Analytical testing is a chain of evidence, not a single purity number. This guide explains what common methods can establish, where they fail and how to judge whether a conclusion is proportionate to the data.
Method map
Reversed-phase HPLC
Separates components according to their interaction with the stationary and mobile phases. It can describe chromatographic purity under the stated conditions, but co-elution, detector response differences and method selectivity can change the interpretation.
Liquid chromatography–mass spectrometry
Combines separation with mass-to-charge measurements and can support molecular-identity assignments. Adducts, fragments, charge states, resolution and calibration must be interpreted correctly.
Orthogonal tests
Water content, residual solvents, counter-ion content, elemental impurities, sterility and endotoxin require different validated methods. None can be inferred from a clean chromatogram alone.
Validation principles
Fitness for purpose depends on specificity, range, linearity, accuracy, precision, robustness, detection capability and an appropriate reference standard. The method and acceptance criteria should be defined before interpreting results.
Source-of-truth standard
Elite Peps Australia does not publish vendor marketing claims as analytical conclusions. We prioritise complete reports, identifiable methods, traceable laboratories and standards such as ICH Q2(R2). Start with Analytical Reports & Certificates of Analysis and our Laboratory Science hub.