately optimised method and thereby escape detection entirely, HPLC purity methods intended for regulatory reporting must additionally be validated for specificity, addressed later in this phase, before their purity results can be considered reliable.