Quality6 min read
Understanding Peptide Purity: What HPLC and MS Testing Really Tell You
A breakdown of the two primary analytical methods used to verify peptide identity and purity — and why both matter for reliable research.
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Pep Rally Peptides
The science behind
what we sell.
We built Pep Rally Peptides on one principle: research-grade materials demand research-grade verification. Every vial is tested, documented, and traceable.
Who We Are
Founded for
researchers.
Pep Rally Peptides was built to provide the scientific research community with consistently high-quality peptides. Reliable materials are the foundation of meaningful research — we take that seriously.
We believe in transparency you can check: third-party HPLC and mass spectrometry testing through Janoshik Analytical, with a Certificate of Analysis available for each lot we ship.
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Verified Purity
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Orders with COA
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Independent Tests
Our Process
Four steps. Zero shortcuts.
01
Sourcing & Synthesis
Compounds are sourced for laboratory research use and released only after third-party analytical testing confirms identity and purity for that lot.
We focus on lot-level verification and documentation rather than marketing facility certifications we do not hold.
02
HPLC Analysis
Every batch undergoes High-Performance Liquid Chromatography to confirm peptide identity and measure purity. We require ≥97% before any product moves forward.
HPLC separates peptide components by molecular interaction, producing a chromatogram that reveals exact purity percentage and identifies any impurities present.
03
Mass Spectrometry
Mass spectrometry confirms molecular weight and structural integrity — a second independent verification of compound identity.
MS measures the mass-to-charge ratio of ionized molecules. If the observed molecular weight doesn't match the expected value within tight tolerances, the batch is rejected.
04
Certificate of Analysis
A full COA is generated for every batch documenting purity percentage, testing methodology, and results. Ships with every order — no exceptions.
Each COA includes: compound name, batch number, molecular weight (observed vs. expected), HPLC purity percentage, appearance, solubility data, and testing lab identifier.
Testing & Standards
HPLC
Purity testing by liquid chromatography
MS
Identity confirmation by mass spectrometry
COA
Batch-specific certificate for each lot
Resources
Go deeper.
Common Questions
FAQ
No. All products sold by Pep Rally Peptides are strictly for in-vitro laboratory research and analytical purposes only. They are not approved for human consumption, ingestion, or any form of application to humans or animals.
A COA is a document from an independent laboratory that confirms the identity, purity, and quality of a compound. Every order includes a COA showing HPLC and mass spectrometry results. We ship lots at ≥97% HPLC purity; exact results are on the batch COA.
Each batch undergoes two independent tests: High-Performance Liquid Chromatography (HPLC) to measure purity, and Mass Spectrometry (MS) to confirm molecular identity and structural integrity.
We supply research compounds for U.S. laboratory use. Quality claims are backed by third-party HPLC and mass spectrometry testing (Janoshik Analytical) and batch-specific Certificates of Analysis — not by WHO/GMP or ISO 9001 certification of Pep Rally Peptides.
Lyophilized peptides should be stored at -20°C or below for long-term storage. For short-term storage (under 30 days), refrigeration at 2-8°C is acceptable. Keep vials sealed and away from light and moisture.
Most orders are fulfilled same-day if placed before 2 PM EST on business days. Standard shipping typically arrives within 2-5 business days.
If someone shared a referral link or code with you, it will be applied when you visit through their link, or you can enter it manually in your cart before checkout.
Still have questions?
contact@peprallypeptides.comSee for yourself.
Browse our collection and receive a Certificate of Analysis with every order.