How to Read a Janoshik COA: Complete Verification Guide
A step-by-step guide to understanding and verifying a Janoshik Certificate of Analysis — what each section means, how to spot issues, and what to do with the results.
What is a Janoshik COA?
A Certificate of Analysis (COA) from Janoshik Analytical is an independent, third-party laboratory report documenting the purity and identity of a peptide or research compound batch. Janoshik is a specialist analytical chemistry laboratory focused on research compound testing — their COAs are the industry standard for research peptide quality documentation.
Every QSC product ships with a Janoshik COA that is publicly verifiable via the Janoshik verification portal. Here’s how to read one.
COA Structure: Section by Section
1. Sample Identification
What to check: The compound name and batch number should match the vial label. QSC submits samples under the compound name and batch code — verify these match your order.
2. HPLC Purity Result
High-Performance Liquid Chromatography (HPLC) separates compounds in a sample by their interaction with a stationary phase. The detector measures the area under each peak — and the purity % is the target compound peak area divided by total area.
Red flags: Purity below 98% without explanation. Multiple large impurity peaks. Purity reported without a chromatogram.
3. Mass Spectrometry (MS) Verification
Mass spectrometry confirms molecular identity — it measures the mass-to-charge ratio (m/z) of the compound and confirms the molecular weight matches the expected value for that peptide sequence.
What to check: The reported [M+H]⁺ or [M+2H]²⁺ ion should match the calculated molecular weight of the compound. For a 10-amino acid peptide, even a 1 Da discrepancy indicates a sequence error or modification.
Why both HPLC and MS matter: HPLC tells you how pure it is; MS tells you what it actually is. A compound can be “99% pure” HPLC but be the wrong peptide entirely if MS is not done. Both are required for meaningful QC.
4. Verification Code
Every Janoshik COA has a unique verification code that can be entered at verify.janoshik.com to confirm the report is genuine and unmodified. This is the most important anti-fraud feature — a COA without a verifiable code cannot be confirmed as authentic.
Frequently Asked Questions
What is the difference between HPLC purity and MS confirmation?
HPLC measures how much of the sample is the target compound (purity %). Mass spectrometry confirms the molecular identity — that the compound is actually what it claims to be by matching the measured molecular weight to the expected value. Both are needed: HPLC alone cannot confirm identity, MS alone cannot quantify purity.
How do I verify a Janoshik COA is genuine?
Go to verify.janoshik.com and enter the unique verification code printed on the COA. A genuine Janoshik COA will return the original report data. QSC links directly to each product’s COA from the product page.
What purity should I expect from a quality research peptide supplier?
≥99% HPLC is the research-grade benchmark. Some compounds are technically more difficult to synthesise and may show 97–98% with a detailed impurity profile. Sub-95% purity without explanation is a quality concern.
What does “MS confirmed” mean on a COA?
It means mass spectrometry was performed and the measured molecular weight matches the expected molecular weight of that peptide sequence — confirming molecular identity. QSC performs MS confirmation on every batch.
