Why this matters
The HPLC Certificate of Analysis is the single most important trust artefact in the research-peptide market. It's the answer to "what's actually in the vial." Everything else - the supplier's website, the brand, the customer service - is downstream of whether the analytical evidence can be trusted.
The problem is that most buyers have never looked at an HPLC report before, so they have no idea what they're looking at when one arrives in the box. The result is a market where forged reports circulate easily because nobody is checking the details.
This article fixes that. By the end you'll be able to read any Janoshik report (and most reports from comparable third-party labs), spot the parts that matter, and verify the report's authenticity directly against the issuing lab.
If you've not yet read our companion piece, What HPLC actually means covers the underlying chromatography in plain English. This article assumes you already know what HPLC is and goes straight to the "now what does this report say" question.
The anatomy of a Janoshik report
A standard Janoshik Analytical HPLC Certificate of Analysis is a single PDF page (occasionally two if MS confirmation is included separately) with six sections that always appear in roughly the same order. We'll walk through each.
Section 1: Header
SECTION 1 Header
What you'll see at the top of the page
- Janoshik Analytical logo and lab address (Sokolovská, Praha, Czechia)
- Report title: "Certificate of Analysis" or "Analytical Report"
- Report date and report number (sequential)
- Verification key: alphanumeric string, typically 8-12 characters, often near the batch ID. This is the field that lets you authenticate the report against Janoshik's public records.
What to check: the verification key is present and the report date is within the last ~12 months (HPLC reports older than that should be re-tested for any current-shipment claim).
Section 2: Sample identifiers
SECTION 2 Batch identifiers
- Sample name: the peptide as named by the supplier (e.g., "Retatrutide 10mg")
- Batch / Lot number: a code unique to this batch from this supplier (e.g.,
02BWP26R) - Received date and analysis date
- Submitted by: the supplier name (must match the supplier you're ordering from)
What to check: the batch / lot number on the report must exactly match the batch number printed on the vial label you received. If they don't match, the report is for a different batch than the vial in your hand. That can happen innocently (a paperwork mix-up) or non-innocently (the supplier reused an old report from a tested batch to cover an untested one). Either way, ask the supplier to clarify.
Section 3: The chromatogram
This is the visual heart of the report. The chromatogram is a graph showing the detector signal as a function of time after injection.
If you've never seen one, it looks something like this (illustrative ASCII):
SECTION 3 Chromatogram
- X axis: retention time (minutes). Different compounds elute (come off the column) at characteristic times depending on their polarity and the gradient method used.
- Y axis: absorbance signal in milliabsorbance units (mAU), measuring how much UV light the eluent is absorbing at the detector.
- The big peak at the characteristic retention time for the target peptide is where most of the area-under-the-curve comes from. For a 99% pure peptide, this peak dominates the chart.
- Smaller peaks at other retention times are impurities: synthesis byproducts, truncated sequences, deamidation products, or degradation products.
What to check: a real chromatogram has visible baseline noise. A perfect, totally flat baseline with one impossibly clean peak is a reproduction artefact (someone has recreated a fake chart in an illustrator program rather than scanning a real instrument output). Real HPLC traces are slightly messy.
Section 4: Purity percentage
SECTION 4 Purity result
- Purity: typically quoted to one decimal place, e.g.,
99.4% - Method: the HPLC method used (column type, mobile phase gradient, detection wavelength). For peptides, typically a reverse-phase C18 column with an acetonitrile / water + 0.1% TFA gradient at 220 nm UV detection.
What to check: reported purity is consistent with the chromatogram (a 99% purity claim with a chart showing equally-sized peaks would be a red flag). Method is detailed enough that a competent analyst could reproduce it. Be suspicious of round numbers like "99.0% exactly" or "99.99%" with too many zeros - real HPLC integration produces fractional values (99.3%, 99.8%, 98.6%).
Section 5: Impurity table
SECTION 5 Impurity table
Lists each non-target peak with retention time and integrated percentage. For a 99.4% pure peptide:
- Target peptide peak: 99.4%
- Impurity 1 (RT 8.2 min): 0.3%
- Impurity 2 (RT 12.7 min): 0.2%
- Impurity 3 (RT 18.4 min): 0.1%
What to check: impurity percentages sum to roughly (100% - purity%). Any single impurity over 0.5% is worth flagging in your lab notes for the experiment, even if total purity is acceptable, because the impurity might co-elute or interact with downstream assays. Total absence of an impurity table is a yellow flag - real HPLC integration always picks up small noise peaks.
Section 6: Mass spectrometry confirmation (where included)
SECTION 6 MS confirmation
Not every report includes mass spec. When it does, you'll see:
- Expected mass: the calculated molecular weight of the peptide
- Observed mass: the m/z (mass-to-charge) value detected by the MS instrument, often as multiple charge states ([M+H]+, [M+2H]2+, [M+3H]3+ for larger peptides)
- Match status: whether the observed mass matches the expected mass within instrument tolerance (typically ≤1 Da for low-resolution MS, ≤0.01 Da for high-resolution)
Why this matters: HPLC measures purity but not identity. In principle, a 99% pure sample of the wrong compound is possible. MS confirmation closes that gap. A 99% HPLC purity result with a correct MS match is a much stronger evidence chain than HPLC alone. For high-stakes research, insist on MS-confirmed reports.
Now verify it independently
The single most important step: take the verification key from Section 1 and authenticate it against Janoshik's own portal at janoshik.com. The portal returns either a match (the report exists in their records exactly as printed - confirms authenticity) or no match (the key is invalid or the report is forged).
If a supplier cannot direct you to a working verification flow, the report is either forged or from a lab that doesn't issue verification keys. Either way, treat the supplier with extreme caution.
Red flags in fake reports
What forgeries look like
- No verification key. The single biggest tell. Real Janoshik reports always carry one.
- Verification key fails on the portal. If the key returns "no match", the report is forged.
- Identical chromatograms across different batches. Real synthesis batches have slightly different impurity profiles. If two reports for the supplier's "different batches" have the same peaks at the same retention times with the same percentages to one decimal place, one of them was copy-pasted.
- Too clean a baseline. Real HPLC charts have visible baseline noise from the detector. A perfectly flat baseline is illustrator output, not instrument output.
- Round-number purities to too many zeros. "99.99%" or "100.0%" purities aren't reported by real integration software. Genuine results read like 99.3% or 98.7%.
- Inconsistent fonts in the report. A genuine PDF generated by Janoshik's reporting system has consistent typography. A forgery often has the lab logo and original template in one font but the batch ID and purity result pasted in a different one.
- Batch number on report doesn't match the vial. If they don't match, you have a report for a batch you didn't receive. Hard fail.
- Watermarks or "DRAFT" labels. Real production reports don't carry draft watermarks. If you see one, the supplier sent the wrong file.
What to do if a report fails verification
If you've put the verification key into Janoshik's portal and it returns "no match", do not use the contents of the vial. Stop, photograph everything (the printed report, the vial label, the verification result), and contact the supplier to request a replacement vial with a verifiable batch report.
A legitimate supplier should respond within 24 hours and either explain the discrepancy (a typo in the verification key on the printed copy is the most common innocent explanation) or supply a fresh report. If the supplier cannot produce a verifiable report within a reasonable timeframe, the working assumption should be that the original report is forged.
In that case: dispose of the vial as laboratory waste, request a refund (see our supplier verification guide for how to handle bank transfer recovery), and consider reporting the supplier to Action Fraud.
How we handle this at Black & White Peptides
Honest position rather than marketing pitch: we use Janoshik Analytical for HPLC verification of the compounds we test, with verification keys printed on every report. We publish sample reports on our Purity page so you can practise reading them before you ever order. Where a Janoshik report has been issued for the current batch of a compound, we supply that report with the order. Where a report is not yet available for the current batch (we are still expanding our testing coverage), we say so transparently rather than ship without disclosure.
That last bit is unusual in this market. Most suppliers either claim universal coverage they don't have, or stay silent on the testing question entirely. We'd rather under-promise on this and let you check.
FAQ
What is a Janoshik HPLC report?
A Janoshik HPLC report (Certificate of Analysis or COA) is a third-party analytical document produced by Janoshik Analytical, a Czech specialist peptide analysis lab. It records the high-performance liquid chromatography purity result for a specific batch of a peptide, alongside batch identifiers, the analytical method, and where applicable a mass spectrometry confirmation of molecular weight. Janoshik is the de facto industry-standard third-party lab for the UK and EU research-peptide market.
What does 99% HPLC purity actually mean?
It means the area under the chromatogram peak corresponding to the target peptide accounts for 99% of the total integrated peak area in the sample. The other 1% is impurities: synthesis byproducts, truncated sequences, deamidated variants, or degradation products. The difference between 95% and 99% purity is not 4% - it is a fivefold reduction in impurity load, which is meaningful in laboratory work.
How do I verify a Janoshik report is authentic?
Locate the verification key in the report header (an alphanumeric string typically printed near the batch ID and report date). Type or scan the key into Janoshik's public verification portal at janoshik.com. The portal will return either a match (report is authentic) or no match (forged or invalid). A legitimate supplier directs you to do this verification rather than asking you to take their word.
What is mass spectrometry confirmation?
Mass spectrometry (MS) measures the mass-to-charge ratio of molecules in the sample, allowing the analyst to confirm that the target peak in the HPLC chromatogram has the molecular weight expected for the named peptide. A 99% HPLC purity result with a correct MS confirmation is much stronger evidence than HPLC alone, because HPLC measures purity but not identity - a 99% pure sample of the wrong compound is theoretically possible. MS closes that gap.
Are Janoshik reports the only acceptable third-party HPLC reports?
No. Janoshik is the most common in the UK / EU research-peptide market because of its specialism in peptide analysis, but Alphalab International and Akums Analytical also produce legitimate third-party reports used by reputable suppliers. The criteria are the same: independent (not the supplier's in-house chemist), published with batch identifiers, verifiable against the lab's own records, and transparent about analytical method.
What should I do if a report fails verification?
Do not use the contents of the vial. Contact the supplier and request a replacement vial with a verifiable batch report. A legitimate supplier should respond within 24 hours and either explain the discrepancy (occasionally a key is mistyped) or supply a fresh report. If the supplier cannot produce a verifiable report, dispose of the vial as laboratory waste, request a refund, and consider reporting the supplier - see our supplier verification guide.