Analytics

Our verification process

Every batch passes through the same seven-step analytical sequence before release. Each step measures a distinct property; no step substitutes for another. Results are published on the batch certificate of analysis.

Fig. 1 — Batch testing sequence, in order of execution

Identity confirmation

The first gate confirms the material is the compound named on the label. Molecular mass is measured by electrospray ionisation mass spectrometry and compared against the theoretical mass of the stated sequence. A deviation beyond ± 0.5 Da indicates a deletion, an incomplete deprotection, or a mislabeled lot — any of these fails the batch before further testing proceeds.

Measures: Molecular mass vs. theoretical (ESI-MS)
A failing result looks like: Observed m/z outside ± 0.5 Da of theoretical mass, or a secondary ion series inconsistent with the stated sequence.

HPLC purity

Reversed-phase high-performance liquid chromatography separates the target peptide from truncated sequences, deletion products, and residual protecting groups. Purity is calculated as the target peak's area relative to total integrated area at 214 nm. A failing result shows one or more impurity peaks whose combined area exceeds 2.0 % of the total.

Measures: Target peak area as % of total area (UV 214 nm)
A failing result looks like: Purity below 98.0 %, or any single unidentified impurity peak above 1.0 %.

Mass spectrometry

Beyond gross identity, MS-MS fragmentation verifies the amino acid sequence itself. Fragment ion series are matched in silico against the expected sequence. This step catches sequence inversions and substitutions that pass a simple mass check because they share the same nominal mass.

Measures: b/y ion series coverage
A failing result looks like: Fragmentation pattern that cannot be reconciled with the stated sequence.

Endotoxin

Bacterial endotoxin is quantified by a kinetic turbidimetric Limulus amebocyte lysate (LAL) assay. Endotoxin contamination is invisible to HPLC and mass spectrometry, so it is tested separately. Results are reported per batch in EU/mg.

Measures: Endotoxin units per milligram (LAL)
A failing result looks like: Any result above the release specification for the compound class is rejected; results are reported, not averaged.

Heavy metals

Inductively coupled plasma mass spectrometry screens for elemental contaminants introduced by catalysts, reagents, or equipment during synthesis. The panel covers arsenic, cadmium, lead, and mercury at minimum, with additional elements where the synthesis route warrants it.

Measures: Elemental concentration, ppm (ICP-MS)
A failing result looks like: Any screened element above its specification limit, reported in ppm per element.

Residual solvents

Gas chromatography with flame ionisation or mass-selective detection quantifies solvents retained after purification and lyophilisation — typically acetonitrile, TFA-related residues, and dichloromethane where used. Limits follow ICH Q3C class guidance for the solvents used in the process.

Measures: Solvent concentration, ppm (GC)
A failing result looks like: Any residual solvent above its class limit, or detection of a class 1 solvent above the quantitation limit.

Moisture content

Coulometric Karl Fischer titration measures residual water in the lyophilised solid. Excess moisture accelerates hydrolytic degradation in storage and distorts net peptide content calculations. Water content is reported as a mass percentage alongside peptide content.

Measures: Water, % w/w (Karl Fischer)
A failing result looks like: Water content above 8.0 % w/w, or a result inconsistent with the stated lyophilisation record.

Summary

Tests, methods, and specifications

Standard analytical panel
Test	Method	Specification	Typical result format
01 — Identity confirmation	ESI-MS	± 0.5 Da	Observed m/z
02 — HPLC purity	RP-HPLC	≥ 98.0 %	Purity % + chromatogram
03 — Mass spectrometry	MS-MS	Full series match	Fragment coverage map
04 — Endotoxin	LAL (kinetic turbidimetric)	Reported, EU/mg	EU/mg value
05 — Heavy metals	ICP-MS	ppm, per element	ppm table
06 — Residual solvents	GC-FID / GC-MS	≤ ICH Q3C limit	ppm per solvent
07 — Moisture content	Karl Fischer (coulometric)	≤ 8.0 %	% w/w

Release criteria

What we reject

Acceptance is binary. A batch that fails any single criterion is not released, re-blended, or discounted. Specificity matters: these are the actual rejection thresholds.

HPLC purity below: 98.0 %
Any single unidentified impurity above: 1.0 %
Mass deviation beyond: ± 0.5 Da
MS-MS sequence mismatch: Any
Heavy metal above spec: Any element
Residual solvent above ICH Q3C limit: Any solvent
Water content above: 8.0 % w/w
Missing or unsigned batch record: Automatic reject

Records produced under this process

Full compound index · Testing methodology · Sourcing standards · Documentation archive

For a field-by-field explanation, read what a complete peptide COA includes.

Guide

What a complete research peptide COA includes

The seven measurements and identifying details to look for in a batch record.

Reference

Our verification process

Methods and acceptance criteria used in the stated analytical panel.

Reference

Documentation & batch records

How certificates and supporting records are organized by batch.

Research use only

For laboratory research use only. Not for human or veterinary consumption. Not a drug, food, or dietary supplement. Not for diagnostic or therapeutic use. All materials referenced on this site are supplied to qualified laboratories and research institutions for in-vitro and analytical work.

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