Analytical documentation

Every lot. Two methods. One archive.

Purity and identity are different questions and they need different instruments. We run both on every batch before it is released, and the result is filed against the lot ID printed on your vial.

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Lot lookup

Verify any lot.

Enter the lot ID from your vial or carton. No account required, and you do not need to have ordered — ask us for the current lot on any catalogue item before you buy.

Purity method: RP-HPLC, UV 214 nm
Identity method: LC-MS, ESI+
Release threshold: ≥ 98.0% area
Testing: Third-party, per lot
Archive from: January 2026
Retention: Indefinite

coa — lot lookup

Lot IDs use the format MS- followed by four digits.

Method

Why one test is never enough.

RP-HPLC — purity Reversed-phase liquid chromatography separates the sample and integrates peak area at 214 nm. It reports how much of the material is the principal peak and where the impurities sit. It does not identify the molecule — a pure vial of the wrong compound passes comfortably.

LC-MS — identity Mass spectrometry measures molecular mass against the theoretical mass calculated from the sequence. This is the test that catches substitution, which is the single most common failure in this category.

Release or reject Lots below the 98.0% area threshold, or whose observed mass falls outside tolerance, are quarantined and destroyed. Failed material is never reworked into a subsequent batch.

Reading a certificate

Five checks, in order.

Lot number matches

The certificate must carry the same lot ID as your vial. A generic document for "the product" is not evidence about your batch.

Mass spec is present

Both observed and theoretical mass should be printed as figures. "Identity confirmed" with no numbers is a summary, not a result.

Laboratory is named

An independent lab has a name, an address and a report number. In-house testing is not third-party testing.

Chromatogram included

A purity figure without the trace behind it is an assertion. The trace is the evidence, and it shows where the impurities are.

A longer version of this is in the learning center.

Research Use Only. All products sold by MaxSpan Peptides are supplied strictly for in vitro laboratory research by qualified professionals aged 21 or older. They are not intended for human or animal consumption, clinical use, diagnostic use, veterinary application, or any therapeutic purpose. Statements made on this website have not been evaluated by the U.S. Food and Drug Administration. MaxSpan Peptides is a chemical supplier and is not a compounding pharmacy as defined under Section 503A of the Federal Food, Drug, and Cosmetic Act, nor an outsourcing facility as defined under Section 503B.