HPLC purity testing

Reversed-phase HPLC separates components by hydrophobicity. The laboratory integrates peak areas and compares the principal peak to the sum of significant peaks. Related substances, synthesis by-products, or degradation products may appear as additional peaks; their presence does not by itself indicate a particular source — only what was detected in that vial on the test date.

Purity is reported alongside identity by mass spectrometry and net content in our standard mail-in panel. Together, these three results describe whether the sample appears to match its label, how clean the chromatographic profile looks, and whether the fill weight or volume matches the stated amount.

The certificate of analysis issued by QLD Analytical summarises the laboratory report. The HPLC purity value is shown as a percentage (or as a qualitative statement if the laboratory reports it that way for a particular matrix). The downloadable PDF includes the underlying chromatogram pages from Apex Labs Pty Ltd so you can review peak assignments.

Results apply only to the sample received and consumed during testing. Different batches, storage conditions, or vials are not covered by a single certificate.

• HPLC purity is method-dependent: column chemistry, gradient, and detection wavelength all influence which peaks are visible.
• Co-eluting impurities can be hidden; orthogonal methods (such as mass spectrometry) help confirm identity but do not replace full impurity profiling unless specifically requested.
• Very hydrophilic or large-matrix samples may need different preparation; the laboratory documents any deviations on the report.

Extended impurity panels, blend quantification, endotoxin, and heavy-metals testing are coming soon — on enquiry while scope is confirmed with our laboratory partner.