Method
How a batch
becomes a number.
Every product on the catalog has a purity percentage. That percentage doesn't come from a marketing department. It comes from a column, a detector, a signed report. Here's the full chain.
A vial is sampled
When a fresh batch arrives, a small aliquot is drawn from the lyophilized vial and dissolved in HPLC-grade solvent (typically a water-acetonitrile mix with a trace of trifluoroacetic acid). The dissolved sample becomes the “mobile phase loading” — what we actually push through the column.
The column separates everything
The sample is injected into a reversed-phase HPLC column. The column's stationary phase (C18-bonded silica is standard for peptides) interacts with different molecules at different strengths — so different compounds travel through the column at different speeds. Pure target compound emerges as a single tight band.
A detector measures what comes out
A UV detector at the column exit reads light absorption at a peptide-friendly wavelength (215 nm for the peptide bond is the common choice). As each separated band passes the detector, the signal spikes. The resulting plot is a chromatogram — time on the X axis, detector signal on the Y axis.
The math is simple
Purity is the area under the main (target) peak as a percentage of the total area under all peaks. A 99.4% verified batch means 99.4% of the integrated UV signal came from the target compound. Everything else — impurities, byproducts, stray peaks — sums to less than 0.6%.
Purity calculation
Area under the main peak as a percentage of total integrated signal. Reported to the decimal, signed by the lab.
The certificate is generated
The lab generates a Certificate of Analysis: compound identity (confirmed by mass spectrometry), HPLC purity percentage, batch identifier, test date, lab signature. We publish that COA on the product page the moment it lands — unchanged, unfiltered, available for download.
Certificate of Analysis
— illustrative —
Analyst signature
Janoshik Analytical
Below 98%, it doesn't ship
We have an internal floor: any batch that tests below 98.0% HPLC purity is rejected and never made available for purchase. The ledger aggregate “Below threshold: 0 ever” counts those rejections. They're documented; the failed batches just never make the catalog.
Floor & acceptance
Every bar above the dashed line is a shipped batch. Anything below — never made the catalog.
A vial is sampled
When a fresh batch arrives, a small aliquot is drawn from the lyophilized vial and dissolved in HPLC-grade solvent (typically a water-acetonitrile mix with a trace of trifluoroacetic acid). The dissolved sample becomes the “mobile phase loading” — what we actually push through the column.