Understanding how to read a peptide certificate of analysis (COA) is a fundamental skill for Canadian peptide researchers. A COA is the quality document that accompanies research-grade peptides to verify their identity, purity, and concentration. Without being able to interpret a COA, researchers cannot verify whether their peptide meets the standards required for reliable research results. This guide explains the key elements of a peptide COA and what to look for when evaluating research compound quality.
HPLC Purity Analysis
High-performance liquid chromatography (HPLC) is the primary method for determining peptide purity. The HPLC chromatogram shows peaks for different components in the sample, and purity is calculated as the percentage of total peak area corresponding to the target peptide. Research-grade peptides should show ≥98% purity on HPLC. A single sharp peak with minimal impurity peaks indicates high-quality synthesis. Canadian researchers should request HPLC data for every peptide batch.
Mass Spectrometry Verification
Mass spectrometry (MS) verifies the molecular identity of the peptide by confirming its molecular weight matches the theoretical mass of the target sequence. A COA should show the observed molecular ion mass within ±1 Da of the theoretical value. MS confirms the peptide is what it claims to be, while HPLC confirms its purity. Both tests together provide comprehensive quality verification for Canadian research use.
What to Look For
A complete peptide COA should include: peptide name and sequence, lot number, synthesis date, HPLC purity percentage, HPLC chromatogram image, MS spectrum image with observed and theoretical molecular weights, and storage recommendations. EhBuddy Peptides provides COA documentation for all research compounds sold in Canada.
Reading a peptide COA correctly ensures Canadian researchers source only verified, research-grade compounds for their laboratory work — protecting experimental validity and reproducibility.
