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HPLC Testing
Reversed-phase high-performance liquid chromatography (RP-HPLC) is the analytical standard for peptide purity verification. The technique separates the target peptide from synthesis impurities based on differences in molecular polarity, using a C18 stationary phase and an aqueous-organic mobile phase gradient.
UV detection at 220nm -- the characteristic absorbance wavelength of the peptide bond -- generates a chromatogram where each compound appears as a distinct peak at its retention time. The sharper and more isolated the target peak, the higher the sample purity.
The resulting chromatogram provides a quantitative measure of sample composition -- the purity percentage reflects the proportion of target peptide relative to all detected compounds. This is calculated as target peak area divided by total peak area, expressed as a percentage.
Sample Preparation
Peptide sample dissolved in mobile phase solvent system
Column Separation
Injected into C18 reversed-phase column; compounds separate by hydrophobicity
Gradient Elution
Increasing organic solvent concentration elutes compounds at characteristic retention times
UV Detection
Peptide bond absorbance measured at 220nm; chromatogram peak generated
Purity Calculation
Target peak area divided by total detected area yields purity percentage
Mass spectrometry diagram coming soon
Mass Spectrometry
While HPLC measures how pure a sample is, ESI-MS (electrospray ionization mass spectrometry) confirms what it is. A sample can be 99% pure but be the wrong compound. Mass spectrometry eliminates this possibility by comparing the measured molecular weight against the theoretical weight of the peptide sequence.
The ESI-MS process ionizes the peptide and measures its mass-to-charge ratio with high precision. Agreement between observed and theoretical molecular weight -- typically within 0.1 Da -- provides definitive identity confirmation independent of the HPLC purity measurement.
Two tests. One certainty.
HPLC quantifies purity. Mass spectrometry confirms identity. Together, they verify both the composition and the correct compound.
99%+
Purity Guarantee
RP-HPLC verified on every production batch
Every Batch Tested
No batch ships without a passing HPLC result. No exceptions.
Lot-Specific COAs
Every order includes a Certificate of Analysis tied to the specific lot number.
Retained Samples
Reference samples retained for 24 months for independent re-verification.
Beyond Purity
Endotoxins -- bacterial lipopolysaccharides released during cell lysis -- are not detected by HPLC. A sample can pass purity testing at 99%+ and still carry significant endotoxin contamination. For research applications involving cell culture, animal models, or injection-based protocols, endotoxin levels are a critical quality parameter.
The Limulus Amebocyte Lysate (LAL) assay is the industry-standard method for endotoxin detection. The assay exploits the clotting cascade of horseshoe crab blood cells, which react to even trace levels of bacterial endotoxin. Results are reported in endotoxin units per milligram (EU/mg).
Most research-use-only peptide suppliers stop at HPLC purity. Peptari performs LAL endotoxin testing as a standard part of our quality protocol -- not as an add-on or premium option.
< 1 EU/mg
Endotoxin threshold — LAL assay verified
Reading a COA
We don't just provide COAs -- we help you understand them. Below is a sample COA with annotations explaining each field.
PEPTARI RESEARCH
Certificate of Analysis
Product Information
Test Results
For Research Use Only — Not for Human or Veterinary Use
Authorized: [Lab Director Signature]
Identity
The full chemical name and common name of the peptide. This confirms the product matches what was ordered.
Sequence Verification
The single-letter amino acid sequence confirms the peptide was synthesized with the correct primary structure.
Lot Traceability
Every production batch receives a unique lot number. This enables full traceability from synthesis to shipment.
Production Date
The manufacturing date anchors the stability window and helps determine shelf life for storage planning.
Visual QC
A visual inspection confirms expected physical characteristics. Discoloration or unusual texture indicates potential degradation.
Primary Purity Metric
Reversed-phase HPLC quantifies the proportion of target peptide relative to all detected compounds. This is the primary quality metric.
Identity Confirmation
Mass spectrometry measures the molecular weight. Agreement with theoretical weight confirms the correct compound was synthesized.
Microbial Safety
The LAL assay detects bacterial endotoxins not visible on HPLC. Critical for cell culture and in vivo research applications.
Handling Instructions
Recommended storage conditions to maintain stability and prevent degradation of the lyophilized product.
Every Peptari order ships with a lot-specific COA. Request a sample to see our documentation firsthand.
Independent Verification
In addition to comprehensive in-house analytical chemistry, Peptari submits samples to independent third-party laboratories for verification. This dual-layer approach ensures that our internal quality standards are validated by an unaffiliated analytical team with no commercial interest in the results.
Third-party verification follows the same analytical methods used in-house: reversed-phase HPLC for purity quantification and ESI-MS for molecular identity confirmation. Randomly selected batches are submitted for independent analysis, and results are cross-referenced against our in-house data.
Independent analytical laboratory (name disclosed upon request)
Third-party results are available upon request for any lot number.
Manufacturing Standards
GMP Compliant
In-House Analytics
Cold-Chain Logistics
Batch Documentation
Controlled Access
Good Manufacturing Practice (GMP) compliance in peptide production means every step from raw amino acid sourcing through final lyophilization follows documented, auditable procedures. Synthesis occurs in controlled clean room environments with monitored temperature, humidity, and particulate levels.
Standard operating procedures govern every production phase: reagent preparation, solid-phase synthesis, cleavage and deprotection, purification, lyophilization, and packaging. Batch records are maintained for full traceability, and equipment calibration is performed on documented schedules.
Environmental monitoring programs track viable and non-viable particulates in production areas. Personnel access is restricted to trained operators following gowning protocols. These controls collectively ensure consistency and contamination prevention across every production batch.