How to Read a Certificate of Analysis (COA)

What is a Certificate of Analysis?

A Certificate of Analysis (COA) is a document that confirms the identity, purity, and quality of a specific batch of compound. It shows the results of testing performed on your exact lot — not a generic sample.

Key Components of a COA

1. Product Identification

• Compound Name: Full chemical name and common name
• Lot Number: Must match the vial you received
• Test Date: When the analysis was performed
• Molecular Formula: Chemical composition

2. HPLC Purity Analysis

What it measures: The percentage of the compound that is actually the target peptide

• ≥99%: Research-grade standard
• 95-98%: Acceptable for many applications
• <95%: Not suitable for quantitative research

Look for: A chromatogram (graph) showing one dominant peak with minimal impurities

3. Mass Spectrometry (MS) Verification

What it confirms: The molecular identity — that the compound is actually what it claims to be

• Expected m/z: Theoretical molecular weight
• Observed m/z: Actual measured weight
• Match: Should be within 1-2 mass units

4. Physical Properties

• Appearance: Color and physical form (usually white powder)
• Solubility: How it dissolves in different solvents
• pH (if applicable): Acidity/alkalinity of reconstituted solution

5. Additional Testing

• Water Content: Percentage of moisture (should be low)
• Endotoxin Level: Bacterial contamination test (<0.5 EU/mg)
• Heavy Metals: Contamination screening

Red Flags to Watch For

Generic or Missing Information

• ❌ No lot number matching your vial
• ❌ No actual test data, just specifications
• ❌ Same COA for all batches/orders
• ❌ Missing laboratory name or accreditation

Questionable Test Results

• ❌ Purity claims without supporting chromatogram
• ❌ Mass spec results that don't match expected molecular weight
• ❌ Perfect round numbers (99.0%, 100.0%) — real tests show decimal precision
• ❌ Missing method information (HPLC conditions, MS parameters)

Understanding Test Methods

HPLC (High-Performance Liquid Chromatography)

• Purpose: Separates components to measure purity
• Result: Percentage purity and impurity profile
• Method info should include: Column type, mobile phase, detection wavelength

ESI-MS (Electrospray Ionization Mass Spectrometry)

• Purpose: Confirms molecular identity
• Result: Molecular weight confirmation
• Common variations: ESI-MS, MALDI-TOF, LC-MS

Laboratory Standards

Third-Party Testing

Best practice: COAs from independent laboratories that don't sell the compounds

• Higher credibility and objectivity
• Usually includes laboratory accreditation information
• Often more detailed methodology

In-House Testing

Acceptable but less independent: Testing performed by the supplier

• Still valuable if methodology is transparent
• Should include equipment calibration information
• More susceptible to conflicts of interest

OPSEK Labs COA Standards

Every OPSEK Labs product includes:

• ✅ Lot-specific testing — your COA matches your vial
• ✅ Independent third-party analysis by Intertek Pharmaceutical Services
• ✅ HPLC purity analysis with chromatogram reference
• ✅ Mass spectrometry identity confirmation
• ✅ Complete test methodology documentation
• ✅ Endotoxin screening for research safety

How to Verify Your COA

1. Check lot number: Must match your vial exactly
2. Verify laboratory: Independent testing lab listed
3. Review purity: ≥99% with supporting data
4. Confirm identity: Mass spec matches expected molecular weight
5. Check dates: Testing should be recent (within 2 years)

Questions About Your COA?

Our technical team can explain any aspect of your Certificate of Analysis:
Email: support@opseklabs.com
Include your lot number for faster assistance.