HPLC: how clean is the sample?
Chromatography separates components over time. A dominant peak with smaller secondary peaks may indicate high chromatographic purity, but the result depends on the method, detector and calculations.
LC–MS: does the mass match?
Mass spectrometry measures mass-to-charge ratio. Agreement with the expected value supports identification and can reveal certain variants or impurities.
Why are both useful?
A sample may show one dominant peak but still be the wrong compound. It may also have the expected mass while containing additional components. Together, HPLC and LC–MS reduce uncertainty.
What should you ask the supplier?
Request the report for the specific batch, complete chromatogram, mass spectrum, test date and confirmation of whether an external laboratory performed the analysis.