Different questions, different evidence
LC-MS can support identity through mass and chromatographic evidence. HPLC with an appropriate detector can report chromatographic purity. The laboratory's method and interpretation determine what each result supports.
Compare more than the percentage
- Does the certificate apply to the lot you would receive?
- Who issued it, and can the report be verified?
- What methods and units are stated?
- Are supporting spectra or traces available?
- Was measured content tested separately?
Know the limits of peak-area purity
A chromatographic peak-area percentage is method-dependent. It is not automatically the percentage of the vial's total mass that is the target material, and it does not describe substances the method does not detect.
A better requestAsk for the certificate and methods for the actual lot, not just a headline purity number. Review the results against your research requirements.