RP-HPLC purity analysis from $150 with LC-MS identity confirmation
A step-by-step guide from an independent peptide testing lab: reverse-phase HPLC-UV at 214 nm plus LC-MS confirmation, 0.1% impurity detection, and a third-party COA in 9-11 business days. Ship from anywhere in the U.S.
To test peptides for purity, ACS runs reverse-phase HPLC with UV detection and confirms identity by LC-MS/MS. Methods are validated to ICH Q2(R1) and USP guidelines. Every report includes the chromatogram, calculated purity percentage, and an impurity profile down to 0.1%. This is the same peptide testing method used by pharmaceutical QC labs, delivered as an independent, third-party COA for compounding pharmacies, research institutions, and biotech companies across the United States.
High-resolution reverse-phase HPLC with UV detection for accurate peptide purity quantification. Typical detection limits of 0.1% for impurities with comprehensive chromatographic profiling.
Liquid chromatography coupled with tandem mass spectrometry for detailed molecular characterization and identification of peptide impurities and degradation products.
Accurate quantification of target peptide purity using validated HPLC methods with multiple detection wavelengths
Identification and characterization of deletion sequences, truncated peptides, and synthesis byproducts
All analytical methods validated according to ICH guidelines ensuring reproducibility and accuracy
Comprehensive report including chromatograms, mass spectra, purity percentage, and expert interpretation
These are the actual parameters behind every purity percentage we report. Method conditions are adjusted per peptide (hydrophobicity, length, salt form), but the framework below applies to standard research peptides and GLP-1 analogs alike.
| Parameter | Specification |
|---|---|
| Technique | Reverse-phase HPLC with UV detection (RP-HPLC-UV) |
| Detection wavelength | 214 nm primary (peptide bond), 280 nm secondary for Trp/Tyr-containing sequences |
| Column | C18, 5 um, typically 4.6 x 250 mm; C4 or C8 for highly hydrophobic peptides |
| Mobile phase | Water/acetonitrile gradient with 0.1% TFA or formic acid ion pairing |
| Purity calculation | Target peak area / total integrated peak area x 100 (area percent) |
| Impurity detection limit | 0.1% of total peak area; reporting range 50%-99.9% |
| Identity confirmation | LC-MS / ESI-MS molecular weight match against theoretical mass |
| Method basis | Validated in line with ICH Q2(R1) and USP <621> chromatography principles |
| Sample required | 100-500 ug lyophilized powder, or 1 mL of reconstituted solution |
| Price and turnaround | From $150 per sample; 9-11 business days from receipt |
A purity percentage on its own does not tell you whether material is fit for use. Read it alongside the impurity profile and the identity confirmation.
| HPLC purity | What it usually means |
|---|---|
| 99%+ | Clean synthesis and good purification. Typical target for compounding-grade and reference material. |
| 98-99% | Standard for reputable research peptides. Minor synthesis-related peaks near the main peak. |
| 95-98% | Usable for many research applications, but impurities should be identified before quantitative work. |
| Below 95% | Visible secondary peaks. Commonly incomplete coupling, deletion sequences, or degradation in transit or storage. |
| High purity, wrong mass | A pure compound that is not your peptide. Only LC-MS identity confirmation catches this. |
No. Purity is a chromatographic measurement, so it cannot be produced without an HPLC system, a validated gradient, and a reference standard. Home checks tell you something about the material, but not its purity:
The practical route is mail-in analysis: ship 100-500 ug overnight and get the chromatogram, purity percentage, impurity profile, and mass confirmation on one signed report. See the full step-by-step purity testing method, or start with how to get peptides tested.
No kit measures peptide purity. The products sold as peptide purity testing kits or peptide test kits are reconstitution and reagent color checks. They can flag an obviously wrong substance, but they cannot separate your peptide from deletion sequences, truncated chains, acetate or TFA salt, or residual solvent, and they never return a percentage you can put on a certificate.
Peptide purity testing costs $150 per sample for RP-HPLC purity with a signed certificate of analysis. There is no minimum order and no membership, and the price does not change by state because every sample is analyzed at our single Florida laboratory. Adding identity, contaminant, or moisture testing to the same vial costs less than running the tests separately.
| Test | What it answers | Price |
|---|---|---|
| HPLC purity | Percentage of target peptide vs. related impurities | From $150 |
| Purity + LC-MS identity | Purity plus confirmation the mass matches the sequence | Bundled per sample |
| Endotoxin, heavy metals, moisture | Contamination and water content on the same vial | Priced per test |
Cheaper is not always cheaper: a purity number without a chromatogram, a stated wavelength, or an impurity table cannot be checked by you or by a regulator. Compare what is actually included before you compare price. See the full peptide testing cost breakdown by test, or compare peptide testing companies before you ship.
Working through a supplier certificate instead? Verify the COA line by line before paying for a retest.
Send your peptide name, sample count, and the tests you need. We return a fixed-price quote, usually within one business day.
ACS Peptide Testing Labs provides peptide purity testing to researchers and companies in all 50 US states from our Florida laboratory. Simply ship your peptide sample overnight and receive your HPLC purity results electronically within 9–11 business days. Our nationwide peptide purity testing service reaches every US metro so you can access professional-grade analysis from anywhere.
Overnight FedEx/UPS from all 50 states to our Florida lab.
Standard turnaround.
Comprehensive Certificate of Analysis delivered electronically.
Popular pickup regions for mail-in purity testing: peptide purity testing in California, peptide testing in Texas, peptide testing in Florida, Houston, Dallas, and Miami.
The HPLC method behind every purity percentage, step by step.
Mail-in labs, university cores, and CROs compared.
Step-by-step guide with costs and timelines.
Line-by-line walkthrough of a real chromatogram.
What you actually pay for and why.
Where manufacturer certificates fall short.
Compare the two main peptide testing methods.
How to verify any supplier's certification.
Submit your samples for professional HPLC purity analysis. Fast turnaround, accurate results, and comprehensive Certificate of Analysis.