Understanding Certificate of Analysis (COA) Documents

What is a Certificate of Analysis?

A Certificate of Analysis (COA) is an official document providing detailed testing results for a specific batch of peptides. It verifies quality and helps researchers confirm products meet specifications.

Key Components of a COA

1. HPLC Analysis

Purity percentage:** 95%+ standard; 99%+ premium

Chromatogram:** Visual representation of purity - Main peak = Your peptide; Small peaks = Impurities

2. Mass Spectrometry (MS)

Theoretical MW:** Expected molecular weight

Observed MW:** Actual measured weight

Difference:** Should be

<1 Da

3. Additional Information - Batch/Lot number - Manufacturing and expiration dates - Physical appearance - Storage recommendations

How to Interpret Purity Results

**99%+:** Excellent - suitable for sensitive research **95-98%:** Standard - acceptable for most applications **

<95%:** Lower quality - may affect results

Red Flags to Watch For

⚠️ Missing COA ⚠️ Generic COA (same for multiple batches) ⚠️ No batch number ⚠️ Inconsistent molecular weight ⚠️ No chromatogram provided

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*Always review COAs before using peptides in research.*