High-Performance Liquid Chromatography (HPLC) is the primary analytical method for determining peptide purity. A properly conducted HPLC analysis separates the target peptide from synthesis impurities, deletion sequences, and degradation products.
Key parameters to evaluate include: retention time, peak area percentage, method conditions (column type, gradient, mobile phase), and injection volume. Purity ≥98% by HPLC area normalization is considered research-grade.